take phentermine break

Why You NEED To Take a Break from Phentermine

General Phentermine Questions?
Check out the ultimate guide to phentermine weight loss pills!

Phentermine is the most widely prescribed and frequently encountered weight loss medication on the market, now accounting for more than 50% of prescriptions.  While phentermine is very useful and effective in assisting weight loss, it is important to remember that it is recommended for short term use only. This is because it puts pressure on the heart and can increase blood pressure, plus it can be addictive and becomes less effective over time as your body becomes accustomed to its effects. Here we explain more about why phentermine is only prescribed for limited periods of time and the importance of taking a break from phentermine.

Recommended Phentermine Prescription

Phentermine has been available on prescription for the short term management of obesity since it first received FDA approval in 1959. It is recommended that phentermine only be prescribed short-term, typically interpreted as up to 12 weeks. In order to monitor patients, doctors will insist on monthly consultations, or sometimes even fortnightly or weekly appointments, to check that the patient is losing weight at a healthy rate and is not experiencing side effects or additional problems as a result of taking phentermine.  In most cases, if the patient continues to meet the doctor’s criteria and follows the guidelines they have been given then they will then be provided with a further prescription. This is often up to a maximum of three months, as is the case in many states across the US, although this time period can vary depending on the specific laws of the state and of the practices of doctors within that state. Following the 12-week prescription, patients are often instructed to take a 4-week break and may then be prescribed phentermine for a further 12-week period if it is deemed necessary.

How Phentermine Effects the Body

Phentermine is only available on prescription due to being classified as a controlled substance, recognized as having a structure similar to amphetamine. Like amphetamine, phentermine acts on the central nervous system to stimulate the neuron bundles in our brain, including dopamine, epinephrine (adrenalin) and norepinephrine (noradrenalin). This causes phentermine to increase alertness and energy levels, reduce hunger and minimize cravings.

For many patients taking phentermine, the initial effects can be quite aggressive, including feeling ‘wired’ and unable to sleep, with little to no appetite and a variety of side effects. Over time these side effects reduce, as do the effects of appetite suppression and energy boosting. This is because the sustained used of many drugs causes adaptation within the body that tend to lessen the drug’s original effects over time, known as drug tolerance. Many phentermine users experience a reduction in effectiveness of the medication over time, which indicates that tolerance is occurring within the body. As a stimulant, phentermine also causes the heart to work faster as a means to enable the body to work more efficiently. Over time this can put stress on the heart, which can in turn result in symptoms such as chest pains and an increase in blood pressure, amongst other heart-related side effects.

phentermine break

The Importance of Taking a Break

Due to the addicting nature and side effects that phentermine can produce, it is important that phentermine is used for a limited period, ideally until the patient has established a healthy routine which includes a balanced diet and regular exercise. Phentermine is a weight loss aid and therefore will work only in conjunction with a healthy diet and exercise if long-term weight loss is desired. When prescribing phentermine your doctor should also stress the importance of taking this opportunity to use phentermine as a tool to restructure your life into a healthy way of living. This doesn’t mean a fad diet or working-out 3 hours a day, this means changing bad habits for good ones, aiming to eat fresh and clean food, and incorporating more activity into your day in a way that is manageable and sustainable in the long term.

It is important to stress that phentermine is used as an aid for weight loss in obese patients and that relying solely on this medication to make you lose weight will only result in long-term disappointment. Phentermine is prescribed to suppress your appetite on a short-term basis, with three months of continuous use being the maximum advised. It is the patient’s responsibility to use this pill as a tool to help control appetite while following a sensible diet and exercise program. If phentermine is taken without any effort to change the lifestyle in other ways, then it is to be expected that weight gain will occur once the phentermine prescription finishes.

To avoid this, while still taking phentermine, you should build yourself up towards the inevitable end of your prescription by using phentermine as a tool to help you achieve a maintainable healthy lifestyle. As well as eating healthily and exercising, it is important to establish a good sleeping routine and to take time to relax and look after your own well-being and emotional needs in order to create a balanced routine whereby weight loss can be continued or maintained without phentermine. A great way to continue this balanced routine is to use a weight loss supplement such as Phen Caps to manage the end of your phentermine prescription. Like phentermine, Phen Caps suppresses appetite, reduces cravings, and increases energy, meaning that the withdrawal symptoms of fatigue, low mood and weight gain are all less likely. Furthermore, you will benefit from further assistance with weight loss management, therefore extending the likelihood of successfully reaching your weight loss goals following the end of your phentermine prescription.

It is important for patients to take a break from phentermine in order to avoid withdrawal symptoms as much as possible, as well as to ensure that the body is not put under undue pressure while taking phentermine for extended periods. Furthermore, phentermine is intended to be a short-term aid to help obesity, which, if used correctly, should ensure long term weight loss through the incorporation of healthy lifestyle habits. During the phentermine break, doctors are also able to monitor whether patients are able to continue or sustain weight loss without phentermine, which is key for long term success following the end of their phentermine prescription.

Are you on your phentermine break, do you have to take a break soon, or have you taken a break from phentermine recently? If so we’d love to hear from you if you have any feedback or questions, so please comment below!


