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You NEED To Know: Phentermine and Alcohol


Most of us like to relax with a cold beer or a glass of wine after a hectic week, but then we also know how alcohol isn’t great for our health. When you’re aiming to lose weight, alcohol is often best avoided due to the number of calories it contains and the effects it has on the body, but for those taking phentermine there are further risks to consider. Here we explain how alcohol hinders your best weight loss efforts and why it is inadvisable to mix phentermine and alcohol, with respect to both the success of your weight loss journey and to your health.

 How Alcohol Effects Weight Loss

The bottom line is, alcohol and weight loss really don’t mix. There are several ways in which alcohol negatively effects the chance of success on your weight loss journey. Firstly, alcohol contains many empty calories, meaning it is high in sugars which get converted to fat without providing the body with any nutrition. Secondly, alcohol decreases testosterone levels and causes fluid loss and tiredness, meaning exercise is more difficult and less effective. As a depressant it also suppresses the functions of the liver for as long as three days following the consumption of alcohol, meaning it limits your body’s ability to burn fat and build muscle by stopping the liver from processing food into energy. Lastly, alcohol leads to poor food choices as it activates hunger messages in the brain, leading to cravings for unhealthy foods high in saturated fat and salt.

Keep reading to learn more about phentermine and alcohol, or check out this infographic if you’re in a hurry!

The Interaction between Alcohol and Phentermine

For those taking phentermine to lose weight, as well as the effects of alcohol on weight loss, there is the additional reaction between phentermine and alcohol to consider, which comes with risks to health and potentially dangerous side effects. The problem with combining alcohol and phentermine arises from the fact that phentermine is a stimulant while alcohol is a depressant. Phentermine works as a weight loss medication because it directly affects the central nervous system by suppressing the parts of the brain responsible for appetite control, while other functions are stimulated to enhance energy and tolerance to intensive exercise. By contrast, alcohol suppresses the main functions of the central nervous system. The mechanisms of phentermine and alcohol are different, so simultaneous consumption of these can result in a negative drug interaction.

Warnings about drinking alcohol while taking phentermine explain that the combination can increase the risk of cardiovascular side effects, such as increased heart rate, chest pain or changes to blood pressure. You may also be more likely to experience symptoms such as dizziness, drowsiness, depression and difficulty concentrating. Some of the side effects that those taking phentermine have mentioned in the Phentermine.com support group on Facebook include: jittery feelings, an inability to concentrate or interact in conversations, feeling on edge, and enhanced anger.

In addition to these negative side effects, alcohol also makes phentermine less effective, as one of the Facebook users mentioned in the link above. Alcohol activates hunger and greatly limits the effectiveness of the phentermine by reducing the appetite suppressing effects that phentermine has on the brain, while also decreasing the energy boost that phentermine supplies. Alcohol also effects the pH balance of the body, making it more acidic; phentermine has been shown to last longer in the body by as much as twice as long when the pH balance is more alkaline, which can be achieved by eating lots of fresh fruit and vegetables, while refraining from unhealthy acidifying foods and drinks like ice cream, butter, coffee and alcohol.


Can I Drink Alcohol While Taking Phentermine?

It’s best to refrain from drinking alcohol while taking phentermine, or at least to limit the amount of alcohol you consume. Your doctor will explain to you what you should and shouldn’t do while taking phentermine, including your recommended maximum intake of alcohol. To ensure that you are more aware of how alcohol affects your body when you begin taking phentermine, you should aim to drink slower and to alternate alcoholic drinks with glasses of water to keep yourself hydrated and to give the alcohol time to enter your body so you can monitor how you feel. If you begin to feel unwell or experience symptoms such as those mentioned above, you should stop drinking alcohol immediately.

While it is true that some people experience no adverse side effects from mixing alcohol and phentermine, it is something that everyone should approach with caution, as when taking individual differences into account, this kind of drug interaction can be very dangerous for some people. Much of the success you will gain from your weight loss journey is related to knowing your body and acting in a way that you know is right for your health and well being. This means avoiding or at least limiting your alcohol intake so as not to experience these negative side effects when mixing alcohol with phentermine, as well as in order to enjoy a healthier lifestyle in the long term.

