Why You NEED To Take a Break from Phentermine

Why You NEED To Take a Break from Phentermine

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.


Take a Break. Lose Weight.

Phen Caps is recommended by over 30,000 people like you who want to lose weight fast and effectively.

  • No Prescription Required.
  • No Side Effects.
  • Made in USA.

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.

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 due to 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 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 Affects 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 (noradrenaline).

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 use of many drugs causes adaptation within the body that tends to lessen the drug’s original effects over time, known as drug tolerance.

Many phentermine users experience a reduction in the 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.

The Importance of Taking a Break

How Phentermine Affects the Body

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 that 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.


Continue Losing Weight.

Phen Caps is recommended by over 30,000 people like you who want to lose weight fast and effectively once their phentermine prescription ends.

  • No Prescription Required.
  • No Side Effects.
  • Made in USA.

It is important to stress that phentermine is used to aid 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 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 suppress appetite, reduce cravings, and increase 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 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 by incorporating healthy lifestyle habits.

During the phentermine break, doctors can also monitor whether patients can 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!

Similar Posts

Leave a Reply to Stephanie Butenhof Cancel reply

Your email address will not be published. Required fields are marked *


  1. 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!

  2. 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

    1. 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,


  3. 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.

    1. 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!

  4. 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?

  5. 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…

    1. 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

  6. 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.

  7. 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.

    1. 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

  8. 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.

  9. 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!!

  10. 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?

    1. 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

    2. 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.

  11. 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.

  12. 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.

  13. 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.


  14. 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!

  15. 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.

    1. 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!

  16. 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.

    1. 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

  17. 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.

    1. 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

    1. 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

  18. 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.

    1. 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