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73 Responses

  1. I was finally able to get to my goal weight with phentermine and excercise, and kept it there for a year. With menopause the struggle increases and the weight is starting to increase again regardless of a 3-4 day workout and healthy eating. I had few side effects and hoping to renew subscription for 3 months again!

    • I have been off and on phentermine for the past year. It was working very well with me. I lost a total of 20+ pounds. And now I hit a road block. I’m really trying to watch what I eat and stick to a calorie counting diet. A minimum of 1200 calories. I give myself flexibility with it so I do eat up to 1500 calories. I do exercise everyday 3 to 4 times a week. I want to increase that to 5 times a week. Im not loosing weight. I’m taking a break from it right now. I’m just wondering though if I got back on it after my break. Will I loose weight?

  2. I’m coming up soon to my first break. I notice when I miss a dose occasionally I can feel drastic changes in my mood and energy, what should I expect? And where can I get more information on the phen caps?

    • Hi there Lea, Thanks for the comment! Generally speaking, it is best to use this article as a guide regarding what to expect. When it come to medical information, we can not give specific recommendations, as this should only be done by your doctor. If you want to get a more in depth look on how it will effect you, the best suggestion is to speak with your doctor. Also, you can sign up for our weight loss forum, our users discuss all different topics, including the different effects associated with phentermine. You can sign up or check it out by clicking here.

      In regards to Phen Caps, there is a 2-minute you can watch which describes exactly how they help you lose weight – The feedback has been amazing so far! You can check that out by clicking here. To give you a quick brief, Phen Caps are an alternative to phentermine, they can be taken with phentermine for an extra boost, taken after your script has ended in order to maintain your goal weight, or taken completely on their own. They have no side effects and can be bought online, so needles to say, this is a great product!

      Good luck with your weight loss and let us know if you have any other questions! Have a great day!

      Sarah, Phentermine.com

    • Hi lea, this is my second time on phen. I lost 40 lbs my first 4 months!! Great!!! Def changed my eating habits and was jogging everyday! I took a break bad ended up putting 10 back on but prob due to winter and not as active!! Soooo anyway I’ve lost 9lbs my second time and on my last month!! I go to the gym and started weight training to tone and to lose more of my belly it’s helping I am getting smaller! Just don’t get your hopes up!! I don’t feel the same way I did the first time on it but that’s because my body was accustomed to the med but does still help!!

  3. hi I was just wondering if anyone had advise on how to get over a weight loss platou. I lost 15 lbs the first month and 2 lbs the second and I only have 1300 cals a month and workout everyday.

    • Hi there Jamie, thanks for the comment! We actually have an article on the blog here about getting over a weight loss plateau, you can read it by clicking here. Also, if you are looking to boost your weight loss, you could try Phen Caps. They are intended to boost the effects of phentermine, act as an alternative to phentermine or be used on their own for weight loss. You can check out this 2-minute video which explains exactly how Phen Caps help you lose weight by clicking here. I hope this helps, let me know of you need anything else!

      Sally, Phentermine.com

  4. im sorry I meant 1300 cals aday. lol

  5. This is my 3rd month on phen. and I have only lost 10 pounds I don’t feel full even after taking it I feel no different I have had no sided effects but not sure it is working I do excercise daily for at least an hour I eat healthy and have been but not losing any weight any one have any tips to hlep ?
    Please I need help no one seems to listen or they think I am not trying and I am

    • Hi there Shelly, Thanks for the comment! I am sorry to hear about your struggle with your weight loss. Have you spoke to your doctor about your concerns? Generally speaking, this is the best first step in determining if there are any potential issues that are holding you back from losing weight. If you can not determine any specific issue with why your not losing weight, you could try switching up your exercise routine, consuming less calories/changing your diet, or you could look into a weight loss supplement to help boost your weight loss effects. We recommend a product on our website called Phen Caps, it is intended to be taken as an alternative to phentermine or with phentermine, to increase weight loss effects. You can learn more about the product and how it helps you lose weight fast by clicking here. Let me know if this helps and if there is anything else I can do for you! Have a great day and keep up the good work!

      Sally, Phentermine.com

  6. Hey Sally! Am new on here I used to take the
    Phen cap, I did really good on them, I went to a weight loss clinic but was to expense $75.00
    A week was too much for me to pay… Do you know where on line I can buy them? Thank you!

    • Hi there, Thanks for the comment! Phen Caps are a great alternative to phentermine, and often cost much less! You can purchase Phen Caps online by clicking here. I hope this helps, let me know if you need anything else, I am happy to help 🙂

      Sally, Phentermine.com

  7. I have high blood pressure, is this safe for me?

  8. I stopped taking this a week ago after three months. I am so very tired now and my pains that I had before taking this pill have returned. The pain in my joints was there while taking the pills it just didn’t bother me as much. I am continuing my healthy eating and working out. I hope my weight continues to come off but this fatigue is the worse I have felt in years. I called my doctor and was told to have lots of caffeine, not really the response I was looking for considering I haven’t had soda in the last year and do not like energy type drinks.

