Report on Bontril Side Effects and Usage by AskDocWeb

About Bontril

Picture of Bontril

What is Bontril?

Bontril is the brand name of Phendimetrazine (fen-dye-MET-ra-zeen). It’s used as an appetite suppressant along with diet, exercise, and behavior therapy for the short-term management of exogenous obesity. In this context, short-term means that it is only effective for a few weeks or a few months at most.

How does Bontril work?

Bontril increases your metabolism and reduces your appetite.

What side effects do users of Bontril report?

Side effects that may go away during treatment include headaches, restlessness, overstimulation, nausea, dizzines, diarrhea, constipation, nervousness, difficulty sleeping, or dry mouth. If they continue or are bothersome, check with your doctor. If you notice other effects not listed above, contact your doctor, nurse, or pharmacist.

What are the symptoms of overdose?

If overdose is suspected, call 911 or contact your local poison control center or emergency room immediately. Symptoms of overdose may include restlessness, tremor, rapid breathing, confusion, nausea, vomiting, diarrhea, and stomach cramps.

Some side effects are warning signs that may require medical attention right away. These include:

  • changes in sex drive
  • dizziness
  • fast or irregular heartbeat
  • frequent urination or trouble urinating
  • hallucinations
  • seizures
  • severe headache
  • stomach pain
  • sweating
  • tremor
  • unusual behavior or personality changes

Note: A severe allergic reaction may result from using any medication. If you experience rash, hives, itching, difficulty breathing, tightness in the chest, swelling of the mouth, face, lips, or tongue, seek immediate medical attention.

If you miss a dose of Bontril

If you miss a dose of this medicine, take it as soon as possible. If it is after 4 PM, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Conditions you should tell your Doctor about before taking Bontril:

A history of drug or alcohol abuse
High blood pressure

Use of this medicine is not recommended if you have a history of heart conditions, high blood pressure, or heart disease.

For women: Do not use if pregnant or plan to becoming pregnant. It is unknown if this medicine is excreted in breast milk.

Once you start taking bontril, tell your doctor if you experience chest pain, pounding heart, nervousness, difficulty urinating, mood changes, difficulty breathing or swelling while taking this medication.

Tell Your Doctor if you’re taking any of the following medicines:

Inform your doctor or pharmacist of all prescription and over-the-counter medicine that you are taking. Do not use this medicine if you are also taking guanadrel, guanethidine, furazolidone, or monoamine oxidase inhibitors (MAOIs).

Before you have any medical or dental treatments, emergency care, or surgery, tell the doctor or dentist that you are using this medicine.

Storing Bontril

Store this medicine at room temperature in a tightly closed container, away from heat, light and children.

General Notes

Bontril is on the 2009 WADA list of drugs that are banned for use by athletes and elite sports people. It is considered a performance-enhancing substance.

Take this medicine about 30 minutes to 1 hour before meals. Take your last dose of the day at least 4 to 6 hours before bedtime.

Exceeding the recommended dose or taking this medicine for longer than prescribed may cause serious side effects.

Do not crush or chew this medicine. That may cause increased side effects.

Do not drive, operate machinery, or do anything else that could be dangerous until you know how you react to this medicine.

Avoid taking stimulants like decongestants (found in many over-the-counter cough and cold medicines) or caffeine that may increase your heart rate.

Do not share this medicine with others for whom it was not prescribed. Do not use this medicine for other health conditions. Keep this medicine out of the reach of children.

Common Misspellings for Bontril

Bontril is often misspelled, as many people hear the word verbally, write it down and spell it incorrectly. Here are a few of the most common misspellings for Bontril: Bontrol, Bintrol, Bantrol, Bontrils, Bomtril, and Bentrol.

Bontril Feedback

If you’ve used Bontril, please help others by sharing your experience with side effects. What would you tell your best friend about this product? Please remember that we do not give medical advice. That is for your local health care provider, who is familiar with your medical history. You can use the form below to add your comments, feedback or Bontril review.

Subj: Bontril side effect
Date: 2/4/2003
I have been taking Bontril for around 4 weeks. In the last 5 days I have developed a nervous tic, where I clench my eyes frequently and blink uncontrollably. Also, my eyes feel dry and irritated almost all the time. It has become so annoying that I stopped taking Bontril, even though it was quite effective for me.


Subj: bontril side effects
im a 27 year old female who took bontril fo 6 weeks i lost a total of 30 pounds. i have expirienced tingiling in my left arm it comes and goes what could it be. i stpped taking the medication about 5 weks and i still have the same sensation.


AskDocWeb: Strongly suggest you check with your doctor about that tingling in your left arm. That is one of the symptoms of a heart problem.

Subj: bontril success stories
Date: 11/24/2003
I have been on it for 2 days, bontril pdm. Can you email me back and give me some stories on how people are doing bad or good.


AskDocWeb: We don’t have time to email everyone that sends feedback but if you let us know how it works for you, we will post it here.

Subj: Using Bontril while pregnant?
Date: 11/20/2003
I have been taking bontril for 7 weeks now. I just found out today that I am pregnant. Are there any side effects to taking this while pregnant. Can I continue to take it during my pregnancy?


