hair loss on phentermine

Although hair loss isn’t listed as one of the phentermine side effects, it is something that is reported by many phentermine users, both on the phentermine forum and on discussions on social networks like Facebook. However, while it may not be as a direct result of phentermine, hair loss is linked to vitamin deficiencies, weight loss and underlying medical issues, all of which can affect those taking phentermine. So, here we explain why you might experience hair loss on phentermine and what steps to take to minimize hair loss while losing weight.

Hair Loss On Phentermine

As hair loss isn’t known to be a side effect of taking phentermine, it’s not listed among the many other common and uncommon side effects here. But with many women making the link between taking phentermine and noticing that their hair is falling out in clumps or getting thinner, such as in this forum post, there is evidence that would suggest that the way in which phentermine can lead to hormonal changes and rapid weight loss could be to blame.

The type of hair loss, or alopecia, reported on phentermine typically starts to occur around three months into the treatment and can continue for as long as you are losing weight. The hair loss experienced by many phentermine users is most often caused by changes in diet, such as restricting calories or eliminating foods, and the hormonal changes which can occur when losing weight with phentermine. This hair loss does not tend to be noticeable straight away because the hair follicles lie dormant on your head for several months after the initial damage is done. By the time that you start to notice the hair loss, your body is already starting to correct the problem; within weeks of noticing this initial hair loss, you should then start to feel little hairs coming out of your scalp, indicating hair regrowth.

The type of hair loss you may experience on phentermine should be with the hair coming out at the root, which is normal hair loss that you would experience when washing or brushing your hair, albeit at a faster rate. However, if your hair is becoming dry and brittle and breaking off away from the root then this could be a sign of an underlying medical condition, such as hypothyroidism. But, whether you believe your hair loss to be phentermine-related or the sign of an undiagnosed issue, it is advisable to report it to your phentermine doctor for help and advice.

How To Minimize The Causes Of Hair Loss On Phentermine

There are many causes of hair loss, most of which can be treated by ensuring that you eat a balanced diet supplemented with a good multivitamin to add the nutrients you might be missing out on. Here we run through some of the reasons you might be experiencing hair loss on phentermine and how to help minimize the problem.

Lack Of Protein

Hair is mainly made from protein so if you’re not getting enough protein in your diet then your body may react by slowing down hair growth. A lack of protein plus the added hormonal changes and dramatic weight loss could all result in hair loss on phentermine. To minimize this effect, be sure to eat your recommended daily intake of protein – 46 grams of protein per day for women and 56 grams of protein for men. Click here for the top ten sources of protein with the fewest calories, and check out this list of protein-packed snacks to find out how to boost your protein intake between meals.


Close to 10% of women aged between 20 and 49 suffer from anemia due to an iron deficiency (the most common type of anemia), which can result in hair loss among other symptoms, such as fatigue, dizziness, and an ashen complexion. If you think you may have an iron deficiency then a blood test by your doctor will confirm this, and then the problem is easily fixed with a simple iron supplement.  A diet low in iron can also restrict your ability to lose weight so even if you’re not anemic, eating healthy foods rich in iron such as leafy greens, lean red meat and pumpkin seeds can help to boost fat burn and weight loss with phentermine.

hair loss on phentermine

Vitamin B Deficiency

Low levels of vitamin B are an easily correctable cause of hair loss. Many people taking phentermine are advised to get vitamin B12 injections to boost energy, but it would be more beneficial to take a multivitamin such as Phen Vites which includes all of the vitamin B complex. This is because other B vitamins, such as folate, are also lacking in the modern American diet, as reported in a recent analysis of the 2001-2008 National Health and Nutrition Examination Survey (NHANES). Additionally, B vitamins help to minimize phentermine side effects such as dry mouth, depression, and anxiety, and all B vitamins play a part in the way in which the body converts food into energy. And, in the case of hair loss, the B vitamin Biotin (B7) has been directly related to the prevention of thinning hair, so this is a vitamin that you shouldn’t be missing out on if you’re worried about potential hair loss on phentermine.


It’s advisable for anyone with weight problems to get their thyroid checked as it’s an increasingly common for women to be diagnosed with hypothyroidism, the term for an under-active thyroid. As well as weight issues, hypothyroidism can cause hair loss, but this problem can be rectified with the help of synthetic thyroid medication which will restore the normal functioning of your thyroid, helping to resolve thyroid-related problems, such as weight gain and hair loss.