    • Hey Jennifer,
      That is strange advice from your doctor – while caffeine can give you a boost and help with weight loss and appetite suppression, it often comes in less than healthy energy drinks and soda like you say. In place of caffeine we’d recommend that you take a weight-loss-boosting multivitamin with all the nutrients you need to feel great, and especially one which contains 5-HTP, a serotonin precursor which suppresses appetite, regulates mood and sleep. We recommend Phen Vites by phen.com – https://www.phen.com/phenvites?utm_source=phentermine-blog&utm_medium=reply&utm_campaign=phenvites-page

      Hope that helps!
      Sally, phentermine.com

  9. Hi! I was on Phentermine on and off between December 1, 2013 and November 1, 2014. I lost a total of 79 pounds with the help of Phentermine, eating healthy, and exercising! 🙂 However, I had major surgery on my foot in November of 2014 and am just not starting to be able to be weight bearing on my foot again. Because of the inactivity from the surgery and probably getting off the Phentermine and not making the best food choices I have gained 20 pounds back. I started taking the Phentermine again on January 20th and look forward to being able to start going to the gym again soon as my surgeon allows. I will testify that Phentermine definitely works and absolutely changed my life. Once I lose the 20 pounds post-surgery weight I still have about 50 more pounds to lose to be at my ideal healthy weight. With the help of Phentermine and the new outlook it has helped me have on my life and how I want to live it I know thia weight loss is possible. Altogether I hope to be able to lose 125 pounds and finally believe I can do this. I am 30 years old and want to get my life back, well, the active life I want to live. I just thought I would share this to let people know that Phentermine does work. I did have side effects pretty bad the first month (December 2013) that I took it and it really tested my significant other\’s patience to the extreme to say the least. However, the side effects went away mostly and I got a new attitude and energy for life! 🙂 As I am starting to take the Phentermine ago I have some side effects again but not as drastic as when I first started it the first go around. I will say that having gum to chew on and cold water with me all of the time helped me get through jittery or wired feeling times. I also want to add that I am EXTREMELY sensitive to caffeine, so much so that my doctors have advised against me consuming it, but the way Phentermine makes me feel is not like how caffeine makes me feel. That was something I was really worried about before I started taking it. Anyways, there it is! 🙂 Hopefully I can update this in two or three months with another story of losing weight and gaining life! 🙂 Thank you!

    • Thank you so much for your feedback Emily! We agree that losing weight can be like opening the doors to a new lease of life, as we covered in our blog, Lose Weight With Phentermine, Gain So Much More – https://www.phentermine.com/blog/lose-weight-with-phentermine-gain-much-more/. Weight loss isn’t easy but it is SO worth it! Good luck and congratulations!!
      Sally, phentermine.com

  10. I was on phentermine during 12 weeks, losing around 25lbs (holidays kinda slowed me down). I took a month break and the first 2 days It was so funny to feel hunger and anxiety, as well as a decrease in energy and cardio resistance. However, my body went back to normal immediately, and I continued exercise and healthy eating for 4 weeks (lost 14lbs without phentermine). I took my first 15mg phentermine again today for the 2nd cycle of 12 weeks and I expect it will help a lot during the process of getting rid of my last 60lbs 🙂 maybe I\’ll lose half of it in the second cycle? We\’ll see what happens. But phentermine is awesome in controlling anxiety and hunger and gives me nonstop energy for running!

  11. I have been on Phentermine for a year and lost 33 lbs. I went off of it about a month ago and immediately gained 7 lbs (without changing my eating habits). I am hypothyrioid and I find that the phentermine gives me great energy, clears my foggy-head and helps reduce stress. I am back on it and feel great. I don\’t believe I will be able to come off of phentermine and live a normal life. Without it, I am just too tired, and too depressed. I\’m thrilled to have it – but worried about the long term effects.

    • Hi Nancy,
      I would like to know how do you feel now after tKinh phentrmine as of today 10/4/2107? Are you still taking the pills?

      • Hi yes I totally understand you Nancy I am starting to get really worried now after taking them for 6 months straight I feel exactly the same and like I say though I am really scared about my long term health don\’t know what to do

        • Hi Michelle, we would suggest speaking to your doctor. He or she can work with you to reduce usage and ultimately get off phentermine. You’re wise to be concerned about the long-term effects of staying on this medication and you’re awareness of the issue means that you’re already moving in the right direction. Therefore, we would recommend a doctor’s visit as the next productive step. Best of luck!
          Rachel, phentermine.com

  12. I took adipex for a month I lost fifteen pounds know I’m taking a thirty day brake I plan to do another thirty day trial I plan to lose fifteen more starting July 27,2015 but you have to diet and exercise and when you stop taking them watch what you eat.

  13. Just took a break and re-started and it doesn\’t seem to have any suppressant effect on my appetite anymore. In fact, I feel like it has increased. Has this happened to anyone else?

    • Yep! I was on and off it for a few years, usually buying a month at a time and prolonging it, picking up another months worth every 3 months or so. Well the last two times I\’ve picked some up I consistently took them until they were gone and all of a sudden they just weren\’t effective anymore unless I was on a completely empty stomach, and even still it was pretty weak. Yes, sometimes I feel it even made me want to snack (I\’m sure there is some mind games going on there; I don\’t think the pill actually made me want to eat). In fact, not only did I not feel the effects of appetite suppressant anymore but I actually would feel very dizzy, like my equilibrium was off all the time. That had never happened before in all the previous times taking it. Now, it happens every time. I read that you might be dehydrated or something and to drink more water, so I drank a TON of water while using phen but it didn\’t help. Then I felt I was just taking it because I was addicted to taking the pill, not actually reaping any benefits from it. So, yea, I\’m there. Lol.

