The Truth About Taking Water Pills On Phentermine

The Truth About Taking Water Pills On Phentermine

Many people losing weight with phentermine search for ways to increase their weight loss potential by adding supplements like PhenQ, 5-HTP, and B12 injections to their daily dose of phentermine.

Worryingly, it is also becoming more common for phentermine users to take water pills alongside their phentermine prescription, thinking that this will increase weight loss.

Here we explain why water pills should not be used for weight loss purposes and why it could be very dangerous to combine water pills with phentermine.

What Are Water Pills?

Water pills, known formally as diuretics, pressure your kidneys to flush out unnecessary water and salt from the body through urine.

One of the most commonly prescribed medications, doctors usually give diuretics to people whose bodies cannot regulate fluid intake.

Getting rid of excess salt and fluid helps to lower blood pressure and can make it easier for the heart to pump.

So, water pills are often prescribed to patients with heart-related health issues like hypertension, heart disease, and heart failure, as well as other conditions such as liver problems and glaucoma.

Can Water Pills Help Weight Loss?

Can Water Pills Help Weight Loss?

In a word, no.

Despite the commercials you might have seen promoting water pills as a quick slimming solution, they should never be prescribed to people looking to lose weight and keep it off because diuretics do not affect body fat.

The effect produced by water pills is a classic example of how the scale does not represent the whole picture regarding weight loss.

While it is true that diuretics will flush out water from the body and could lead to a lower scale reading, this effect is temporary and not an indicator of weight loss.

This is because as soon as you stop taking the water pills, your kidneys will go back to absorbing the right amount of water and salt for your body, causing the scale to show your true weight again.

Motivated by a desire to see a lower number on the scale, some people choose to take over-the-counter (OTC) water pills as a means to reduce bloating and drop water weight.

It is important to highlight that these OTC diuretics are not the same as those prescribed by doctors. OTC water pills are not regulated by the FDA and may not contain the ingredients they claim to contain.

For this reason, many doctors actively discourage patients from taking OTC diuretics as they could easily be misused and cause dangerous side effects.

And aside from the potentially dangerous side effects of taking water pills, long-term usage can actually cause weight gain. Yes, that’s right – weight gain!

If you take diuretics over a long period of time (this length of time can vary from person to person), your kidneys eventually start to compensate for their use.

Your body retains more water and sodium in the kidneys than it needs. This then causes the body to swell. As a result, a condition known as diuretic-induced edema is very difficult to treat.

Taking Water Pills On Phentermine

Based on the comments in our support group on Facebook and blogs, more and more people are taking water pills alongside phentermine.

If these are prescription diuretics, then this would indicate that the patient has problems regulating fluid intake and may have a heart condition.

In that case, since phentermine can have negative effects on the heart, it is essential that all doctors treating the patient in question are fully informed that the patient is taking water pills and phentermine, and possibly other medications too.

Certain heart problems, such as hypertension, would usually exclude a patient from being prescribed phentermine.

Despite this, in cases where the heart condition is under control, doctors will sometimes choose to prescribe phentermine as a means to help the patient lose weight to help his or her overall health.

However, several phentermine users have been in touch with us to report that doctors, especially those at weight loss clinics, are prescribing water pills alongside phentermine to boost weight loss results and not because of any medical need for diuretics.

If you have been prescribed water pills without being fully informed of what they were for, we urge you to get in touch with your family doctor to seek further advice.

More worrying is the possibility that phentermine users are taking OTC water pills, thinking that it will help them drop weight faster.

Taking water pills unnecessarily can lead to dehydration and a loss of electrolytes, which can then cause scary symptoms such as heart palpitations, muscle weakness, dizziness, and confusion.

And, since OTC diuretics aren’t regulated in any way, it’s hard to say if the recommended dosage on the pack is safe even before you start mixing them with phentermine and the additional side effects it can cause.

Phentermine is also a dehydrating drug, as shown by how it causes dry mouth in most people taking it.

Combining phentermine and water pills without a doctor’s supervision could be a dangerous mix as you may become severely dehydrated, running the risk of dizziness, fainting, and even seizures.

If you’re looking to boost your weight loss results with phentermine, then water pills are clearly not the answer.

Not only do they not help you to lose fat, but they can also even cause the kidneys to overcompensate for their use and lead to water retention and swelling.

The only way to truly lose weight is by eating more nutritious food to fuel your body well and by adding more activity to your day to help build muscle and burn fat.

Phentermine helps you to do these things by suppressing your appetite and boosting your energy levels.

However, if you feel that phentermine isn’t helping you as much as you had hoped, then adding PhenQ to your phentermine prescription is a great way of getting your energy levels up and your hunger down, leading to real long-term weight loss.

Are you taking water pills with phentermine? Have you taken water pills in the past? Please let us know by commenting below.

