With sales of over-the-counter diet pill alli (low-dose Xenical) now in their third week, reports from around the country seem to indicate the diet drug had a strong launch -- but is perhaps not racking up the blockbuster sales that GlaxoSmithKline had hoped to see.

While some stores on opening day quickly sold out of their allotment of the first non-prescription weight-loss drug ever approved by the FDA, shelves for the most part have been restocked and alli seems readily available at most supermarkets, pharmacies and big retailers around the country.

One thing that may be putting a damper on sales is the fact that a month's supply, a container of 90 tablets, costs between $60 and $70. Because of the cost, some retailers are selling alli from locked cases or from behind the pharmacy counter.

As the initial buying frenzy driven by Glaxo's pre-launch marketing campaign slows, pharmacists also report many shoppers seem to be weighing the help alli can give them in losing weight against the cost and alli's well-publicized unpleasant side-effects.

Glaxo says alli in conjunction with a reduced-calorie, low-fat diet and exercise program can help dieters lose 50 percent more weight than they would otherwise (ie, 15 pounds instead of 10 pounds), but that intake of more than a minimal amount of fat is likely to result in a gaseous or oily outake (or worse).

As even Glaxo is quick to concede, the drug can cause flatulence, oily discharge, and uncontrolled bowel movements if you eat too much fat.

Kelly Brownell, who directs the Yale Center for Eating and Weight Disorders, told the Philadelphia Inquirer he felt "sales will tail off fairly quickly."

"Both the benefits and the side effects are overstated," Brownell said. "It's not going to hurt many people, and it's not going to help many people.

"The people who will try it won't lose much weight, and won't provide very good word-of-mouth," he added.