Like hypothyroidism, Polycystic Ovary Syndrome (PCOS) can be an underlying cause of weight gain, and is also linked to hair loss due to hormonal imbalances in the body. Many women with PCOS find phentermine to be a great way to help them to establish a healthy lifestyle of diet and exercise, making weight loss easier which in turn helps to ease the symptoms of PCOS and restore their hormonal balance to minimize symptoms such as infertility and hair loss.

Dramatic Weight Loss

The crucial but indirect link between phentermine and hair loss is dramatic weight loss; phentermine can lead to dramatic weight loss and this in turn can cause hair loss. Sudden weight loss is a type of physical trauma which can result in hair loss, even if the weight loss is ultimately good for you, as is usually the case when a patient is prescribed phentermine due to obesity. The best way to avoid hair loss as a result of dramatic weight loss is to ensure that you’re eating a healthy and balanced diet containing enough calories to sustain your activity levels and keep your metabolism functioning properly. This will ensure that you lose weight at a healthy rate of around 2lbs per week and not losing precious muscle due to extreme dieting or excluding essential food groups.

The Nutrients You Need To Minimize Hair Loss

To improve the health of your hair while losing weight, be sure to eat a diet including these nutrients:

Omega 3 Fatty Acids

Eat sources of omega 3 such as oily fish, avocado and olive oil throughout the week to keep your hair healthy while also helping to burn fat and boost your metabolism.

Iron & Zinc

Iron and zinc work together to improve the health of your hair, and are both essential for a healthy body too, meaning more weight loss. Experts recommend eating lean red meat twice per week as it is rich in both nutrients. Non-meat sources of both zinc and iron include pumpkin seeds, sesame seeds, lentils, cashews and quinoa.

Vitamin C

Vitamin C helps the absorption of iron, so you should be sure to eat plenty of foods rich in vitamin C too. More than half of adults were found to lack this essential vitamin in a recent study of the modern American diet, despite it being found in abundance in a variety of fruits and vegetables, including kiwis, red peppers, citrus fruits, broccoli, Brussels sprouts and cantaloupe. But, if you’re not always able to get a range of fruit and veg, the weight loss multivitamins Phen Vites provide your recommended daily dosage of vitamin C.


Eat plenty of protein to minimize the possibility of hair loss on phentermine; these top ten sources of protein are a great place to start, and if you’re a vegetarian or vegan then check out these veggies with the most protein.


Eggs are a great source of biotin, and they also contain vitamin D – another important nutrient for healthy hair. If you’re not a fan of eggs then vitamin D can also be absorbed by spending around ten minutes per day in the sun and your daily recommended amount of biotin can be found in Phen Vites, the only multivitamin specifically designed to help those losing weight with phentermine to get all the nutrients they need for good health and weight loss.

Vitamin E

Vitamin E contributes to healthy skin, hair and nails, so it’s important to meet your daily requirements if you’re worried about hair loss on phentermine. However, up to 98% of Americans don’t get enough of this crucial vitamin, often because it’s found in ‘fatty’ foods such as nuts, seeds and oils, even though these fats are the good fats which you should be eating to help boost metabolism and boost weight loss. If you think you might be lacking in vitamin E, then taking Phen Vites each day will give you your recommended daily limit to help improve the health of your hair.


Have you experienced hair loss on phentermine? Let us know by commenting below.


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25 Responses

  1. This is the third time in my life that I have used phentermine and I have lost hair every time I have used it. I am 56. I am getting so thin on the front of my head that I am afraid to use it anymore. Also I have craved food like crazy since I quit taking them. I have already gained back 5 lbs in a month. I am so upset and really am trying hard.

  2. I have noticed my hair is slightly finer than normal and that when I stop taking Phen my hair suddenly becomes overly greasy (is this also a side effect)… I am using Biotin to help this, also it seems to make me more argumentative and impatient. With my loved ones!!

    • Hi Jennifer,
      Phentermine is dehydrating so maybe you hair follicles compensate for this by producing more oils which then leads to greasiness once you stop taking the phentermine. Phentermine does also cause psychological effects and has been said to ‘amplify’ emotions and reactions, so whereas before you might have been a little irritated, on phentermine you can become very angry and agitated more easily. It’s important to make your family aware that the medication is affecting you like this, and to explain in moments of calm that it’s not who you really are or how you really feel and that with their love and support you can succeed at losing weight and get back to your old self again. Good luck!!