  14. I just started phentermine last Saturday and I weighed myself this Saturday. It’s been one week and Ive lost 8 pounds. It’s not a miracle pill, but it helps a lot. I’m eating very few carbs and no sugar. Not exercising at all.

  15. Has anyone ever taken the phen caps? I used the adipex for 12 weeks and lost 55 lbs. Just wondering if it works similar to adipex.

  16. I was on phentermine after a gave birth to my last child I blew up like a balloon, my husband can’t even handle me sitting on his lap. I have tried everything on the market but I haven’t lost a lb. When I was introduced to real phentermine I went from 190lbs to my normal weight of 150. I want to find the real phentermine because they work.

  17. I have never heard about taking a break on phentermine or the scary heart side effects.. I’ve taken very few breaks, (not being able to get to the doc for a couple weeks here and there) but my doctor has filled my script for Topamax (50mg 2xs a day) and Phentermine (37.5mg once a day) for 2 solid years now.. She even upped the dosage of Topamax about 6 months ago, when the weightloss slowed.. Should I be concerned for my health? They say that I can keep taking it as long as my blood pressure looks good, but now I’m starting to doubt how good it actually is for my liver, brain, and other organs? to take a “controlled substance” for this amount of time…I almost feel like I can’t get out of bed without it though. I am also a Hashimotos patient, but am on the correct dosage of thyroid medication. Thank you in advance for any advice!!

    • Hi Nichole,
      It’s surprising when we hear of doctors willing to prescribe phentermine for such a long period of time, especially without breaks. If a patient has a significant amount of weight to lose then it is understandable that they might take phentermine for longer than others, but to be on phentermine and Topomax almost continuously for 2 solid years is worrying. For a start it sounds like you are addicted as you say you feel like you can’t get out of bed without it. Weight management is complicated and with your underactive thyroid taken into account, even more so, but I think that prescribing a medication intended for the ‘short-term management of obesity’ for such a long time isn’t the best way for your doctor to help you. Has she said what her plan is when you do reach your goal weight? And, what if your weight loss slows down again, will she increase your dosage even more? While many medications are taken to control an issue or illness, such as your thyroid meds, phentermine is not something that should be taken in the same way; it’s very much something with an expiry date as it loses a lot of its efficacy over time. I would advise asking your doctor more about how she intends to help you in the future, and also let her know that you feel like you can’t get out of bed without it – perhaps this will make her realize that it might not still be the best choice for you.
      Sally, phentermine.com

  18. My wife has been on Phentermine for several years now. I am worried she is addicted to them. If she misses a day her mood becomes extremely irritable. She has two Doctors because only one will prescribe her Phentermine. She says her Dr. Prescribes the drug as an antidepressant and that being on it keeps her from being suicidal. I don’t know what to believe but I am worried about her long term heart health.

    • Hi Paul,
      I’m really sorry to hear about your wife and the understandable concern you have for her. If she is depressed then there are medications designed to help with this issue, and phentermine isn’t one of them. But, it is addictive, and with what you describe it does sound like she is addicted. You need to persuade her to talk to her main doctor about the possibility that she has depression and also that she is addicted to phentermine, as it seems the other doctor who is prescribing her the phentermine doesn’t have her best interests at heart. Good luck.
      Sally, phentermine.com

  19. I’ve been on phentermine 37.5mg once daily for 9 weeks. The first week was rough: lots of headaches, irritability, with an easily evoked “fight or flight” response. Although I will say that when I was feeling irritable and unreasonably mad, I was well aware of my behavior and knew it was a side effect of the med. I also have underlying mild anxiety/depression which has gotten considerably more challenging on this med. I do take Zoloft 100mg daily. All in all between the weight loss and endorphins from exercising (30 min daily) made it a lot easier to handle. For all of my time on this med, sleeping has been challenging. I have to wait a good 17-18 hrs after taking the med before I can sleep. I tried taking half a pill and it was totally ineffective. I have always been prone to dizzy spells when standing up quickly or squatting and standing: this med intensified that effect big time. But after 4-5 weeks that side effect was much less. Dry mouth is also still very common.I don’t mind as it encourages me to drink more water! All said and done, it’s been 9 weeks and I’ve gone down 37 lbs with little effort, and I still have zero appetite. I eat because I am supposed to, not because I am hungry. The effectiveness has only decreased around 15-16 hrs after taking the pill. I am 31, starting weight 252. I am a huge fan of this med. The side effects are manageable and well worth the 37 lbs loss. Diet wise, I’m doing low carb/low fat/low calorie, I go out to dinner 1-3 times a week and drink minimal to no alcohol. I did not have any spikes in blood pressure either. The initial stimulant effect went away quickly, I just feel like my normal self when I take it. The most important part of this med to me, is that it takes away ALL my cravings. Yes it destroys my appetite, but being hungry was never the reason I overindulged in the past. This med makes food indifferent so I use it as I should – as fuel, not for pleasure. Also you will get a prescription for 3 months as it is intended to be a short term medication due to the side effects on your heart (read packet insert for details). If you have high blood pressure you cannot take this 🙁
    Feel free to ask any questions!
    I am in no way affiliated or endorsed by this med and have posted this review in my own accord.

