Many manufacturers offer weight loss products containing green tea extract and hoodia. While research shows that both of these supplements may contribute to a weight loss program, neither has been approved by the U.S. Food and Drug Administration for weight loss. Additional clinical studies are needed to conclusively prove or disprove claims made by weight loss supplement manufacturers.
Clinical studies suggest that green tea may boost your metabolism and aid your body in burning fat. According to Rebecca Dobler of Vanderbilt University, green tea promotes heat production, or thermogenesis, in the cells, enhancing energy expenditure and stimulating weight loss. Additionally, green tea may inhibit the digestion of fat in the intestines, according to the University of Michigan Health System.
Many varieties of hoodia exist, but only the rare Hoodia gordonii contains the active ingredient thought to suppress appetite, reports Melissa Divack of Vanderbilt University. This active ingredient, a steroidal glycoside now known as P57, seems to affect the hypothalamus, which regulates hunger and fools your brain into thinking you're full for up to 24 hours. However, claims that hoodia effectively suppresses appetite are not supported by any solid evidence, warns MayoClinic.com. Also, the rarity of the hoodia botanical has prompted some less than reputable manufacturers to advertise hoodia weight loss products that don't actually contain any hoodia.
Several cases of liver damage have been reported by individuals using weight loss products that contain green tea. Although a cause and effect relationship has yet to be determined, researchers advise against taking concentrated green tea extract in large doses.
Green tea contains caffeine, which causes the most common side effects of the supplement. If you experience anxiety, insomnia, restlessness or tremors, consider using a decaffeinated green tea extract.
People who have diabetes should avoid taking supplements containing hoodia. Because hoodia blocks the normal warning signs of hunger, it could allow for a very dangerous drop in blood sugar. Hoodia could also be extremely dangerous for people with eating disorders or extreme dieters.
Although herbal supplements have been used for centuries to strengthen and heal the body, they contain active compounds and substances which can cause adverse side effects and may interact or interfere with other medications, supplements or treatments. Talk to your doctor prior to beginning any supplement program to ensure your safety and health.
- University of Michigan Health System: Weight Loss and Obesity
- Vanderbilt University Health Psychology: The Health Benefits and Weight Loss Secrets Behind Green Tea
- Vanderbilt University Health Psychology: Hoodia and weight loss
- Mayo Clinic: Is hoodia an effective appetite suppressant?
- University of Michigan Health System: Green Tea