Name That Tea

Most teas we drink come from the same plant, Camellia sinensis. So how does one plant produce so many types of tea? It all has to do with the way the leaves are processed after picking. To make black tea, leaves are allowed to ferment, or oxidize -- this step of exposing the leaves to the air gives the tea its color. Green tea, on the other hand, is lightly steamed rather than fermented, so it retains much more of its polyphenols, which increases its antioxidant properties [source: University of Maryland Medical Center].

Green Tea Diet Pills

So how can an ancient beverage be used in a diet pill? Green tea diet pills use the same leaves that are used to make the drinkable green tea, but they are in a concentrated form. When a diet pill contains green tea extract, supposedly, the "extract" is the polyphenols from the green tea leaves.

In addition to EGCG and its benefits -- including increased metabolism -- green tea also contains caffeine, which is said to be a mild appetite suppressant. Caffeine is also said to speed up thermogenesis, which is the body's process of producing heat that leads to fat burning.

Though these benefits can be obtained through drinking green tea, some people would rather swallow a couple pills rather than gulp down cups and cups of a beverage every day. For those who do prefer the pill form, there are many varieties of green tea diet pills. Some pills contain 100 percent green tea extract -- these are basically just super-concentrated green tea. However, the majority of green tea diet pills also contain other weight-loss supplements, such as chromium or hoodia. When used in combination with these stronger appetite suppressants, these are said to be more effective, though additional research is needed to be certain.

When choosing a green tea diet pill, the important thing to look for is the amount of polyphenols, also called catechins, which the pill contains, since this is the main substance that gives green tea its weight-loss properties. If you're taking a pill that contains 100 milligrams of catechins twice daily, that's equivalent to about two cups of green tea. Is the pill worth it? Some experts suggest looking for a pill that contains 125 to 500 milligrams of polyphenols, though there is no established recommended dose [source: Pizzo].

Read on to find out if the polyphenols and catechins are really worth the mouthful!