    • Thank you for your feedback Rico, it’s great to have real insight into what it’s like to take phentermine – the good and the bad – for our other followers. Thanks!
      Sally, phentermine.com

  20. I started taking Phentermine on February 18. A month later, I have gone from 152-139 lbs. I have daily eaten two meals (breakfast and lunch) and a tiny snack in the late afternoon (which mostly I don’t even want) and walked 10,000+ steps daily. (I go everywhere with my pedometer!)) This is the first diet pill I have ever taken and it is fantastic. I have not craved any “bad” foods- no caffeine (coffee or soda), no red meat, no sugar, light on the carbs.
    I didn’t even realize that I was experiencing a side effect until reading this blog. Having written that, one side effect is a bit of a dry mouth, which means I drink more water. The other is my sleep has been interrupted-usually around 3am— but I get back to sleep.
    I cannot believe how much LIGHTER I feel and how much better I feel to be taking my weight control back into my own hands. I am really thankful to have this medication to assist me in changing some poor habits.

    • I just stated taking Phentermine 4 days ago….. I do feel “peppy” when I first take it….but only last few hours. I did have a problem sleeping the second night…didn’t think about Phentermine causing it….as I always tend to have trouble sleeping. I didn’t even think of any side effects til I read this blog…so I can truthfully say…that I am not having any.😄 I would like to loose 60# and was worried that three months would not be long enough so I am very glad to learn of Phen Caps. Can they be punched OTC locally?

  21. I started taking Adipex on February 17, 2016 weighing 259 pounds & at my 1st month weigh-in to get my refill I was down to 233 which is a 26 pound difference, and that was on March 12 I believe. And then for the second month weigh in I just went for I didn’t do as well as the first month but I am down to 218, so that’s 15 pounds lost in the 2nd month for a total of 41 pounds if I did that math correctly! My only concerns about this medication is my eating habits, as I some times do not have the urge to eat at all, as in I physically cannot even force myself to do it. Or the nausea that I get, I noticed it start almost immediately when I started to take Adipex which I know taking this medicine is supposed to be because my doctors think that the benefits outweigh the side effects but I also have no idea if they are just gonna cut me off next month of what my States regulations are on that.

    • Hi Amelia,
      You’ve lost a lot of weight in a short period, and while this is a positive thing in many respects, the fact that you’re sometimes not able to eat is not a good sign. The idea is that phentermine helps you to establish healthy eating habits, but the strong effects aren’t allowing you to do this. As you’re often nauseous or unable to eat anything, it sounds like your dosage is too high for you – a lower dosage or taking half your pill could be a good way to experience reduced effects, and that way you will have the opportunity to adopt healthy eating habits. We would advise you to talk to your doctor and to discuss these issues and see what you be the best for you in order to lose weight and keep it off in the long term. Good luck!
      Sally, phentermine.com

  22. How long should a break be from phentermine ?

    • Hi Edna,
      It’s usually a month but it depends on the doctor and how long he or she wants you to stay off phentermine for.
      Sally, phentermine.com

  23. Hi,
    I started taking adipex a month ago. I was taking them for 6 weeks. I didn’t know about the 12 week cycle, but my prescription was for only 6 weeks. I’ve been off for 2 weeks now and I’d like to start again. Should I wait 2 more weeks, which will equal a month break, or is it OK to start now (after 2 week break) since I didn’t take adipex for the 12 week cycle.

    Thank you,

    Mikea B.

    • Hi Mikea,
      The 12-week cycle is a recommendation more than a strict guide, as is the month-long break. So, it would be fine to start taking phentermine again after a break of two weeks, especially as, like you say, you haven’t actually completed a 12-week cycle.
      Sally, phentermine.com

  24. I have been on phentermine for almost a month. My period has been on for two weeks now. Should I take a break from the pill or should I keep pushing through? Sincerely a girl that wants to feel normal again.

    • Hi Mia,
      With medical concerns like this it’s best to ask your doctor as we wouldn’t want to advise you either way. However, you shouldn’t take a break from phentermine without first consulting your doctor.
      Sally, phentermine.com

  25. I have been under 18 months of treatment with a schedule of taking Phentermine for 30 to 60 day periods followed by 60 to 90 day breaks from the drug. During this time I lost almost 70 lbs and my waist went from a 46 to a 36 !. I and My Doc found that after a 50 lb loss the steepness of the loss slowed as my body adapted to not so much the drug but the reduced calorie intake at 950-1100 per day. I have been using a high -low intake pattern day 1 1200 to 1500 K intake then day 2 a 700K intake where the body burns at the 1500 K rate..
    I still want to reduce an additional 20 lbs and now only use the meds for 30 days out of 120 overall days with a 90 day off. The next phase will increase the period to 180 days with 30 days of meds. This schedule we designed to physically diminish drug dependence and to help as a long term maintenance program With the bodys adaptation to the new life style at 50 lb loss level, the weight loss slows and plateaus are common. The use of the drug at increasing intervals ( as mentioned) allows for periodic movement from one weight plateau to the next lower one till a target weight is achieved . When target weight is achieved all meds will cease. However I will plan for the next year to continue medical consult and support.