80 thoughts on “You NEED To Know: Phentermine and Alcohol”

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      There’s no good way to tell your wife she’s crazy. You might want to consider calling her doctor and voicing your concerns. He will probably live if he tells her instead of you.

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    My doc just prescribed phentermine 37.5 for me for a month to assist with the 35pds I put on over last 8 mths. Healthy other than arthritis issues which I see Rheumatologist for. I joined a cardio work out program to go 2x week which I start Thurs. I am sometimes sensitive to meds so I’m careful, such as benadryl I’m very allergic to but can take over counter cold meds. Question is….starting this new med phentermine and one of the side effects is heart rate increase am I ok to take it and go do my cardio work out? Is it going to be to much? They do monitor my heart rate at the gym im going to during the hour work out. I really want this to work and can handle most side effects listed but don’t want any heart issues. Im 44 yr old woman who eats mostly healthy just getting older and can’t keep weight off like I use to. Goal is 30 lbs in 3 mths. Only taking this med for a month.

    1. Sally

      Hi Laura,
      An increase in heart rate is a common side effect but nothing to worry about, and the majority of phentermine users do some kind of cardio while taking the medication. We would advise you to start the workout program but to be conscious of your heart rate and stop if at any point you feel discomfort or pain, especially in the chest.
      Sally, phentermine.com

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    Dear Concerned Husband:
    OMG!!! I totally agree!!!! I have a very dear friend who has been taking it for over a year now and it is making her totally crazy!! She has these intense anger outbursts that are demonic!! I don’t even know who she is anymore. It’s so sad because I’ve known her for 30 years and now she’s become the spawn of Satan.
    The anger outbursts are more intense when she has a few alcoholic beverages while taking the phentermine!

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    I can usually drink and I can drink, well I started taking these two medications about three weeks ago I lost seven pounds, however, we have gone out twice, I have had three drinks while we were out. The first night I passed out at the bar, he had to carry me home and into the cab, and the second night I was out like a light! I do not remember anything I only had three jack and cokes, and believe me I can usually put them down !! These drugs and drinking are very dangerous, I will not be drinking and taking these meds ever again !!!! Thank god I’m alive, I fell flat on my face in the bar, blacked out and that is not like me at all !! very scary!

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      This happened to me this weekend! I am down 25 lbs and I take the 37.5 pill in the AM. This weekend I had a few captain cokes and I totally blacked out. I don’t remember a thing, I woke up in the hospital. I will not ever drink again while on this mediation.

      1. Sally

        Hi Joanna,
        Thanks for sharing your experience with us. We try to err on the side of caution when advising our readers about mixing alcohol with phentermine, but we’re sorry to hear that you had such a strong reaction. We hope that our other readers bear this in mind and take precautions when mixing the two.
        Sally, phentermine.com

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    I’ve just started Phentermine 30mg and it’s already amazing for my appetite suppression. The only issue I have is that I’m craving cigarettes and alcohol! I used to be a methamphetamine user so I think the Phentermine is giving my brain that same trigger. I feel completely fine after a few beers; I’m just worried the calories from the beer will hinder my weight loss. I’m not usually a big drinker anyway, but it’s been a few beers every night lately. I’m living off beer and steamed veg lol

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      It’s been a couple of months now. How are your results? I just got my prescription today and it’s for 30 mg. Also, I’m curious to see how I do if I have a couple of cocktails while taking them.

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    Omg!!! I have been taking it for 2 days…it’s great and I’m not hungry but do try to put some healthy food in my body… I need to lose 50kg…back injury…all a bit of a nightmare… But I have to admit I do suffer anxiety… Depression and I’ve used alcohol for a very long time to self medicate …25 Years… From the generation of binge drinkers!!! I am realising… Slowly …2 days …and yes I’ve been drinking… That I’m not getting the buzz I’d usually get!!! So I need to get it out of my life…its very hard…but alcohol is the reason I gave the typically fat around the middle . I’m 47 on Monday and shit I need a wake up call…yes I’m a mess ha ha…constructive feedback only please 🙂

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      I can relate completely. Same age as well.
      Can you tell me if you are still doing this medicine. I’m thinking of trying it out and wanted to know how it’s going. Thanks


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    Janet – I hear you! You aren’t alone. I like a daily drink. Or two and while I lost the first week to 2, nothing since then. I know it’s a crutch, a habit, my signal to relax and that I really will do much better in many ways to eliminate it, but it’s harder than dieting. Going to give myself Friday & Saturday and see if I can’t gain some control during the week. I always felt one isn’t hurting. I have to think hard how I want to lose the weight, and I can go back to an occasional cocktail. I’m sabotaging myself. Good luck to you.

