Garcinia Cambogia Extract

 became popular worldwide after being featured on the Dr. Oz show in 2012.It is a small, green fruit, shaped like a pumpkin.The skin of the fruit contains hydroxycitric acid (HCA). This is the active ingredient in garcinia cambogia extract, which is marketed as a diet pill.
       How it works: Animal studies show that it can inhibit a fat-producing enzyme in the body and increase levels of serotonin, potentially helping to reduce cravings.
       Effectiveness: One study with 130 people compared garcinia against a dummy pill. There was no difference in weight or body fat percentage between groups .
       A 2011 review that looked at 12 studies on garcinia cambogia found that, on average, it caused weight loss of about 2 pounds (0.88 kg) over several weeks .
Side effects: There are no reports of serious side effects, but some reports of mild digestive problems

Raspberry Ketone

ketone is a substance found in raspberries, which is responsible for their distinct smell.A synthetic version of raspberry ketones is sold as a weight loss supplement.
       How it works: In isolated fat cells from rats, raspberry ketones increase breakdown of fat and increase levels of a hormone called adiponectin, believed to be related to weight loss .
Effectiveness: There is not a single study on raspberry ketones in humans, but one rat study using massive doses showed that they reduced weight gain .
       Side effects: They may cause your burps to smell like raspberries.
-- Kris Gunnars, BSc, “12 Popular Weight Loss Pills and Supplements Reviewed”Authority Nutrition