The facts about our prescribed medication: Phentermine and Diethylpropion 

  • Up to 5% of all Phentermine / Diethylpropion drugs used in the UK are prescribed by the NHS and dispensed through high street chemists
  • The primary concern of OMA registered clinics is patient safety in accordance with General Medical Council (GMC) guidelines
  • Each patient at an OMA registered clinic is the responsibility of a GMC registered doctor
  • In most cases consultations at an OMA registered clinic, including prescribed medication, costs less than buying the same drugs illegally on the internet
  • Unlike other available anorectics there have been no fatalities recorded as a result of prescribing Phentermine or Diethylpropion
  • European Courts have upheld the safety and efficacy of Phentermine and Diethylpropion
  • Neither drug is addictive or connected to amphetamines

Frequently asked questions about Phentermine and Diethylpropion

How effective are Phentermine and Diethylpropion?

OMA registered doctors and clinics prescribe in excess of a million effective treatments per year improving the life style and well-being of their patients through weight management and weight loss programmes.

Are the drugs safe?

Both drugs have been licensed and used by the NHS in the UK for more than 50 years. During this time more than one billion patient treatments have been dispensed. The Committee on Safety of Medicines has advised that, as with Amfepramone, there are no major public health concerns in relation to Phentermine and Diethylpropion products remaining on the UK market.

Both drugs are licensed by the Medicines and Healthcare products Regulatory Agency (MHRA) and as such are only available on prescription from a GMC registered doctor. OMA insists that Members fully comply with the terms of the said Licences and implement standard clinical practice requirements relating to each patient’s medical history and current health in order to determine a patient’s suitability to be prescribed any medicines

What is the European Union’s stance on anorectic agents (appetite suppressants)?

On the 26th November 2002, The European Court of First Instance found that the EU had failed to prove their allegation of a lack of efficacy. Efficacy had been proven when the Medicines Control Agency (MCA*) originally registered these medicines in 1950.
The court also found that no new safety concerns had been proven since the EU review of the safety data in 1996.
These decisions establish that:

  1. Diethylpropion and Phentermine are safe in normal use.
  2. Diethylpropion and Phentermine are effective in normal use.

Throughout this period both drugs were and remain available and licensed by the MHRA.

*The Medicines Control Agency joined with the Medical Devices Agency to become the Medicines and Healthcare products Regulatory Agency

Is Phentermine in any way similar to an Amphetamine like drug?

In a report published by the Medicines Commission Agency in October 1995 they concluded that the term Amphetamine-Like unjustifiably caused confusion as the only similarity is the chemical structure. There is no pharmacological connotation between Phentermine and any amphetamine based drug. A simple analogy is that water has a similar chemical structure to Vodka – but the pharmacological impact and effect are entirely different.

What is the position of UK Law on the purchasing of Controlled Drugs?

The law states that a doctor is authorised to order, possess and prescribe all controlled drugs.  Nowhere does it state that they have to purchase them so providing the doctor orders them in a legal manner either on a signed order or prescription, they can make the payment any way the y like. Or put another way, the law does not say they have to purchase them, only to order them in a legal manner.

Is Phentermine in any way addictive?

Research indicates there are no authoritative reports that state Phentermine is addictive. Furthermore, the clinical licence stipulates a 12 week cycle of treatment. No GMC registered doctor would prescribe an addictive drug knowing the treatment cycle was limited to 12 weeks.

Does Phentermine contribute to Valvular Heart Disease?

There is no clinical or medical evidence to support the statement either drug contributes to Valvular Heart Disease.

A report by Dr Gary Glazer of the University of Rochester School of Medicine and Dentistry, Rochester, published in the Archives of Internal Medicine on research into the Long-term Pharmacotherapy of Obesity 2000 (Arch Intern Med. 2001;161:1814-1824) conducted in the United States shows that anorectic medications such as Phentermine are not associated with increased risk of VHD as defined by the Federal Drug Administration.

In addition - in a landmark legal action in the United States, the results in the case of Linda Eichmiller vs. American Home Products, et al. the jury returned a unanimous verdict in the Company's favour (Nov 2003) on the basis that there was insufficient information to suggest an association between diet drugs and valvular heart disease.

Does Phentermine contribute to Primary Pulmonary Hypertension?

In not one single case of Primary Pulmonary Hypertension (PPH) worldwide has there been any clinical based evidence to attribute the cause to Phentermine.

The New England Journal of Medicine states:

 “PPH is usually a very rare disorder with an annual incidence of 1-2 cases per million people. It is noteworthy that in a study in 2000 that no link was found between Phentermine and PPH…. There is currently no systematic scientific evidence for an increased risk of PPH in patients receiving Phentermine alone

Are there any side effects?

The Medicines Commission Report, published in October 1995, in which the Commission considered the safety profile of centrally acting appetite suppressants, concluded that side effects are generally minor, self-limiting and of no serious consequence. The frequency of these side effects has consistently been reported to be very low.

Should ‘Best Practice’, as stated by NICE / The Royal Colleges / other Agencies supersede UK Law on Medicines and a doctor’s ability and freedom to practice?

Proposed or stated best practice should not automatically be accepted as the law. The guidelines and opinions of the Royal Colleges, the BNF, NICE, HCC, and others are to be respected – but as guidelines or opinions they cannot be used against a doctor or clinic to enforce, change or support a legal or other case against the doctor or clinic.

All directions and actions required of you, by any agency, must be presented in writing.  Anyone has the right to automatically access their files under the Freedom of Information Act.