    1. Sally

      Hi Ainka,
      It’s fine to have the odd glass of wine, although it’s important to bear in mind that alcohol does slow down the liver for several days, meaning your weight loss might stall as a result. Phentermine stays in your system for up to 72 hours but if you’re just having one glass of wine then there’s no need to stop taking phentermine. Just let a trusted friend know that you might have a different reaction to normal and remember to keep hydrated by drinking water at the same time.
      Sally, phentermine.

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    I’ve been taking phentermine 37.5 for around a week and with the exception of the first day or two of feeling a tad jittery/more energized I feel like I haven’t experienced any side effects whatsoever and I was worried about taking it beforehand. I’m 27 years old, 6ft and 200lb – I just wanted to drop about 20 lbs or so. Anyway, things are going fine but I have a bachelor party trip coming up in a couple days and I haven’t drunk since being on phentermine. I’ve read what others have said about being careful taking phentermine when drinking. But this is my best friend and we will be drinking quite a bit (nothing crazy but more than normal obviously).

    We will arrive Thursday afternoon and come home Sunday morning.

    I haven’t missed a day since I started taking phentermine like 8 days ago or so. My plan is to take it tomorrow (Wednesday) and then not take another one until Monday when I get back home to get back on my regular schedule.

    If I stop taking it should I be okay on the alcohol front?

    Side note – for the past month prior to taking the phentermine I had been having chest pains/tighteness on my upper left side (not sure why) for about a month. After taking phentermine I haven’t really had chest issues in a week.

    Thanks for any responses.

    1. Sally

      Hi Jon,
      It’s probably too late to advise you to not take the phentermine today, but just so you are aware, phentermine can stay in the system for up to 72 hours so it could be a good idea for you to take it a little slower on the alcohol front on the first day (Thursday) and see how you feel. Let a more reliable friend know and ask him to keep an eye on you. Try to drink water throughout the day/night as well and remember to eat something filling before you start drinking heavily – dairy products like yogurt are also good for lining your stomach before drinking.
      Have fun!
      Sally, phentermine.com

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        Hey Sally, after I wrote that I seen where you said phentermine stays in your system 72 hours so I didn’t take it today and won’t be. Just want to be careful. Thursday (tomorrow night). Will be the first night of the trip where we go out. I’ll try and take it slow that night for sure.

        1. Sally

          Hi Jon,
          That’s great, it’s better to be on the safe side definitely. Hope you have a great weekend!
          Sally, phentermine.com

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          How were you on your bachelors weekend as I am going to a mates bday party in a couple of days and want to know if you had any bad reaction cheers.

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    Love the reviews. Just started my journey today with the pills. Craving a glass of red wine. Smoking cigarettes like crazy. I feel real jittery 2. What now? Hopefully my weight loss…good luck everyone.

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    I’m afraid my experience of phen has ended abruptly. Palpitations, waking up sweating in middle of night and a crushing sensation in the middle of my chest like an air bubble you can’t get rid of with a burp. The first time this happened I drank 2 large glasses of wine. Stupid and Scary. Have also had an impending sense of doom and depression like nothing I’ve ever known. I am guessing I have a condition I wasn’t previously aware of. Off to docs to find out. Please be careful everyone. Even if this is nothing, the side effects have been so nasty I won’t be using phen to sort my weight out.

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    I’m going on a family cruise in 6 days. Um not a heavy drinker but I plan on having a few frozen alcohol drinks. When should I stop taking phentermine to be able to enjoy my drinks without worrying?

    1. Sally

      Hi Dee,
      Phentermine can stay in your system for up to 72 hours, so if you want to be sure that there is no phentermine in your body then you should probably stop taking phentermine 2 or 3 days before you leave. Have fun on your cruise!
      Sally, phentermine.com

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    I have been taking this medicine since 1/4/17 and I didn’t have any serious side effects. I’m taking 37.5mg and I only have a burst of energy all day and find it hard to fall asleep at night. I have craved a glass of wine but I’m willing to fight that craving to see the full impact of the meds mixed with healthy foods and cardio. Good luck everyone and I will update after 15 days to say how much weight lost. Oh I am 5ft 175lbs starting out so I will weigh myself soon to see the results.