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  1. I started taking phentermine on july 1st, and by the 5th my feet and ankles were swollen. Am I just not drinking enough water? Water consumption has always been difficult for me.

    1. Hi Lauren,

      You could be retaining water but you could also be experiencing an adverse reaction to the medication. Please speak to your doctor about this.

      Call 911 (emergency medical services) or go to a hospital right away if you notice any of these symptoms while taking phentermine:

      – Chest pain
      – Pounding or irregular heartbeat, or fluttering in your chest
      – Lightheadedness or faintness
      – Shortness of breath, even with only mild exertion
      – Slurred speech or weakness on one side of your body
      – Unusual thoughts or behavior, such as confusion, irritability, phen rage or hallucinations
      – Extreme happiness or sadness (euphoria or phentermine depression)

      Hope that helps!


  2. I take phentermine for weight loss and hydrochlorothiazide for blood pressure. Now my urine is very dark, mild itching, dry eyes in the morning, and tension headaches. Can those symptoms be from dehydration??
    I’ve lost 16 lbs in 1 mo.

    1. Hi Jennifer! We’d suggest that you contact your prescribing physician about these symptoms. A medical professional would be best able to assess whether these signs indicate simple dehydration, or something more serious that needs to be addressed.

  3. I am currently taking phentermine, hydrochlorothiazide & potassium chloride. Since I started this combination of pills in August 2017, I have lost 36 lbs. Right now I feel like my weight loss is at a pause. It is still the same since December. During this period of taking these pills, yes, I am very happy with the weight loss, but I recently went through an episode of severe abdominal pain. I felt like my insides had ruptured. I was having cold sweats and blurry vision. I could barely breathe because the pain was so intense. This happened twice on separate occasions, and both lasted about 15 mins. I have been getting really tired and lazy lately, even while on my pills. I just feel like its use has come to a halt but I’m scared to have a relapse in weight gain so I’m a bit hesitant to stop. Right now my lips have been going through a dry phase. Anyone experience any of this? I do want to take a break for a little while but what a break exactly to stop taking the pills?

    1. Dear Corinne,

      We strongly suggest you consult with your prescribing doctor or your primary care physician. Phentermine was not designed for long term use. The human body creates a tolerance for it. It is also a potent medication, with long-lasting side effects.



  4. I’ve taken phentermine before and lost a little over 50 pounds in 5 months. Now, a year later, I’m taking them again and the first month I did not lose any weight. When I went back the second month, the nurse said she was going to call me in water pills but not to tell the doctor when I talked to her (I know that’s wrong and she was hiding it) but I wondered why.. She told me to take them every other day and I take phentermine every day. It’s been a week and I’ve noticed the water pills have helped regulate my urine as I’ve had problems with that especially during the night I would have to pee a lot. But I’ve been feeling weird and it’s been like this for awhile now. My brain seems to always be mixed up, I have trouble concentrating on one thing and my speech gets messed up while I’m talking. I don’t remember feeling this way the first time I took phentermine a year ago. What could be different? I really need to lose weight but if i agent lost any after this second month I’m just going to stop taking them because I hate the way I feel. I’m to the point I dread taking the medicat8in the morning because I know it’s gonna make my brain all scrambled…

    1. Dear Samantha,

      We definitely recommend you talk about this with your prescribing doctor. We know weight loss is a hard, long journey, but in the end it’s about your overall health, and you can’t sacrifice other aspects of your health over others, especially if the symptoms are as severe or uncomfortable as you describe them. Maybe the solution lies in a change in dose, or maybe another medicine altogether: only your prescribing doctor will be able to give you that answer.

      Best regards,


  5. I am prescribed water pills because I swell in my feet which started when i was 35 due to excessive weight gain. Doctor said my swelling will stop once I lose weight. Had ekg done my heart and health is fine. I just always took water pills for swelling. I was just prescribed phetermine and it seem like with the water pills it is causing my feet to swell more. Do you suggest taking phetermine by itself then resume my water pills after 3 months when i get off phetermine

