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The difference between phentermine and phendimetrazine


It’s important to do your research when comparing weight loss supplements, and to choose the one that best suits your needs and goals. Taking any diet pill without the consultation of a doctor is never recommended, which is why Phentermine doctor James Kojian provides free consultations before issuing the supplement to clients.

Phentermine is compared to many other weight loss pills, including Phendimetrazine. Let’s review the differences between these two supplements to help you in your fast weight loss efforts:


Phentermine is an obesity drug best known by the brand name Adipex. Phentermine promotes weight loss by stimulating the hypothalamus region of the brain, releasing biochemicals that suppress the appetite, resulting in fewer food cravings and more effective calorie-control, which in turn leads to stomach shrinkage and weight loss.

Phendimetrazine, known by the trade name Bontril, works in a similar way, but with added precautions that means it’s typically not prescribed to people under the age of 17. These drugs are classified as sympathomimetic amines, a name given to medications that mimic the effects of neurotransmitters and hormones, and they belong in the anorectics, or appetite suppressant, class.


Depending on the dose, Adipex can be taken three times per day (for smaller doses) or once a day (for larger doses). In the first instance it should be taken 30 minutes before eating and spaced out over the course of the day; in the second instance it should be consumed within an hour of eating breakfast.

Many Phentermine users prefer taking one tablet a day. It’s safe, convenient, and they don’t have to worry about remembering to take several pills throughout the day.

Bontril comes in two forms; extended release, taken once per day 30 to 60 minutes before breakfast, and immediate-release, taken 2 to 4 times a day an hour before eating.

Your doctor will advise which dosage is best for you and make adjustments as needed. They will also tell you how long you should be taking the medications for, as it’s possible to develop a tolerance to anorectic drugs like Phendimetrazine and Phentermine after a few weeks of regular use.

It’s important not to crush your tablets or to consume them in a way not recommended by your doctor. While there should be no issues with immediate-release tablets, crushing a prolonged-release tablet prior to ingestion will cause more of the medication to be released at once, potentially leading to an overdose and to a number of serious side effects.

If you’re taking Phendimetrazine tablets several times a day and miss a dose, don’t double-up for your next dose and simply continue as normal unless otherwise directed by your prescriber. This could potentially cause an overdose.


Side Effects

The side effects are where Phendimetrazine (Bontril) and Phentermine (Adipex) really differ.

Adipex is more complicated because it is deemed to be more effective in the wider population and produces far fewer sider effects, with the average user experiencing few, if any, adverse reactions. It can be prescribed in patients as young as 16 and it is also thought to have a lower abuse potential than Bontril, with Adipex rated as “some potential for abuse” and Bontril as “moderate potential for abuse”.

Phendimetrazine side effects can range from relatively mild effects such as nausea, dry mouth and headaches, to more serious reactions such as:

  • Heart palpitations
  • High blood pressure
  • Insomnia
  • Restlessness
  • Dizziness
  • Tremors
  • Swelling of the extremities
  • Chest pain
  • Shortness of breath

These side effects can be present in any patient and any dose. If you experience any such issues taking Phendimetrazine then you should stop your treatment and consult with a medical professional immediately.

Neither of these drugs should be consumed if you are pregnant or breastfeeding, as very little is known about the risks associated with Phendimetrazine/Phentermine use during pregnancy and it’s always best to be on the safe side. There is no known issue with regards to fertility though, and these drugs are often prescribed to women who are struggling to get pregnant because they are overweight.

There are a number of contraindications, including a few major and many minor. These drugs should not be taken alongside any recreational drugs (especially amphetamines and other stimulants) or painkillers, and there are also some concerns regarding excessive use of non-steroidal anti-inflammatory drugs during Phendimetrazine/Phentermine consumption.

These contraindications are not of immediate concern and should not be an issue in small to moderate consumption, or in the event of an accidental dose or oversight, but they are thought to increase the risk of adverse reactions and should therefore be avoided where possible. This is one of the areas that you doctor will go over, so make sure you’re upfront with them regarding any medications (prescribed, herbal and recreational) that you are taking or plan to take.

Alcohol consumption is not advised during a course of Phendimetrazine or Phentermine, as this can also increase the risk of certain side effects.


Numerous factors are taken into consideration to determine if an individual is a good fit for Adipex or Bontril treatment. Bontril (Phendimetrazine) is typically not prescribed to anyone under the age of 17 and there is a long list of contraindications and other issues that limit the number of potential candidates. Adipex (Phentermine) is more commonly used as it is widely tolerated, safe for consumption at aged 16 and above, and more effective.

If you are dependent on drugs or alcohol, you have a history of heart disease or hypertension, or you are pregnant/nursing, then you are not a good fit for either drug. You may be rejected if you have a family history of heart problems and have had issues with hypertension or palpitations yourself, or if you have a history of drug or alcohol dependence, as this increases your potential for abuse.


For more on Phentermine 37.5mg, please contact today.

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Phentermine is the best working weight loss pill I have used.

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Attention DrToHelp Patients

We want to thank you for your trust and business with, over the last 10 years! However, due to State and Federal laws, we no longer will be able to ship actual pills to you starting December 1, 2023. From this date on, we will only be able to send an electronic prescription to your pharmacy of choice, for you to go directly to your pharmacy to pick up your Phentermine pills there at your own pharmacy. 

We also will not be taking any NEW patients in Georgia, Indiana, Michigan, New York, Pennsylvania and Nebraska for the next 1-3 months.