L-Theanine
An amino acid found in tea with relaxant and neuroprotective effects. L-theanine is used in various fat loss supplements, primarily for its effects on mood/cognition (both alone, and synergistically with caffeine), although there is some (very) preliminary evidence that it also may have anti-obesity effects.
For more information, see the Sloan-Kettering Cancer Center article, “L-Theanine.”
Octopamine
A biogenic amine and constituent of Citrus aurantium (bitter orange). Octopamine is promoted as a fat loss agent, although there is only limited animal (and NO human) data to support this. Any effects on fat loss are likely to be weak, as its oral bioavailability is low.
See David Tolson’s article, “Octopamine Science” for more information.
Sesamin
A lignan in sesame seed with a number of interesting physiological effects. Sesamin can enhance plasma Vitamin E status and reduce experimentally-induced inflammation. It can also be converted to the mammalian lignan enterolactone, which is associated with reduced risk of developing certain cancers and heart disease. Sesamin has been touted as a fat loss supplement, on the strength of animal experiments showing it can increase fatty acid oxidation (especially in conjunction with fish oil). There have been no fat loss studies conducted in humans, however, so the benefits are still largely speculative.
Resveratrol
A polyphenolic antioxidant compound found in red grapes/red wine, peanuts and certain berries – as well as a few other plants (Polygonum cuspidatum – Japanese knotweed – is the primary source used for resveratrol supplements). Studies on resveratrol have linked it to a wide range of benefits: anti-aging, anti-inflammatory, anti-cancer and improvement of cardiovascular health.
Beyond its uses for general health and (possible) longevity, resveratrol is used in many bodybuilding supplements, as it’s an aromatase inhibitor and has been shown to increase sperm production and testosterone levels in rats.
It should be noted, however, that most of the research on resveratrol itself is based on cell cultures and animals. Most human research has used food sources containing mixed polyphenols, thus, it is not known what human health benefits are associated with resveratrol supplements, nor what an effective dose might be.
A related issue with resveratrol supplements is bioavailability: although resveratrol is readily absorbed, it is rapidly metabolized and excreted.