  6. I am in need of some advice and help. I am going to go see a psychiatrist and get on something that can help with my major depression and bipolar disorder but I need help what to be told what to take and what not to take because this doctor is just giving me whatever to make money. I’m on Xanax 2mg green bars. 4 a day (I don’t feel them anymore) except to not have seizures, which then I weaned myself off Gabapentin which is for nerves so I get what he’s doing… trying to balance me out. I also we need to myself off of Tramadol which I take once in a while because of my back and pain everywhere I’m an esthetician so I’m bending over and waxing the lot not good posture. I am also prescribed Adipex he wants me to take it to lose weight for my back pain. Then I went a couple days ago and some water pills was I just stop taking me cuz I have been researching tonight I am scared of what’s going to happen I’m going to be one of those people who doesn’t understand or know or feel what’s going on inside my body and then die in my sleep, period. I have very abnormal heartbeat and with these downers and uppers he’s giving me and then the vitamins I’m worried. Like I said I am highly depressed and also bipolar so I started taking my prescription from 2014 tonight to see if it works it’s an antidepressant venlafaxine XR 37.5 milligram usually I’m asleep by now but I’m wide awake. I am going to go see a psychiatrist whenever I have time because I want to know what normal is. Normal to me is on all these medications, I do not remember what normal is and when I’m off of them I am a crazy B*T (-)H. Please can someone not judge and give advice. I don’t want to go talk to a psychiatrist says I do not know if they will give me my Xanax, that’s the one thing I am scared of coming off of because I can literally feel myself shaking. Once I open my eyes I have to take my medications or I will be in a horrible mood shaking and tensing up like I’m going to have a seizure. But I just wean myself off of the gabapitin and Tramadol and boy was that a crazy few weeks…

    1. Hi Carissa,
      While we can help answer questions about phentermine, we’re not medically trained in any way so we’re not able to offer advice about medications like anti-depressants. Also, every case is different so it would be hard even for another reader with similar experiences to give you advice. However, from what you say about your doctor and how you feel like you are left in the dark and aren’t sure what is happening with your own body, we would advise you to seek out a second opinion from another doctor, either a psychiatrist as you say or a family doctor who can make referrals to other specialists as and when you need it. We wish you all the best.

  7. I have too been prescribed water pills along with potassium. One pill each every four days. I have taken phentermine 3 times with the same dosing. I also have learned drinking coconut water or equivalent while taking has helped me. I travel a lot and retain tons of water so I feel that it helps me. I do skip a dose of I’m feeling dehydrated.

  8. This worries me. The backstory: I had been having difficulty getting my bp under control for about a year, trying different meds until finally finding one that worked pretty well. But then last October (before phen), partly because I went hyperthyroid on my thyroid dosage, I swelled up to 280 lbs overnight with severe edema. My endo changed my thyroid dosage, and my gp changed my bp meds to include a water pill, basically just splitting it out of the bp med I was already taking into a separate pill so he’d have more control. I quickly recovered, lost 15 lbs by the next day, and with this new medication regimen my bp came well under control to the point where he declared me “fixed” (after regular checks) by February. Then in July, my endo urged me to lose weight and gave me phen.

    I’ve been doing well, have lost 20 lbs and my bp is completely fine (I check it regularly on my own). Even kind of on the low side of normal sometimes, but usually right where it’s supposed to be. But I do get kind of dizzy, or “woozy” I call it, often after exercise. I have checked my bp during these episodes of wooziness and it’s usually quite normal, averaging 100/75.

    So I haven’t known whether to talk to my gp about my bp meds or not. I thought my question was going to be, do I need to go off them, but maybe the right question is, should I stop the losartan/chlorthalidone combo? Or might I be just fine with everything?

    I do tend to have a hard time drinking all 8 glasses of water per day. I average about 5.

    1. Hi Kelly,
      If your BP is good, you’re losing weight, and apart from some dizzy spells after exercise (which many people get with or without phentermine) then I’d say that your medications are currently working well for you. Of course there’s no harm in checking with your doctor to see if you could do just as well if you stopped, so by all means ask, but it could be that you’re doing so well right now thanks to the meds and coming off them might set you back. This article explaining the danger of taking water pills with phentermine was mainly directed at people who self-medicate, thinking that they will lose extra weight that way, but prescribed water pills obviously do a lot of good for those who are meant to be taking them. As for the not being able to drink 8 glasses of water a day, it’s not a big concern if you are getting other fluids through drinks like tea and foods like melon, watermelon and cucumber. However, if your pee is often dark then this could be a sign of dehydration so you should probably think about increasing your liquid intake in some way.

      Hope that helps!

  9. I am currently on phentermine and I have lost 21 pounds in two months and about 45 inches. I was prescribed water pills with my prescription also.

    1. Hi Shawnessi,
      We’re not saying that taking water pills with phentermine is necessarily dangerous, but that they should be prescribed for a medical reason, not for weight loss. The real danger is people taking OTC water pills as these are not controlled and could cause serious side effects alongside phentermine.

      1. The weight loss from a medical doctor is a medical reason the doctors will not give this drug out with out a medical reason obesity would be the reason with Highbloodpressurer and other but ur weight along will do it and the water pills is not dangerous ..My doctor never gave me any to take on phetermines but everybody health is different my doctor got me on a 7 day vitamins u take 7 pills a day for 30days with ur phetermine pill. I stay so full have all my vitamins in my body and I jog I lost 50 pounds on phetermines…..after that my doctor got my insurence to pay for my boobs to get a lift and a tummy tuck for all the extra sag skin .the best doctor I ever had in my life my body and life changed … doctor is my primary and weight loss every body health is different

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