The debate about the future of the weight loss drug Xenical is heating up following revelations made by some researchers that it could cause pre cancerous colon lesions in animals after extensive testing. The research was presented by a consumer group called Public Citizen which filed a petition to the American Food and Drug Administration saying that the application to allow Alli (a lower dose version of Xenical) should be rejected outright.

The FDA has given GSK the conditional approval to release the diet drug over the counter and without a prescription subject to the results of certain further tests. Public Citizen said that Xenical should be banned and Alli should not be released over the counter as these drugs could cause increases in teh amount of cancer cases. Public Citizen referred to a study that showed that orlistat (the key ingredient of both Xenical and Alli), may be the reason for abnormal cell growth in colon's lining which are generally regarded as the first steps to cancer in the colon.

The research was done on rats that were given high fat and normal diet along with doses of Xenical and they all got a big increase in the cancerous colon lesions. On the basis if this research the consumer group felt that it is unadvisable for the over the counter version of Orlistat to be approved and sold. At this point in time the GSK has not responded to the claim.

Xenical is sold in tablets of 120mg which are supposed to be swallowed three times daily at mealtimes, the new version called Alli that is up for review is a 60mg tablet and 1 or 2 can be swallowed with meals. It is identical to Xenical in everything except the dosage. Orlistat is a compound that stops the fat in food from getting absorbed out of the digestive tract and so the fat comes out of you untouched. The side effects are however that you get alot of flatulence and oily stools.

The report submitted by Public Citizen also spoke of Xenical being possibly responsible for cases of breast cancer  and information had been previously submitted to the United States FDA about this. There is also research that shows that being overweight can increase the incidence of all cancers and even cancer of the colon so by approving a weight loss drug may reduce the overall incidence of cancer. Public Citizen was of the opinion that further research and tests needed to be done before the widescale promotion of Alli as an over the counter drug.