Bitter Orange, Citrus Aurantium, and Sour Orange: These products are made directly from concentrated extracts from orange peel. They often claim that they increase metabolism, but there has been no conclusive tests to back this up. Bitter Orange, Citrus Aurantium, and Sour Orange contain the stimulant synephrine, which can cause hypertension and cardiovascular toxicity. Individuals with heart disease, hypertension, and glaucoma should avoid these at all costs.
Chromium (Examples of Chromium products include Puritan’s Pride Chromium Picolinate, Vitamin World Naturally Inspired Yeast Free Chromium Picolinate, Nutrilite Trim Advantage): The claims that chromium increases weight loss and improves body composition have been backed by one main study which proved this to be the case. There are two types of chromium: Trivalent (which the body requires and is considered safe in doses of 200 micrograms or less daily) and Hexavalent (but this form can cause stomach upsets, ulcers, convulsions, kidney and liver diseases, and death).
Conjugated Linoleic Acid (CLA) (Examples of this product include Vitamin World CLA, Nature Made CLA, Now Foods CLA): This product claims to promote leanness, but there are very few studies that actually support the marketing claims. While more research is needed, CLA is generally safe.
Ephedra/Ephedrine: Ephedra may aid weight loss by suppressing appetite, and research has proven its effectiveness when used with caffeine. However, ephedra causes high blood pressure, stroke, and serious heart problems, which is why the sale of dietary supplements containing ephedra was prohibited in April 2004.
7-Keto Dehydroepiandrosterone (7-keto DHEA): Preliminary research indicates that this product may decrease body weight and fat composition by increasing metabolism, but larger research studies are needed.
Hydroxycitric Acid (HCA) and Garcinia Cambogia: These products claim to suppress appetite and improve fat metabolism. While studies have shown mixed results, they are generally safe.
L-Carnitine: L-Carnitine claims to inhibit obesity, but there is very little evidence of its effectiveness.
Dihydroxyacetone (DHA), Pyruvate, and Dihydroxyacetone and Pyruvate (DHAP): A few small studies suggest that these supplements may have modest effects on weight loss, but research is needed. Presently, no serious side effects have been reported.
Lecithin, Guar Gum, Psyllium Hulls, Chickweed, and Chitosan (Examples: Chito-Trim, Exercise in a Bottle, Fat Blocker—Chitosan Complex, Fat Grabbers, Fat Trapper, Fat Trapper Plus, Metabo Fat Blocker, Miracletab, Now Chitosan with Chromium): These products claim to help break down fat so that it can be absorbed, emulsified, trapped, and eliminated by the body. There is currently no competent and reliable scientific research to support such claims.