Green Coffee Extract - Dr OZ Recommended weight loss supplement. In a recent show named "Five Fastest Fat Burners," Oz called the green coffee bean a "magic bean" and the fastest fat burning supplement you can buy. A new study suggests taking green coffee bean extract, which is sold as a supplement in the United States, could be a safe and effective way to drop some pounds. Researchers gave up to 1,050 milligrams of green coffee bean extract to 16 overweight adults in their 20s and monitored their diet, exercise regimen, weight, heart rate and blood pressure for 22 weeks. Without changing their diet or exercise, study subjects lost roughly 10.5 percent - an average of 17 pounds - in overall body weight. No harmful side effects were noted, according to the study presented today at the American Chemical Society national meeting in San Diego. How green coffee bean extract contributes to weight loss is unclear. But Vinson theorizes a chemical in the unroasted bean called chlorogenic acid could be responsible. Other experts suspect the stimulant properties of caffeine could be the culprit. Dr. Oz says, green coffee bean extract can help you lose weight. This "magic bean" is one of the fastest fat burning supplements. It's incredibly powerful and best of all it's safe.