  3. I have also experience hair loss w/phentermine. I have twice used if for weight loss & both times had a great amount of hair loss. Most recently 1 year ago and I am still losing hair. I can’t understand why I’m still losing hair a year later. I do have shorter hair coming in the re-growth of the hair already lost. Scared it won’t all grow back. I probably will never use phentermine again even though I have had great success with losing weight it is not worth all the hair loss.

  4. I lost so much hair. I’m thinner yeah. Last about 40 lbs but at this cost? If the Dr had warned me, I wouldn’t have done it. I quit the diet a year ago. I’m not seeing much regrowth. Probably going to get extensions just so I don’t feel so self conscious. Be warned.

    • Tiffany your post is like I wrote it myself. Have been looking into extensions.

  5. I have quite a bit of hair loss as well after 6 months & 50lbs. I’m almost at goal & have less than 60 days of prescription left. I’ll start a B supplement & do a final review of my experience with Dr. but likely will be stopping the Rx & hope my hair comes back & weight stays off. Overall happy to be back in single digit clothes & so far no one notices the thinner hair but me.

  6. I am suffering from dandruff and hair loss please tell me about any treatment for hair loss and control dandruff without any effects.

  7. I have been on it for a month and a half. Extreme hair loss. I stopped right away when noticed hair was as thin as it was. 26 pounds down is great, but i want my hair. I will for sure incorporate your great suggestions but i will do it with out the pills. Thank you for this great info.

  8. I have been taking phentermine for a few months and noticing hair loss to the point it gave me a bald spot on the back of hair line on my neck. I stopped because my mom took it and is almost completely bald!! She stopped 8 yrs ago and her hair is still falling out! When I my got script filled at walmart it listed irreversible alopecia. Which means it doesn’t grow back and it keeps falling out!! Of course the warning was on the second page of warnings and at the end. Yes it was nice to see rapid results. But who wants to be bald after you worked so hard to look good!?! My insurance said I had to take it for 6 months before they paid for gastro-bypass surgery.. I wished I hadn’t!

  9. Lost 50 lbs four years ago and my hair has never come back. It’s so thin in front and at the crown that I had to get a human hair wig. I think I’m now going through menopause which isn’t helping. I’m 53. Oh and I gained some of the weight back. Dr refused to let me stay on the medication for very long. So now I take boxing classes. Part of the problem is that I also don’t eat well. I live alone so I don’t cook. I typically eat only one meal a day and have a few drinks at night. Not good.

  10. Yep!… Am so done with this weight loss drug..never knew why my hair was getting dry and breaking off. Every 3 weeks I visit the weight loss clinic, they never mention any thing about hair loss..or maybe I just never said anything..I always complained about dehydration! So along with the Phenterminethey put me on topamax for a more rapid weight lost. And yes! This one also takes out your hair!! …so suffice to of yesterday…I completely stopped all medications…my weight is 158 and am 5’8″. My heaviest weight was always around 192..but never reached 200…because that is when I would go to the dr….am done and completely bald!

  11. I have taken Phentermine off and on for about 8 years. I lost 35 lbs during my first experience using this drug. I didn’t notice hair loss til later. I asked the nutritionist at the weight loss center if it could be from Phentermine. She said yes it could and told me to take Biotin. I also made sure I got the B12 shots weekly. During one of my annual skin checks, the DR said my scalp was abnormal and took a sample. The results indicated alopecia and hypothyroidism. She suggested I stay off phentermine. My hair is still thinner on top.

  12. Add me to the list, I started losing my hair during the third month on Phentermine. I have thinning around my hairline and a bald spot the size of a quarter near the top of my head. I\’ve been getting the B12 shots weekly as well and this still happened. I had no idea this was the cause. I\’m done!

  13. Same here I\’m done. I hope I don\’t end up bald. The hair loss has slowed but not stopped. Wish I had connected the dots sooner. I lost 35lbs and 6 months after I had stopped the Phen my hair started falling out drastically….. it\’s not as bad now but it hasn\’t stopped and it\’s been a year since the first shedding. I\’m 52 and worried about being bald.

