Some popular substances used for herbal weight loss include:
St. John's Wort (hypericum perforatum) supposedly encourages weight loss by curbing appetite. The herb is proved to interact unfavorably with a number of doctor-prescribed medications; the FDA has not approved St. John's Wort as safe for weight loss. Risks include allergic reactions, insomnia, gastrointestinal pain and fatigue.
Ephedra (Ma huang) is derived from ephedrine, a stimulant that is purported to suppress appetite. The FDA banned ephedra for human consumption in 2004 due to "concerns over cardiovascular effects including increased blood pressure and irregular heart rhythm."
Senna (Cassia angustifolia) comes from the bark of trees that fall within the Cassia classification. Senna is ingested for its laxatative properties; side effects include cramping and diarrhea.
Garcinia cambogia comes from the fruit of a 'tropical tree of Indian origin.' Diet products that include the substance claim it represses fatty acid synthesis and reduces appetite but medical studies show no increased weight loss between Garcinia cambogia and a placebo.
Hawthorn (Crataegus sinaica) supposedly possesses diuretic properties; diet product manufacturers also claim it lowers cholesterol, boosts metabolism and reduces fat. The FDA is pursuing these claims as false, saying it has " no information that these products are generally recognized as safe and effective."
Ginseng (Panax quinquefolium) is one of the most forms of herbal weight loss; reported to stimulate metabolism and energy, research has found it increases blood pressure and can cause problems in those with hypertension and heart disorders.
Ginkgo biloba comes from the Chinese Ginkgo tree; reported to aid in circulation and boost metabolism, Ginkgo biloba should not be used by people taking anti-depressants, have a blood clotting disorder or by pregnant women. May cause bleeding, headaches and vomiting.
Willow bark (salix) is similar to aspirin and is used to help dieters feel better in general; according to the FDA, ingestion by children can lead to Reye syndrome, "a potentially fatal disease associated with aspirin intake" and may cause allergic reactions in adults.
Yerba mate (Brazilian tea) is advertised as 'a natural appetite suppressant and energy booster.' Yerba mate contains large amounts of caffeine, which increases your heart rate and can lead to headaches and problems in those with high blood pressure.
Consult your physician before consuming any product designed to help you lose weight. Remember, herbal weight loss might work for you, though there is a significant lack of hard scientific evidence proving so.