Phentermine Anyone Have Strange Side Effects?

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jen Says:

I just started taking this medicine for weight loss. I am having hot flashes and cold chills, terrible headache and a tingly head. I feel awful. Has anybody taken this and had the same reaction? If so did it pass after a few days? Gotta say this...I am not ever hungry! Like to hear from anyone that has taken this med. Thanks :)

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bre Says:

hi jen! I have also been taking phentermine for about 2 months now, and yes, the medicine can be great, but the side effects aren't always pretty. when i first started taking them, i had a headache, was super thirsty, and felt like i could crawl out of my skin! I now only get an occasional headache and still deal with the insomnia. what dosage are you on? maybe you should start small, say 18 mg and then move on to 30 when that doesn't work anymore, then 30.7 (the highest dosage) I had to jump down to 18 mg when dr started me at 30 because it was too much at first, then when I felt a bit more acclimated, I was bumped up by dr. to the next dosage. Let me know how you're doing!

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jen Says:

Hi Bre! My doc started me on 37.5mg.That is the max dose.She will only let me have them for 2 months.Today I took half in the morning and took half at 2.I think I dont feel as bad as I did yesterday.I was realy hoping for more energy! Bre,how much weight have you lost in the two months you have been on them?Thank you for answering me! :)

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carole Says:

I got the Drug from a Dietician, she had advised me to start taking half and after 3 days increase to an entire tablet. That worked great for me. You will have a dry mouth as a side effect( it reminds you to drnk a lot of water) so thats a good thing. After a while getting used to eat less and smaller portions I had skipped a day or so and that worked great for me a s well. I just hit my 30lb mark and continue to do great on this medication. I started in June so hopefully by the Holidays I I will reach my goal of 50 lb loss all together. Good luck to all

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linda Says:

Hi, I'm Linda and I have been on Phentermine since June. Lost the weight and was doing fine until just recently when all of a sudden I started feeling so draggy and having no color in my face, dark circles under my eyes and I hear ya about the freezing and then the HOT FLASHES. This did not happen to me to start with, but now my body has gone haywire. I am bruising everywhere for no apparent reason and I feel just awful. I had no problems to start with but now I have got things going on that I don't know what in the world has gone wrong. Has my blood count been affected??

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anita Says:

DRINK WATER!! Tons of water and the headaches will dissappear.

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Jen Says:

I stopped taking this medication after 14 days.It turned my life upside down.I had a terrible temper and was very angry.My children and my friends and family did not like me on this! I did lose 11 pounds but it was not worth it.I decided to stop taking it but I still have the meds.My doctor told me nothing about the side effects! Maybe one day I will try again but at a much smaller dosage!

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Stephanie Says:

I know this thread is over a year old, but hope you will get this comment and respond. I am doing the exact same thing as you were. More time on the Phentermine BEFORE anything started going on at all. I am getting Hot Flashes every nite for two weeks now, hair loss, and have lost a couple toe nails as well (eeww, I know). It is working great for the weight loss as well as giving energy to keep the walking up really well. Total loss is up to 38 lbs now and the inches are melting!. I just wondered how your outcome was with all these side effects or if maybe it was more of lacking something in your diet as well as mine right now versus the pills. THANK YOU

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Christine Says:

I just started taking it and I am having really bad hot flashes. Did it go away?

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JoAnna Says:

I am cold all the time while on it! I haven't hit the hot flashes yet, but there's a constant cold sensation and chills especially at bed time. havent had any other ill effects.

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rebecka Says:

I have taken them for a while now under doctors orders ,
but I have learned a few things.After i was 230 pounds now down to 167 just few months I wouldnt go hungry,

well after the pill wore off I would be lightheaded ,so right before I took it I would eat something and drink tons and tons of water
Then after that wait an hour and take the pill .Never take them to late though and when I say early I mean I take one at 6am then the other at 12pm so it gives it time and by night I can sleep.

Also make sure when you take them dont sit around the pill gives you energy so thats when I will clean house walk ect..

