Herbal Medicine For Weight Loss

Certain herbs have gained a reputation as being capable of promoting weight loss. However, little scientific evidence exists showing that any herbal medicine for weight loss is effective. In addition, some herbs touted for weight loss can produce side effects. If you need to lose weight, consult your health care provider before self-treating with herbal supplements. This is particularly important if you have a chronic condition or are taking other medications.

Theories/Speculation

The mechanisms behind herbal medicines to increase weight loss typically involve one of three pharmacological effects. The phytochemicals in plants may possess diuretic properties, which means they increase urination. Other plant chemicals speed up the metabolism by stimulating the thyroid gland or central nervous system. Other herbs contain agents that trick the body into feeling full by increasing brain chemicals that initiate a "feel good" response, such as serotonin.

Some weight loss herbs produce an increase in bowel movements with reduced transit time between the gut and colon. It should be noted, however, that these actions result in more of a cleansing or detoxification effect than weight loss.

Specific Herbs

Until the U.S. Federal Drug Administration banned its sale as a dietary supplement in 2004, ephedrine was one of the most popular herbal medicines for weight loss. Ephedrine is obtained from ephedra, an herb known in Chinese medicine as ma huang. It is also an example of an herb that acts directly on the nervous system. In fact, ephedrine is a precursor to methamphetamine, a street drug commonly known as "speed" or "crank."

One herb currently marketed for weight loss is guggulsterone, a resin obtained from the guggul tree. The action of this herbal medicine is to stimulate the thyroid to increase metabolism and the burning of fats and calories. Similarly, yerba mate is attributed with thermogenic effects due to the presence of stimulants, namely caffeine, theobromine and theophylline. Diuretic herbs, such as dandelion, are also found in over-the-counter herbal weight loss supplements.

Clinical Evidence

According to a review published by the research division of the RAND corporation, studies have shown that ephedrine derivatives may promote modest weight loss, but with short-term benefits and potentially long-term health complications, including coronary and psychiatric events. Evidence on the efficacy of guggul as a weight loss aid is limited, although Drugs.com indicates that early studies have shown some weight loss potential of this herb in combination with other botanicals. According to D.P. Arçari, lead author of a study published in the Dec. 17, 2009, issue of "Obesity," yerba mate significantly reduces the number of adipocytes, or fat cells, in rats. The team of researchers also found that yerba mate compounds inhibit the expression of certain genes that regulate obesity.

Safety Considerations

Stimulants found in weight loss herbs are known to produce side effects and interact with other drugs. For instance, according to a study published in the August 2004 issue of the "Journal of Pharmacology and Experimental Therapeutics," guggul compounds increase the production of a liver enzyme that reduces the effectiveness of anti-coagulant, HIV and chemotherapy drugs. The RAND review reports that ephedra compounds are associated with an increased risk of stroke, seizure and heart attack. According to the Cleveland Clinic Foundation, yerba mate may increase the risk of lung, kidney, bladder and oral cancers.

Summary

The Cleveland Clinic cautions that herbal medicines for weight loss do not produce long-term results. However, long-term use may increase the risk of toxicity and dependency. These products should not be used during pregnancy, while nursing, in conjunction with other medications or if you have a chronic disorder. If obesity is an issue, ask your health care provider to help you design a weight loss program that includes a balanced diet and regular exercise.