Generic Name: phendimetrazine
Brand Name(s): Adipost, Bontril, Melfiat
Medically reviewed by Ahmed Zayed, MD on June 19, 2018

With the prevalence of obesity increasing at an alarming rate1, many patients and physicians are now turning to prescription weight loss and anti-obesity drugs to help reduce the impact that excess weight has on a patient’s general wellbeing. Obesity has been linked to many adverse health effects. Excessive weight gain is known to contribute to the development of metabolic disorders, as well as serious medical conditions that may shorten a patient’s lifespan2.

Bontril has been proven an effective approach to the management of patients with a BMI that is 30 or higher, classifying them as obese. This drug is used in combination with a diet and exercise plan and is advised for patients who are unable to achieve effective results with diet modifications and physical exercise alone. Due to a number of side-effects associated with the drug, some patients may not be appropriate for this drug. Understanding the working action, side-effects and indications of Bontril will help patients better understand if this is a good option for them.

How Bontril Works

Understanding how any type of medication or supplement works should be necessary for a patient before they start taking the pills. Bontril contains an active ingredient known as phendimetrazine tartrate. Phendimetrazine tartrate is classified as a phenylalkylamine sympathomimetic agent1. This is a chemical that works similarly as amphetamine in the human body, leading to appetite suppression that helps to reduce the daily caloric intake of the patient, while also enabling them to eliminate cravings and binge eating at the same time.

How Bontril Is Used For Weight Loss

One of the significant factors leading to weight gain and obesity is overeating. The majority of obese people tend to consume more calories than they burn off in a single day. When all calories consumed are not burnt off, the excess calories are stored as fat – this is essentially what leads to weight gain in the general population. This is why Bontril is such a useful option when it comes to losing weight, especially among people who tend to find it difficult to lose weight with their current weight loss efforts.

Bontril helps to suppress appetite. When the patient experiences a reduction in their appetite, they start to eat smaller meals. The patient also feels less hungry between meals, making them less likely to reach for unhealthy foods during the day, such as potato chips, chocolates, doughnuts, and other high-carb foods. Patients may also find it easier to become in control of binge eating, which is often caused by high-stress levels and tiredness.

Dosage Information For Bontril

It is very important for patients to take note of the dosage instructions they are provided by the prescribing doctor. Adherence to this dosage is vital as a doctor will prescribe the most appropriate dosage for the patient based on their current weight, existing health conditions, and medications they are currently taking. Patients are advised not to take more than what the prescribing doctor has advised.

In most cases, a patient will be prescribed a 35mg tablet of Bontril, which may be taken either two or three times each day. Dosage timing is important as taking this drug too late in the day can cause the patient to feel energized at night and make it difficult for them to fall asleep.

Side-Effects Of Bontril

A large number of potential side-effects may occur when a patient starts to take Bontril. The most concerning side-effect is an addiction since this is a controlled substance that is closely related to amphetamines. This is another reason why patients are advised to follow the dosage instructions provided to them, not to take more of the drug than advised, and to follow the instructions of their doctor when they are advised to go off the drug. Patients with a past of substance addiction and abuse should also ensure the prescribing doctor knows about this before they use this drug.

Patients may experience the following side-effects4 when they take Bontril:

  • Dizziness
  • Blurred vision
  • Restlessness
  • Hyperactivity
  • Insomnia
  • Tremors
  • Headache
  • Flushing
  • Diarrhea
  • Constipation
  • Upset stomach
  • Impotence (erectile dysfunction)
  • A low or increased libido

Patients also need to be wary of the fact that the drug may cause more serious side-effects in certain cases. Should the side-effects experienced while using the drug feel severe or affect the patient’s day-to-day functionality, they are advised to get in touch with their doctor and to discuss these side-effects with them.

Signs Of An Allergic Reaction

Patients need to avoid using this drug if they are allergic to the active ingredient, phendimetrazine, or have previously experienced allergic reactions to other pharmaceutical stimulants. Signs that the patient may be experiencing an allergic reaction to Bontril may include itching, a rash, trouble breathing, more severe dizziness, as well as swelling of the throat, tongue, and face. Urgent medical attention may be needed in case of an allergic reaction.

Signs Of An Overdose

Overdosing on this drug can be hazardous to the patient. The patient needs to ensure they adhere to the dosage instructions that the doctor has provided. Should symptoms associated with an overdose of Bontril be experienced, the patient should call 911 or be taken to an Emergency room urgently. Signs that a patient may have overdosed on this drug may include an irregular heartbeat, unusual restlessness, rapid breathing, chest pain, and hallucinations. Some patients may also experience a loss of their consciousness or seizures when they take a dosage of this drug that is too potent for them.


Bontril has been developed to offer obese patients a pharmaceutical option for the treatment of the excessive weight they have gained, as well as the possible complications that they might have experienced because of obesity. The drug is considered relatively safe for short-term weight loss but may cause certain side-effects to develop. Additionally, some patients may not be appropriate candidates for this drug.

Patients who do not qualify for the use of Bontril or similar prescription drugs can opt for an alternative like PhenterPro. This alternative option also contains a formula that offers an effective way to suppress the patient’s appetite, without causing significant interactions with other drugs or existing health conditions.


1 M. Agha and R. Agha. The rising prevalence of obesity: part A: impact on public health. International Journal of Surgery. Oncology. 22 June 2017.

2 Multiple Authors. Health impacts of Obesity. Pakistan Journal of Medical Sciences. 2015.

3 Phendimetrazine Tartrate. PubChem Open Chemistry Database.

4 Bontril. RxList.


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