    • Dan: The method of eating different calorie amounts is very effective and used by most body builders during their reduce phase. When I was doing it 20 years ago I’d have 3 “low carb” days, where I would eat 4 meals, a fruit, a yogurt and only include certain complex carbs (oatmeal, sweet potato, or barley) at meal 1 and 3. On day 4 I’d have a “high carb” day and would include the healthy carb and exclude the veggies at meal 2 and 3, and then have the veggies and carb with my protein at meal 4. It works great!

  26. I started it Sept 11 and lost 12lbs so far…it helps my IBS so much! It has slowed the digestion down to normal. I want to be on at least half for life! Going to ask Dr in Dec!

  27. hi phentermine worked for me and then it completely stopped. My body built a tolerance to it. It just stopped. Naturally I’ve gained the weight and havent taken it for 3 years. Will it work for me now or will it never work again? Please help. I dont want to go and waste time and money and have it not work again.


    • Hi Brenda,
      After 3 years without phentermine it’s likely that you will feel the effects of it again if you start a new prescription. So, it shouldn’t be a waste of time to take phentermine again. However, what does concern me is that you say, ‘Naturally I gained the weight back’. Phentermine is designed to be taken for a limited period but to enable people to make permanent lifestyle changes. This article has some advice for those taking phentermine after previously taking it before: https://www.phentermine.com/blog/second-third-fourth-time-around-phentermine/ and this article has some tips for how to not gain the weight back after phentermine: https://www.phentermine.com/blog/not-gain-weight-phentermine/
      Hope that helps!
      Sally, phentermine.com

  28. I started phentermine in August. I loving running and hit a plateau on weight loss. I lost about 30lbs in 5 months. I weighed 151 at 5’1, now I’m 128. I feel great! I have only had it filled 3 times. What I started doing was taking it half the week. M-thurs. Then I had my cheat days on weekends. I think that worked best for me. That helped so I won’t build a tolerance for it. I still have about 3 wk supply and it works for me. It’s not as intense as 1st month, but I still have the boost of energy and no hunger. On the days I don’t take it I feel the same. But on my “cheat days” I don’t eat a lot. I get full fast. Hope that helps.

  29. As a former body builder, I know how and what to eat. Over the years I just got lazy about my diet and ate too much and the wrong things. I finally committed to getting 40 pounds off (maybe a bit more) and began using Phentermine on 12/26 thanks to a friend who had a script for it. I have been on a VLCD (500ish calories/day) and lost 18 pounds this first month. I had one “cheat meal” where I drank about 2/3 bottle of red wine, a small salad, and 5 barely breaded chicken wings with only hot sauce. I did NOT weigh myself the following morning, but got right back on the wagon. The following day the scale showed me up 1/2 pound from 2 days earlier, and the following day 2 1/2 pounds lower than 3 days earlier, which meant I was down 2 pounds from the weight of the day I cheated.

    I went to my doc to get a script from her and she took my BP and made me do an EKG to be sure I was healthy, which I was. She only gave me a 30 day script this week also told me the effects will decrease so maybe I should take it during the week and get off it on the weekends, which I will do this coming weekend. I didn’t take it yesterday to see and, aside from being a bit tired, I felt totally fine. I suspect different people will have different reactions as people have mentioned above.

    The bottom line is that when I up my calorie content and begin exercising formally again I will go to 1500 cal/day and go back to 3 meals/day and include the healthy fats I have always used (coconut and avocado oils and some olive oil). I will avoid sugar and carby foods until my body gets used to eating normally again.

  30. I just started taking this. It has only been 3 days. I’ve noticed I’ve been experiencing acid reflux. Is this common and will lessen in time or should I stop immediately?

    • Hi Amy,
      Acid reflux isn’t a side effect of phentermine so it’s more likely that it’s related to your diet or eating habits. To avoid acid reflux, try to eat smaller meals, avoid eating less than 3 hours before bed, and don’t lie down after a meal either. Smoking as well as certain foods can aggravate the symptoms, so you might want to avoid citrus fruits, tomatoes, chocolate, mint, garlic, onions, and spicy food, and drinks such as tea, coffee, soda and alcohol.
      Sally, phentermine.com

    • Amy,
      Phentermine aggressively makes my acid reflux worse. I take omeprazole (Prilosec) 20mg twice a day, or it will get so bad that it makes my throat very sore, and make it feel like there\’s something stuck in my throat.
      I didn\’t even know I had acid reflux until I started taking phentermine, but taking the acid reducer medication offsets it.

  31. I don\’t understand why people are still looking for the miracle diet pill 💊 when it was introduced to us in 1959. I had an amazing experience with Phentermine reaching my target weight soon and looking forward to maintaining my newly discovered self. I just hope Phen caps help me out just as well. Good luck to you all! Happy weight loss!!

  32. The first round of phentermine was 5 weeks. I took a 3 week break. I lost 25 lbs and maintained it during my break. I went back on phentermine for 4 weeks, took a 3 week break. I lost another 20 lbs and maintained it during my break. I just started round three. Its been a week and I lost 5 lbs.

