The ingredients in Stacker Fat Burners vary slightly from product to product but two ingredients that do not change are caffeine (either from guarana or kola nut) and willow bark (aspirin). Fat Burners are still available with ephedra, but you will pay up to 5 times more for them and the ephedra-free Stacker Fat Burners products are just as effective.

Stacker 2 and 3 contain 25 milligrams of ephedra – taken from the Mahuang plant. Ephedra has long been used as a bronchodilator, but it also speeds the metabolism. When taken responsibly, Stacker 2 and Stacker 3 with ephedra are very effective workout boosters and appetite suppressants. The key word is “responsibly”. Read the label and follow the directions precisely. Depending on where you live, Stacker with ephedra may not be available. Because of the recent bans on ephedra, these are much more expensive than the ephedra free formulas.

Stacker 3 adds an ingredient not found in 2. Chitosan is derived from shellfish and should never be used by anyone who has an allergy to shellfish. Lab tests show that Chitosan blocks fat and cholesterol from being absorbed by the body in laboratory animals. While the FDA has not evaluated its effects in humans, many people who use Stacker with Chitosan swear by its benefits.

Populair stackers are Stacker 2 and 3, they are both available in ephedra free formulas. Instead, they contain citrus aurantium or “bitter orange”, a replacement for ephedra that is purported to have the same effect without the dangers of ephedra. Green tea is another ingredient added to the Stacker. It is not only for the caffeine. Green tea has been shown to increase metabolism, burning as much as 25 extra calories per cup. The green tea in Stacker is meant to do the same thing. Green tea is also high in antioxidants, which adds an element of health benefits to the formula.

The latest Stacker ( Stacker 3 XPLC and Stacker 4) contain thermogenic ingredients to assist those who have slow metabolisms and have the most difficult time trying to lose weight.