Other then that I have been fine I dont drink tea or soda to much sugar that will not help with the extra energy.

Oh and the one Im takeing is Phentermine HCL 30mg twice a day with my doctors orders

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Lesa Says:

Just started taking Phentermine today. And the dosage does go higher than 30. I'm on 37.5.

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Monica Jones Says:

I am taking 37.5 mg of phentermine one a day, I have been having the night sweats and then all the sudden I will be cold, body even gets ice cold. I have been taking for about 6 months now, the main thing I am worried about is the ice cold feeling.......whats wrong with me?

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sherisha Says:


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sheri Says:

I am on this to and i cut the pill in half and that all i take every day and i a m not hungry ,, but having bad night sweating ,, wakesme up

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J Says:

I take Phentermine 37.5 once a day, I've lost 44 pds in approx 4 months.

The only side effect I've experienced (which is not listed as a possible side effect), is semen leakage. I've searched the web, and I've seen reports by other males of experiencing semen leakage after taking Phentermine for an extended period (one of the reports was a male that had been taking Phentermine and lost 40 pds in 5 mos).

In my case, it typically occurs after urination. I will finish urinating, and may feel like I still have to pee. Some slight pressure results in semen excretion, with no related feeling of orgasm. I have to ensure that all is excreted though, otherwise the leakage may continue after I leave the bathroom.

There is no guarantee that this is related to Phentermine, but it *never* occurred until after I started Phentermine, so there is a strong likelihood in my mind that it is related (especially after seeing similar reports online).

According to my searches though, this could be related to various other issues, and I (and anyone else experiencing such effects) should report such issues to a medical professional for diagnosis.

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makalak Says:

I started 15mg Phen for a week, and couldn't handle it. First few days were OK, but after day 5 I felt like I was on speed, my mood was uncontrollable, I was having panic attacks, and terrible insomnia. Not to mention weird sensations like chills, jitters, and really high heart rates when exercising. Do these side effects go away, should I just wait it out?


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J Says:

@makalak, talk to your dr, but it sounds like it's either too high of a dose for your system, or it's not a delayed release pill. make sure you don't drink alcohol with it, do take food with it, and try to reduce caffeine or other energy boosting supplements, as that may be causing the effect you're experiencing.

My wife, for instance, is very sensitive to sugar, caffeine, phentermine, etc, so she always has to reduce her intake to 1/2 or even 1/4 of what I can handle. Sounds like a similar situation with yourself.

Additionally, make sure you're seeing a good physician to oversee your dosage. I recommend an "internist" (also labelled as a "doctor of internal medicine", often called a "doctor's doctor"). Internists are pretty much all-around specialists, and are better qualified for dealing with drugs such as phentermine than most doctors that have a limited specialization.

Good luck!

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makalak Says:

That could be my problem...I was instructed to take it on an empty stomach, and while I do not consume caffeine, I do drink red wine pretty frequently. I will talk to my doctor, thanks for the advice!

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The Olivas Family Says:

Me and my husband.have been on the 37.5 for a little over a and he has lost 15 I have lost 17 we take one a day with food the only side.effect that stayed for me is the severe dry mouth and for my husband is he is always.cold we find it go to sleep at night and the libido has went through the roof with me and him the impotence has half way effected him he is not happy at all he isn't completly but after 1 or 2 times its a rap for the night results are great so far side effects are managable energy levels are wonderful I just hope it lasts hope this helps please if any one has similar issues please resond to let us know we are not alone Thanks

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Stacey Says:

I had a headache the first night I am on 30mg capsules and yes I am never hungry either but make sure u eat something and drink water i have cut out things that I used to eat. I don't go to gym or anything but I am up and active now I am not sleeping half the day . The headache is gone I did have a tingle sensation thru my whole body almost felt like I was drunk the first day. I think after my first 20 lbs are gone I will go to
Lower dose so I don't build a tolerance then loose 10 lbs that way and then get my additional 20
Lbs with the higher dose again . I will continue eatin right and hopefully keep te weight off . I don't have major side effects I took advil for my headache

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