We’ve put together a list of frequent questions we receive below. This page is periodically updated so check back from time to time for the latest Q & A. Clicking on a question will expand it and the answer will then be visible.

Why was Phentermine created?
It was created as a means to assist patients who are diagnosed with obesity by their doctors. It is not a wonder drug and is usually prescribed alongside a diet and exercise plan.
How long does Phentermine usually work?
Phentermine was meant to be a temporary solution to obesity and works per each dose. Due to the variations in the chemical composition of each person, it’s hard to predict exactly how long it will take for Phentermine to become ineffective after prolonged use.
Are there any side effects associated with Phentermine that I should know about?
As with most Rx medication, Phentermine does come with a painful price. Side effects such as the following have been reported by users:

  • Diarrhea
  • Depression
  • Addiction
  • High blood pressure
  • Rash outbreaks
  • Decreased libido, and more.
Where can I buy Phentermine?
Currently Phentermine is only available via your doctor. The FDA has deemed it unsafe for unsupervised consumption as it is very similar to amphetamines, therefor it is classified as a controlled substance.
Do I need a prescription from a doctor to obtain it?
As stated in the previous question, yes. It is highly advised not to take Phentermine without the supervision of a certified professional.
What milligrams are available?
This weight loss medication is available in 37.5mg, 30mg, and 15mg strengths.
What is the recommended dosage?
The recommended daily dose for Phentermine can vary slightly based on each individual. When your doctor prescribes you with this medication, he will normally administer the least amount that is needed based on your personal situation.

Typically doctors like to start with a 15mg dosage, but at times, may skip that and go straight to the 30mg.

Doses are in the following ranges:

  • One x 15 milligram tablet or capsule
  • Two x 15 milligram tablets or capsules usually taken in the morning and right after lunch.
  • Two x 18.75 milligram tablets or capsules usually taken in the morning and right after lunch.
  • One x 30 milligram tablets or capsules
  • One x 37.5 milligram tablets or capsules
  • One and a half x 37.5 milligram tablets or capsules – one whole usually taken in the morning and the remaining half after lunch.
How long can I safely take Phentermine pills?
This medication is very addictive and is known to be highly habit forming. Therefore, don’t be surprised when you doctor only limits you to a 90 day prescription period – which is the recommended time frame.
If I take Phentermine will it show up in a drug test?
Possibly. Given that this weight loss medication is chemically similar to that of amphetamines, if the drug test screens for amphetamines then it very well may show positive.
How long has Phentermine been around?
It was first developed in the late 1950’s and has been available in the US since the 1960’s. Our timeline infographic lists all of the notable dates since Phentermine’s existence. You can see it here
What is Qsymia?
Qsymia (formerly known as Qnexa) is a Phentermine combination pill consisting of Phentermine Hydrochloride and Topiramate. This drug was approved by the FDA in July of 2012. More information on Qsymia can be found here
What is Fen-Phen?
This is yet another combination Phentermine drug. The Fen is an abbreviation for Fenluramine, while the other Phen is short for Phentermine. Being that this combination proved to be more effective than Phentermine alone (based on studies conducted by Dr. Michael Weintraub back in ’92), it quickly became very popular nationally resulting in roughly 6.6M prescriptions in 1996 alone. More on this can be found in our history infographic as well.
What is Phen-Pro?
Phentermine + Prozac = Phen-Pro. One would think that the purpose of this cocktail would be to lose weight while suppressing depression, however that’s not the case with Phen-Pro. By adding Prozac (or Trazadone, Zoloft, or Celexa) to Phentermine, it allows the patient to use the medication for an extended period of time beyond that of Phentermine alone while maintaining the effects at their peak.

It is important to note that this combo has not been approved by the FDA.

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