How Does Hoodia Work?

Physically

A molecule in Hoodia, known as P57, is believed by some scientists to make people feel full. Normally, when you eat, your glucose level rises and sends a signal to the hyothalamus in the brain that you have eaten enough. Hoodia is believed to work by imitating the effect of glucose. It sends the "full" signal, inhibiting the physical desire to eat. A study in the United Kingdom by pharmaceutical company Phytopharm showed that subjects who took Hoodia consumed less calories than those who took a placebo, even though unlimited amounts of food were available (see Resources). However, there were only 18 participants in the study, so it does not necessarily prove Hoodia's effectiveness.

Emotionally

Although Hoodia doesn't have a direct effect a person's emotions, its physical effects can help her break her emotional attachment to food. Overeating often becomes habitual. When a person is stressed, sad or bored, she reaches for a snack without conscious thought. By giving her a "full" feeling, Hoodia helps to break this cycle. In the Phytopharm study, participants were given very few activity options. They only allowed to watch television, read or sleep. Even with these limited and sedentary options, they still ate an average of 1000 fewer calories per day.

Dose and Purity

For Hoodia to work properly, a person must take a high enough dose, which is usually at least three grams per day, and use a genuine product. Due to the popularity of Hoodia, some unscrupulous sellers have sold pills that actually contain sawdust or other fillers. People who are tricked into buying counterfeit pills may believe that Hoodia doesn't work when not really taking it at all.

The Placebo Effect

Even though Hoodia appears to have a real physical effect on weight loss, it may also have a placebo effect for some people. The effectiveness of the placebo was shown in a 2008 study by Harvard psychologist Ellen Langer, who told one group hotel maids that the amount of physical exertion they were getting in a day's work should be enough to cause them to lose weight. A control group doing the same amount of work was not told anything (see Resources). During the study, the first group lost inches and lowered their blood pressure. In the same way, if a person truly believes that Hoodia will work, they may eat less because of that belief.

Resources

• Hoodia study information
• Placebo study