Top 10 Medical Breakthroughs

#4. Help for Dieters: Alli

Need help shedding those extra holiday pounds? Overweight adults now have an extra weapon against fat: Alli, the first FDA-approved weight-loss drug sold over the counter. Alli (a.k.a. orlistat) works by monkeying with lipase, an enzyme the body uses to break down and digest the fat in food. A dose of Alli (pronounced like ally) on the heels of a meal blocks the body's ability to absorb fat by 30%. But Alli's maker, GlaxoSmithKline, insists the drug isn't a magic bullet and recommends that it be used only in conjunction with a healthy low-fat diet and plenty of exercise. Another reason to practice a little restraint? Sticking to a low-fat diet helps reduce Alli's common and unpleasant side effects — cramps, gas, diarrhea and oily discharge.

Connect to this TIME Story