AskDocWeb: Sorry, the instructions say it is not to be used if you are pregnant. Ask your doctor to recommend an alternative.

Subj: I love it!
Date: 4/28/2004
I love it! I have lost around 10 lbs and am in my 5 th week. I have not experienced many side effects. except for the 1st weeek, it took me longer to fall asleep at night. My mouth tends to be dry, which is good, b/c I drink more water! I am one of those that can not take over the counter diet pills b/c I feel like my mind is going 90 miles and hour but my body feels…blah. They make me feel spacey and Bontril does not, it is very mild, but you have to eat with it, if you don’t you will feel the side effects more.


Subj: Addicted to Bontril
Date: 5/11/2004
I have been taken Bontril for about 5 weeks now but have taken it thoughout the year I think I have become addicted to these pills if I don’t take them I feel down and have no enery. I pop up to 7 a day now.


Subj: Working great
Date: 6/2/2004
I have been taking bontril for 2 weeks now. It is working great. I have already lost 14lbs. Only bad side effect for me is feelings of nausea. Every night. Has anyone else had this problem? Will it go away? Any tips?


Subj: I love it!
Date: 6/19/2004
I have been taking Bontril for about 8 weeks now. I love it! I have, however, noticed some stomach cramping, but I’m not sure if that is due to the med or stress in other areas in my life. Otherwise, I would say that I’m satisfied. I’ve lost 20lbs, but I didn’t start really dropping weight until the last 2 weeks. I’m not sure why, because I haven’t been doing anything differently. Unless it just took time to fully get into my system. I have recommended this medication to friends and family. I’m really grateful this drug was developed. I was never able to take OTC weight loss meds either and feel normal anyways, but this stuff is great!! Thank you to the inventors of Bontril!!


Subj: Migraines
Date: 6/28/2004
I’ve been using bontril for about 10 days and it really have reduced my appetite in a big way. I ?would like to know if I would have some kind of problem with migraines. I don’t get them very often, but today I did and didn’t want to take any medicine, for fear that it would interact with bontril.


AskDocWeb: We saw no mentioned of migraines in the clinical trials for this product. Ask your doctor to recommend something safe for you to take for your migraines.

Subj: Headaches
Date: 8/19/2004
I have just started taking Bontril, I am experiencing headaches. Is this related to the medicine?


AskDocWeb: Headaches are listed as one of the possible side effects of Bontril that may go away with continued use. If it persists or becomes bothersome then check with your doctor.

Subj: Bontril Weight Loss Pills: Side Effects
Date: 8/25/2004
These may include: dry mouth, sleeplessness, irritability, stomach upset or constipation. Other adverse side effects may include chest pain, pounding heart, gastrointestinal disturbances, breathing difficulties and changes in libido. what kind of changes to your libido? So far it’s working pretty good. But what kinds of side effects to the libido?


AskDocWeb: Sometimes, for some people, it increases libido, but typically it means a reduction in your sex drive.

Subj: Bad case of acne
Date: 10/21/2004
I had been taking Bontril for about 5 weeks. I experienced the dry mouth and increase in energy which subsided within the first week or two. So far I have lost 7 pounds total. I stopped taking it about a week ago because I was breaking out all over my face, like a bad case of acne. I tried everything to clear up my complextion while I was on Bontril but the acne persisted. Since I stopped using Bontril my face has begun to clear up and there are no new outbreaks.


Subj: Should I worry?
Date: 12/17/2004
I took Bontril since months ago with no side effects… This time I’m experiencing trouble in breathing ,chest pain, tooth pain, tense jaw, cold extremities and severe headache….a touch of dizziness and insomnia….How much should I worry?


AskDocWeb: Enough to discontinue use of any diet pills. Any diet pill may cause severe symptoms as you have described. If after discontinuing the diet pill and symptoms continue see your doctor and have an EKG done to check your heart rhythm. You will find you will feel so much better, just by changing your eating habits. Make sure your diet includes chicken, fish and vegetables. And exercise, even if it’s just walking three times a week. Good luck.

Subj: Worried
Date: 12/21/2004
Hello Everyone, I have been taking Bontril for about 2 weeks now and I have not been hungry at all. I have not lost any pounds but my clothes are starting to fit better. Is there a reason that the scale is not showing it? I am starting to get worried that this is not working for me, but I know my hunger is slim to none now, can anyone help?


AskDocWeb: Just the fact that your clothes are fitting better tells you something is happening. It may be that the fat is being replaced with muscle. That would account for the scale not showing a change. Keep at it awhile longer you should see results on the scale too.

Subj: Follinex
Date: 1/1/2005
What do you think of follinex for a woman with hair that is becoming thinner and thinner–so fine that it will soon be invisible? Is scalp stimulation helpful? Is DHT the chief culprit in hair loss? PLEASE DO NOT USE MY NAME. Thank you. Gratefully,


AskDocWeb: DHT is the chief cause of hair loss in men but most women lose hair for different reasons. Hair loss in women is not well understood by medical science. Scalp stimulation should slow your hair loss to some degree but it is not going to stop it. At present, there is no product we would recommend for women with hair loss. That said, we invite you to share your experience with any hair loss products you try. That would be helpful for other women with this problem. Read more feedback about Bontril

Most recent post: June 29, 2017

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