CR's Take
		The prescription fat-blocking drug orlistat (Xenical) is now available in a lower-dose over-the-counter version under the brand name Alli. But it offers modest results and can cause embarrassing side effects, so you might be better off skipping the pills and saving your money.

It's no longer convenient to purchase an effective decongestant these days, now that pseudoephedrine has been moved behind the counter. But if it's weight loss you're after, you can now buy orlistat, a fat-blocking drug of limited effectiveness, with ease. In February the Food and Drug Administration gave manufacturer GlaxoSmithKline the green light to sell an over-the-counter version of the drug under the brand name Alli. Alli is half the dose of prescription orlistat, Xenical, which has been on the market since 1999.

With the move GlaxoSmithKline stands to snag a chunk of the $41 billion that Americans spend on weight-loss strategies each year. The company says Alli, which recenly hit store shelves, will cost $1.80 per day.

But if a pill that limits your body's ability to absorb fat from food seems a little too good to be true, you're on to something. The drug has several drawbacks.

For one, Xenical hasn't lived up to its promise; some doctors have found it to offer marginal benefit in clinical practice. At half the prescription strength, Alli is likely to be even less effective. Data presented to the FDA suggest that Alli works best in those who are very overweight, that it must be used in conjunction with a low-fat, reduced-calorie diet, and that results are modest. In clinical trials, severely overweight subjects who took the drug for six months lost about 5 pounds more than those taking a placebo. In a separate four-month trial, moderately overweight people lost about 2 1/2 pounds more than the control group. Benefits are also likely to be short-lived. Alli is marketed for short-term use only, and follow-up suggests that people start to regain weight once they stop taking it.


Embarrassing side effects

Orlistat is notorious for what one FDA advisory panel member termed "the underwear problem." Unabsorbed fat can cause intestinal side effects such as fatty stools, oily spotting, flatulence with discharge, an urgent need to defecate, and frequent bowel movements.

Evidence suggests that the drug can also impede the absorption of fat-soluble vitamins. Users need to take a multivitamin daily at least two hours before or after taking orlistat, though in actual-use studies only about half managed to do so. Orlistat should not be used by those taking the blood thinner warfarin (Coumadin). People on diabetes medications should use it only under a doctor's supervision.

GlaxoSmithKline is including a guide to healthful eating and free access to an individualized online action plan with Alli starter packs. But while the advice might be worth taking, the pills might not be.