Worldwide there are almost 2,300 websites selling weight loss pills, with a global market of over ?30 billion. However, many of the weight loss pills that you will find on the internet contain ingredients that have been banned around the world.

This is an unregulated Wild West market - in reality you have no idea what you are actually buying. This raises two issues - are they safe, and are they effective. Recently a laboratory tested a variety of brands of Hoodia weight loss pills, and found that less than 50% actually contained any Hoodia!

Safety is also a big issue. Here are some of the drugs to look out for if you are thinking of buying weight loss pills:

Amfepramone: Know as "diethylpropion" in the UK, this prescription only appetite suppressant was banned by the European Medicine Approval Agency in 1999 because of safety concerns.
Phenylpropanolamine: Not approved in the UK for the treatment of obesity, it is used in nasal decongestants and cough medicines.
Ritalin: Widely used for treating ADHD, Ritalin is not approved as a slimming aid. Side effects include increased heart rate and raised blood pressure.
Clenbuterol: Banned for use by athletes, Clenbuterol was developed as an asthma treatment, but it does seem to increase metabolic rate and help people to lose fat and gain muscle. Due to cases of poisoning linked to meat containing Clenbuterol, its use is strictly controlled.
Phentermine: Closely related to amphetamines, phenteramine stimulates the release of brain chemicals, which reduce sensations of hunger. Common side effects include mood swings, chest pain, tremors, irregular heartbeat, hallucinations, severe headaches, and seizures.