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    I am here because I started phentramine two days ago. Tonight is my regular girls night out when we go sing karaoke in our local pub. I took my phen at 8 am. I want to know if 2 beers are ok to have around 10/11pm?
    Also, the only side effect I’ve had is one that I occasionally suffer from anyhow. Palpitations; usually when I’m stressed out I’ll have some, when the stress leaves so do the palpitations. Now, I’ve had a lot of energy the last couple days and I cleaned my entire house very quickly today and as of 2:30 pm had not eaten… I had forgot! I realized I’d been on the move for a while, sat down to relax and felt better. I can say it definitely curbs my appetite. I’m not hungry at all. Doc put me on for 30 days then I’ll recheck to get w him. Inneee to get a jumpstart on some wieght loss but shooting for 20 this month alone… per doc. Anyhow, still debating the beers. I like to be cautious.

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      Hi Dori. Thank you for reaching out.Alcohol can slow down weight loss, and can also inhibit the effects of phentermine, plus the combination of phentermine and alcohol can cause you to feel the effects of the alcohol much quicker, so it’s best to avoid alcohol while you’re taking it. However, if you just want to have a drink or two for a special occasion then this is unlikely to cause you any problems – just be sure to drink water throughout the night and ask a trusted friend to keep an eye on you.

      You are welcome to join our brand new support group so you can connect with other phentermine users, share your experience and get some valuable advice. https://www.facebook.com/groups/1069871763087734/

      Have a nice day!
      Rebeca, phentermine.com

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    Can a person with fatty liver and a leaking heart vault take 15mg Phentermine? That’s my situation and I can’t lose weight. Thank you for your advice in advance

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    I was 5′ 7″ and 200 lbs. when I started Phen on Jan 17, 2017, I am now (March 17, 2017) at 185 lbs. (This is the ONLY thing that has ever worked for me)
    I drink 1-2 glasses of wine 4-5 times per week, it seems the Phen makes me crave wine, and I started working out 3 times per week. I have noticed the weight is coming off MUCH slower since drinking the wine and I have an occasional head ache the next morning. I only take 1/2 of the prescribed 37.5 pill. I have noticed my blood pressure has gone up from 110/65 to 128/90! I am wondering if I should stop taking the meds because of my blood pressure.

    1. Sally

      Hi Myra,
      If your increase in blood pressure is a concern then you should speak to your doctor to see if he or she agrees with you coming off phentermine. However, drinking wine most nights definitely sounds like something you need to stop or at least reduce for the sake of your health and your weight.
      Sally, phentermine.com

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    I’ve only been taking phentermine for a couple of days now. We are going out tomorrow night. I took a pill at like 7 this morning and was going to skip my dose tomorrow to make sure I don’t have any interactions. I know for weight loss reasons, that’s not the best route. But it’s my birthday, so I’m making an exception. Just want to err on the side of safety! Will the phentermine be out of my system enough by tomorrow night to enjoy a night out?

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      Phentermine should be out of your system after 3 to 5 days. Drinking alcohol can increase certain side effects, so if you were thinking about indulging in some of that, it is best to cut down or exclude alcohol from your diet while you are taking phentermine. Phentermine may also impair your thinking or reactions, so be careful if you drive or do anything which requires you to be alert! During the first few days of phentermine it’s advisable to monitor how you feel in order to self-assess how the medication is affecting your body. If you feel uncertain about taking on certain tasks, seek advice from your doctor if you need further reassurance.
      In the meanwhile, be sure to drink lots of water, and let friends and family know that you’re taking the medicine so they can help you out in case you start to feel different during your celebration.
      Oh, and happy birthday!



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    Should I be concerned if this medication actually give me more patience and keeps me in a better mood ?

    1. Avatar

      Hi Massiel!

      We definitely recommend you consult your doctor if you are experiencing changes or side effects, including positive ones such as these.

      You could also visit our user support page on Facebook and share experiences with fellow phentermine users.



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