  14. Add me to the list also, I wish someone had warned me about this problem.
    I\’ve been on phentermine for 5 months (until today) and my doctor told me I could take it for as long as I wanted to with no problems. I\’ve been losing a lot of hair every day for the last 3 to 4 weeks. I\’ve lost 45 lbs. but at the sacrifice of my (normally very thick) hair. I am terrified by what I\’ve read here about it not stopping and not growing back in. I take a multi vitamin along with extra biotin, vitamin B12, D3, and a probiotic every day. I am 53 and also taking hormones. The only thing I am not taking is extra iron, vitamin C or E as suggested. Guess I\’ll add that too.
    Good luck ladies, spread the word!

  15. I can relate to hair loss with phentermine also. After being on the drug two months, I noticed a significant amount of my hair coming out. Still not knowing it was the phentermine causing it, I continued to use the drug a few more months. My scalp started showing a lot in the crown of my head. I was literally going bald. I\’ve stopped the phentermine now & pray my hair comes back! It is not worth it to me. The manufacturing company needs to list hair loss as a side effect. I did eat a well rounded diet with ample amount of protein while taking the drug. Hair loss was not from a vitamin deficiency.

  16. Me too! I noticed my scalp was very itchy about a month into taking it then started noticing that my, already thin head of hair, was getting thinner…It took me another month to figure out it was the Phentermine…I stopped today and won\’t do that again.
    I\’m hoping my hair does grow again… it\’s scary to read some of the previous post that hair doesn\’t grow back. Perhaps the pharma company should pay for our extensions!

  17. Unfortunately, I too am having significant hair loss. I didn\’t think it was the phen. because it began after six months. I get weekly B12 injections, take B6 and Folic Acid daily. I also take a biotin supplement and a multi purpose vitamin. I\’ve lost 53lbs and am very close to my goal weight. I pray that by stopping the prescription my hair will come back. What good is a rockin body when you\’re bald?

  18. I have been on phentermine for about 6 months and my hair was super thick and long. Now my hair is thinning out and falling out in chunks. I\’m scared to take showers, brush it or even run my fingers through it since it falls off so easily. I have lost almost 40 pounds and my MD says it\’s normal and isn\’t worried but I am since I am beginning to see bald patches in my head. I even had to cut a few inches off so it wouldn\’t fall as bad but it didn\’t help. I want to stop taking them but she want to \”wean\” me off of them since I\’ve been taking them for a few months now. I see no signs of new hair coming ut. I haven\’t had this bad of a reaction before with this pill, I just turned 28

    • This is exactly my situation. I just got these painful blood plasma injections in my scalp to help grow my hair. It was so painful andf I consider myself someone who can take pain. A big needle going back in forth in your temples isn\’t an easy thing to take. On top of all this it caused hemmroids, so there goes my lovelife.

  19. I\’ve been on Phentermine on and off for almost 4 years. I lost 20 lbs the first time I took it. Everyone was amazed how fast I dropped the weight and I still continued to eat the foods that I wanted. Too good to be true until almost 3 years later I began to notice a significant change in my hair. It became noticeably thin and sure enough I started developing bald spots the size of quarters. I didn\’t think it was from the Phentermine. I was thinking it was stress related. I went to my dermatoglist and she gave me steroidal injections into my scalp. It hurt felt uncomfortable. I would get those injections 2-4 weeks apart and I finally noticed hair growth. I had my suspicion that it was because of the drug but I still continued to take it. 6 months later, the same thing happened again. Another bald spot but in a different location. I got my labs checked out to rule out any autoimmune diseases. It was all negative. I concluded it was from Phentermine. Yes, I lost significant amount of weight (to which I gained it all back) but it was not worth becoming bald for.

    • I spent weeks googling his drug neither the physician nor the blogs made me aware of this the witchy dropped off fast. I spent about 3 months on Phen before shedding occurred then came the clumps after the physician suggested I discontinue monitor the hair loss. A year Later I’m so stressed about my hair… I’ve gained back my weight, my hair is finally stabilized but there’s no significant regrowth. I’

  20. I am 35 and have very thin hair THANKS to this stupid medicine… which I will never ever take again. Yes I 55 pounds in 6 months, but honestly I rather be fat with my full set of hair.
    And warning phentermine also gives you a false positive for amphetamines if you ever need a drug test for work.

  21. I wish I knew about the hair loss. I had thin hair on top as it was. Now it\’s more than thin. I actually have bald spots. I\’m stopping this drug now, getting all the vitamins and pray my hair comes back

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