There’s a new over-the-counter weight-loss drug hitting the market today, but you might want to think twice before rushing to Walgreens :

The new pill is called Alli. Taken three times a day with a low-calorie, low-fat diet, doctors said you’ll lose weight. But if you eat food high in fat, you’ll feel it.

“It’s conditioning. It’s like if you eat this stuff, you’re going to have an unpleasant toilet experience,” Dr. Konoy Mandal with Research Medical Center said. “It’s not going to sound good, it’s not going to look good and you’re not going to be very popular in public.”

Alli works by preventing fats from being absorbed in your body, but doctors said it can leave you with some very embarrassing bowel movements.

“Buy some extra underwear,” Dr. Mandal said. “You’re gonna have some events.”

Under the drug facts on the back of the package, the manufacturer said gas with oily spotting and loose stools are part of the treatment effects.

“Genius marketing,” Dr. Mandal said. “Treatment effects…instead of like farting and pooping explosively.”

One of the nice side-effects of the drug is that it also acts as an appetite suppressant. All you have to do is read the warning label before eating.