    I am counting calories and i realized I over ate my entire life. I am a naturally active person, but I have found my weight is only controlled by how much I eat. I have worked out a lot and never lost weight.

    I had borderline high blood pressure when i started and the lost weight has lowered my blood pressure to a normal range.

    Really, i still have 70 lbs to lose to get to my recommend weight….but i would be happy if i lost another 30.

    I did have some side effects like constipation and difficulty sleeping… but the positive out weighs the negative for me. Phentermine is a wonderful tool if you use it correctly.

  33. 5\’5 woman with a starting weight of 219 lbs. Down to 185 lbs in 3 months. I exercise 3x a week and follow Weight Watchers. I\’ve done WW multiple times over the last 10 years with much success but thanks to my insane appetite and cravings I tend to back slide and gain the weight back. Each time I\’ve tried to lose weight it has been more miserable then the last time. In a moment of desperation and as a last ditch effort I joined a Weight Loss Center and the Dr. prescribed these pills. I\’m pretty anti-med but I was desperate and gave it a try. It has been life changing! For the first time in my life I feel like I can control my cravings and food does NOT control me which makes eating healthy and exercising so much easier. The first month of side effects were less then ideal but the weight loss has made it worth it. Now I feel \”normal\” with minimal side effects and will likely stop taking them soon. Yes, phentermine has a lot of scary side effects but so does being obese. Obesity can cause a whole host of health issues so I figured I would pick my poison so to speak and i\’m glad I did. It has been life changing.

    • Hi Mel. Congratulations on all of your success with phentermine! If you’re interested in helping motivate/inspire others, we’d love to hear your story in the success stories section of our site. Best of luck in your continued journey!
      Rachel, phentermine.com

  34. I started the 15mg dose in November, moved to the 37.5mg in February. Total weight loss 60lbs. I am working on my last 10-15lbs and am only using half of a 37.5 per day now. The full 37.5mg made me anxious and short tempered. I really had and still do have to keep myself in check.
    I eat 1300-1500 calories per day and work out 2-4 times a week and aim for 10,000 steps per day. I do get dry mouth, which just makes me drink more water.
    I think I am ready to stop and will discuss with my dr at my next appt. It really helped me go from 250lbs to 190lbs when I couldn\’t seem to lose even 5lbs before taking it. I worked hard and I am at a plateau right now as I really want to shed that last 10-15lbs. Everyone comments on how much weight I have lost but all I can see is I can\’t lose that last 10-15lbs. As I get toward what I feel should be the end of my Phentermine journey I have been slacking on \”working out\” but I am still very active. I have change my lifestyle for good.
    Even if I don\’t make my goal weight I am healthier and look and feel better than I have in 20 years. I just have to remind myself that I LOST 60 POUNDS!!!! Thank you.

  35. Do you recommend someone using this for 6 years straight?

    • Hi Lauren! No, not typically. Phentermine is generally recommended for short-term use only (about 12 weeks). As we describe above, most doctors advise a break of at least one month after each three-month cycle, and may then prescribe phentermine for a further 12-week period if it is deemed necessary. The time limit recommendation is related to the addictive nature of phentermine and potential for side effects. However, it’s also not recommended to abruptly stop phentermine – especially if you’ve been on it for a long time or with a high dose. Please speak directly with your prescribing doctor if you are concerned that you may need a break from phentermine.
      Rachel, phentermine.com

  36. Hi everyone;
    i was on adipex for 12 months. On 3 months off 3 months,
    After a total of 12 months I lost 101 lbs. I never noticed any side effects.
    Now after 1 1/2 yrs i have gained 50 lbs back due to a lot of stress.
    Now i will start again to get off the 50lbs…

  37. Is anyone else on zoloft(setraline) along with phentermine,
    I have been on zoloft for about 20 years and recently began phentermine I lost 25# in 4 weeks and feel great,
    Also has anyone taken phen caps with the phentermine.?
    If so did it help suspress your appetite more?

  38. I have lost over 60 lbs since on this medication for the past 8 weeks. The side effects are manageable and worth the results. I do work out three times a week at least, for about 30 minutes of jogging and 30 minutes of weights and stretching. The deit is the most important, I eat 800- 1,000 calories per day, I found it I eat more then 1,000 calories my weight loss greatly slows. At first it looked crazy and unaptanable but I eat what I want but very little of it. I make sure to eat a lean high protein shake for lunch and high energy foods as much as I can. I give myself one cheat day of 1,400 calories on Sunday. It makes eating a restricted deit doable. I eat lots of protein and stay with water, except on Sunday I have ONE cherry soda 12oz. I calorie count and drink coffee with almond milk and stevia or water. Be careful with caffeine while on this, only drink a small cup of any caffeine product a day or you will regret it. The medication helps this greatly and I am worried if I will be able to do this so easily once with out the aid of the medication. I hope what has worked for me, may be able to help someone eles. The big thing is the work outs keep you healthy but the very low calories is where the weight loss is and the key. As adults we eat way way too much and are lied to about how much we should eat. Try not to eat sugar, drink water and don\’t eat more then 1,000 calories, if your obese and trying to lose weight. I found out as an adult we really don\’t need to eat as much as we think we do. I started on this weighing over 300 lbs. I have lost over 60 and I am two sizes down in clothes. I have another 60 to go, but I NEVER thought I would be here in I weeks. Good luck to everyone on their weight loss journey.

