The magic bullet for obesity -- rimonabant (Acomplia) -- does help people lose weight, although not that much weight, and also helps lower cardiac risk factors, according to a review of studies.

The drug works in a new way, suppressing the appetite by targeting the brain cells involved in the "munchies" familiar to marijuana users.

"The use of rimonabant after one year produces modest weight loss of approximately 5 percent" of body weight, found reviewers led by Cintia Curioni, at the State University of Rio de Janeiro, in Brazil. "Compared with placebo, a 20-milligram pill produced a 4.9 kilogram greater reduction in body weight in trials with one-year results."

This translates to weight loss of a little under 11 pounds.

The review looked at four randomized controlled trials comparing Acomplia at two dosages and with placebo, after one or two years of treatment.

Participants, all overweight or obese, followed a "mild" low-calorie diet, adjusted for individual body weight.

Only the higher dose -- 20 milligrams -- had significant impact on weight, waist circumference, cholesterol levels and blood pressure.

However, the higher dose brought on more, and more serious, side effects than both the lower dose and placebo.

People on the larger dose lost an average 1.5 inches on their waistlines. They also showed a slight dip in blood pressure. The higher drug dose significantly lowered blood lipids (fats) and increased high-density lipoprotein ("good" cholesterol) by 3.5 mg/dl compared to placebo.

But on the flip side, side effects included nausea, dizziness, headache, joint pain and diarrhea. More serious side effects included psychiatric and nervous system disorders.

Rimonabant has been billed for several years as a potential panacea for the most troublesome of habits -- obesity, smoking and possibly alcohol addiction. Studies on its use in smoking-cessation studies are currently under way.