Fat Blocker FB500 capsules are triple action capsules :

Action 1
Information about the ingredients :
Chitosan, derived from shellfish. Once activated in the stomach, Chitosan binds to fatty acids, which are the primary components of dietary fats. Because the body cannot digest Chitosan molecules, the fatty acids that are bound to the Chitosan and are eliminated from the large intestine without being absorbed by the body. Combined with Vitamin C for enhanced absorbtion, and Gynmenna Sylevestra to promote blood sugar stabalization and HCA to help aid in transporting fatty tissue. In a recent clinical study in Helsinki, the results were more pronounced. An average of 8% of TOTAL body weight (15lbs pp) was lost in a 4 week period with Chitosan supplementation. Chitosan has also been proved effective at reducing cholesterol. Studies have shown cholesterol reduction of up to 32% over a 5 week period. At the same time Chitosan appears to moderately increase HDL (good) cholesterol, which keeps the arteries free of athersclerotic plaque.!

Action 2
Gymnema sylvestre is an Indian herb, from which gymnemic acid is derived. Research has shown it to have a number of positive benefits for weight control and health, showing to play a role in blood sugar regulation, a reduction in sugar cravings, regeneration of the pancreatic insulin-producing cells (doubling) and reversal of pathological alterations of the liver, kidney and muscle tissue as a result of hyperglycemia*. There are no side effects with this herb. * Baskaran K, Kizar Ahamath B, Radha Shanmugasundaram K, Shanmugasundaram ER; Antidiabetic effect of a leaf extract from Gymnema sylvestre in non-insulin-dependent diabetes mellitus patients; J Ethnopharmacol. 1990 Oct; 30(3): 295-300. Brala PM, Hagen RL.; Effects of sweetness perception and caloric value of a preload on short term intake; Physiol Behav. 1983 Jan; 30(1): 1-9. Shanmugasundaram ER, Gopinath KL, Radha Shanmugasundaram K, Rajendran VM; Possible regeneration of the islets of Langerhans in streptozotocin-diabetic rats given Gymnema sylvestre leaf extracts; J Ethnopharmacol. 1990 Oct; 30(3): 265-79. Shanmugasundaram KR, Panneerselvam C, Samudram P, Shanmugasundaram ER; Enzyme changes and glucose utilisation in diabetic rabbits: the effect of Gymnema sylvestre, R.Br.; J Ethnopharmacol. 1983 Mar; 7(2): 205-34.

Action 3
Rutin is a bioflavonoid or flavone that naturally occurs with vitamin C. It is found in buckwheat and fruit and may help to maintain the integrity of blood vessels and maintains your metabolism. 

Cautions
As with any food supplement you should seek the advice of a qualified heath care practitioner if any of the following conditions apply: you are on prescription drugs; have prostrate enlargement; diabetes; heart or thyroid disease; high blood pressure; or are pregnant or breast feeding. Some people like to consult their doctor before taking any new food supplement.

Are there any side effects?
There are no known negative side effects.