Glaxosmithkline announced June 12 that the first over-the-counter weight loss pill ever sold in the United States will be available later this week under the trade name Alli, which is manufactured by Roche, but marketed by Glaxo.

Alli is made of the same chemical orlistat as its prescription counterpart xenical.  The chemical was approved in 1999 as a weight loss agent and xenical has been available for years as a prescription drug.   The only difference is the dose, 60 mg in alli versus 120 mg in xenical.

Alli as an OTC medication was approved by the Food and Drug Administration in February 2007.  The FDA advisory committee voted 11 to 3 early last year to recommend that FDA approve the drug for OTC sales.

The FDA says on its website, "Alli is to be used only in conjunction with a weight loss program that includes a reduced calorie diet, low fat diet and an exercise program."

By definition, low fat diet consists of 30 percent calories from fat.

Glaxo agrees that alli is no magic weight loss pill and people should not expect results overnight.  In trials, weight loss was only observed in those who followed instructions on the whole program.

In a 6-month trial, people with excess weight who took three capsules of alli a day lost 5.3 to 6.2 pounds as reported last year by foodconsumer.org .  50 percent of participants experienced the effect, compared to 26 percent among those taking a placebo.

The lost weight will come back if the program participants stop taking alli. Those who wish to keep the lost weight off need to keep taking the medication.

But due to the safety issue and the fact that the long term effect of alli remains unknown, the drug should not be used for a period of more than six months.

Alli helps weight loss by blocking fat absorption. Because of this, users of the drug are at risk of malnutrition as they can not adequately absorb fat-soluble nutrients or vitamins such as vitamin D, E, K and beta-carotene.  

The FDA reminds patients in a statement published on its web site that they should take a multivitamin while using alli.

Alli is indicated for adults age 18 or older.  But certain groups of people may not attempt to use it as it may potentially cause malnutrition.   It should not be used by people who have problems absorbing foods or gallbladder problems and women who are pregnant or are breastfeeding.

Although trials did not show any major adverse effects, meaning it is generally safe, use of alli can cause some embarrassing side effects such as causing gas with discharge, oily discharge, increased number of bowel movement, oily spotty, oily or fatty stools, urgent need to have a bowel movement and inability of controlling bowel movement.

These side effects can be more significant among those who do not stick to a low fat diet. Because of this, Glaxo recommends patients use dark underwear.

The worse concern that the drug may increase cancer risk came from Public Citizen, which filed a petition to the FDA asking the agency to ban alli and its "siblings" as they labeled the drug as junk medication.   But the FDA denied the petition, obviously.

Dr. Sidney Wolfe of the consumer organization said early that animal studies by Roche, which make the drug, show that the chemical used in alli caused cyptic loci, precancerous lesions in the colon in rats.   But some experts disputed the concern.

While weight loss is slow, moderate or even temporary, alli is costly to some people. 90 capsules may cost $12 to 25 a week, according to early news reports.  This means to lose 5.7 pounds in six months, patients need to pay $300 or more, about $50 per pound.

To have a weight loss effect, taking alli is not the only thing that needs to be done.  Patients need to follow the whole program including a restrictive diet and physical exercise.   Glaxo said early that it will provide consumers a 250 page instruction when they purchase alli.

Many people are skeptical of the efficacy of alli.  Cheryl Truman, columnist at kentucky.com suggests dieters should rely on diet and physical exercise to lose weight in a healthy way, but not alli, which results in a temporary, moderate effect while its long term side effects remain unknown.

A scientist affiliated with foodconsumer.org suggests that those who can't afford time and or money for alli may drink one glass of water or two before each meal, which can at least theoretically help reduce intake of calories and lose weight.