    • Thank you so much for sharing your story, Jopanda! And we wish you the best of luck on reaching your weight loss goals! You can do it!

  39. i took phentrimine 37.5 mg for about 7 yrs no break of course i lost weight at first very fast but it stopped and i actually gained weight. i know that is a very long time to take that. well after a few years my blood pressure did rise alot. well 2 months ago i stopped taking them. i got diagnosed type 2 diabetic and only take 1 metfomin daily and i feel i have t eat so much to keep my blood sugar high enough to do anything without it dropping. anyways my question is my dr said i can try to control my blood sugar without the meds. but was wondering if phentrimine can give me a jump start again to lose weight but im scared now cause my diabetes. is it safe to take with metformin or is it best to not take the met and try just with the phen. i need to lose weight but now i see there is no benefit long term

    • Hi Char!

      You really need to ask your doctor or primary care physician; they are the only ones who are qualified to give you the best response. There ARE doctors who prescribe both (Metformin and phentermine) because they tend to improve the weight loss effect but this combination would have to be SPECIFICALLY approved by your doctor.

      In any case, remember that weight loss aids such as these are just meant to train your body and mind for a better, healthier lifestyle. It’s up to you to make permanent changes to nutrition and exercise so the weight loss can be long-term, or at least so you don’t regain all the weight lost!

      Best of luck,


  40. I see this is a really old thread but I\’m going to post anyway…
    I was on phentermine (duromine) for a few stretches to get rid of pregnancy weight that I was battling to lose after baby was born , and my mind was like a machine on this drug! I felt like a normal person with focus and clarity and my productivity skyrocketed.
    I needed less sleep and when I woke up in the morning I was refreshed. It\’s such a pity that it can\’t be taken as a long term drug coz I would\’ve been happy to be on it purely for the mental clarity and focus that I achieved while on it.
    Oh and I lost all the excess weight too lol!

  41. Old thread, but anyway.. I’ve been on 15mg Phentermine for 7 months, I’ve lost nearly 40lbs and have hit a plateau. I will purchase Phen Caps right now and will taper off the Phentermine because suddenly I’m worried about withdrawal. My brain is lucid, I have energy and don’t seem to need much sleep. Today is my first day not taking it, it’s 9pm and I feel awful, I’m also a little under the weather so who knows which is to blame. I will say that my brain often tells me the following: You won’t get much sleep tonight but that’s okay, you’ll be fine a few minutes after you take Phentermine. My doctor wasn’t concerned about me staying on it for so long, but she is cutting me off next month. I’ve had no side effects and can’t believe I’ve lost so much weight. My eating habits have changed drastically. I’m worried to take a break, but I think I’ll break for a month or two and then go back on for 12 week periods until I reach my goal. Wish me luck!

  42. I started taking 30mg Phentermine 10 days ago 236lbs; now I’m 227. Almost 1lb a day. Now here’s what I’m doing:
    200 calories porridge for breakfast
    400 calories low fat low carb lunch, (varies but never more than 400)
    150 calorie snack in the evening (forced down)
    6-8x 30ml espresso coffees throughout and the day minimum (1 flat teaspoon of sugar in each coffee)
    Half a gallon of water throughout the day minimum.
    1 hour excersise every day alternate cable weights, power walking 4.5 miles, jogging and 5 a side indoor soccer.
    Day 1 and 2 I can’t even describe how dry my mouth was; I drank about a gallon of water (no exaggeration) mouth was still dry!!!
    First few days had a ‘smoke’ before bed (2200) to encourage sleep but wide awake at 0300 every morning so far but have so much energy it doesn’t really become an issue.
    No anxiety, occasional mood swings; I mean a conversation can make me see red and literally scream then moments later I’m all like sorry guys…… Mouth been fine since day 3, I take the pill every morning 45 mins after porridge around 0930 but day 11 I’m going to take on an empty stomach around 0700 in the hope of getting a long nights sleep (not that I need it, just had 10 days of 4 hours a night, as it takes around an hour to get to sleep once lying down) Headaches like my mother in law has a voodoo doll first 3 days despite drinking so much water I went over a gallon on day two. I cannot stress how much energy I have during the day. Yes I still yawn throughout the day as anyone would but never EVER feel tired.
    So I’m going to take them daily for a total of 20 days and hit you back with an update.
    40 year old male 5 foot 10
    Peace out!!!!

  43. I have been on phentermine 30 mg since 2012, with no breaks the last two years or so. I have developed an irregular heart rhythm… but nothing the cardiologist is concerned about. I want to take a break for a few weeks and start working out and eating healthier. My question is if I want to go back on in a month or so would that be ok?

    • Hi Lysa! Your medical team (doctors) would be the best people to ask about this. They are familiar with your specific case and history and will be able to best assess if going back on phentermine after a break is a wise decision for you.
      Rachel, phentermine.com

  44. I recently had been on Phentermine to help in my weight loss goals. I recently suffered a ministroke and was advised by the hospital doctor to stop taking Phentermine.

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