Glucosamine sulfate is a precursor to many elements of cartilage. It is extracted from chitin (shells of crabs, oysters and shrimp) and is available in tablet or capsule form, often combined with chondroitin sulfate.
Ginseng is a perennial herb. Dietary supplements are derived from American or Asian ginseng; Siberian ginseng does not contain components that are active in the two forms used in supplements.
Ginkgo (Ginkgo biloba) is prepared from the leaves of the ginkgo tree; the active components are believed to be the terpene ginkgolides and flavonoids.
Fish oil can be extracted directly or concentrated and placed in capsule form. Its active components are co-3 fatty acids [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)].
Feverfew is a dense perennial herb. Parthenolide and glycosides are believed to be the components responsible for its purported anti-inflammatory and smooth muscle relaxant effects.
Dehydroepiandrosterone (DHEA) is a steroid produced by the adrenal gland and is a precursor to estrogens and androgens. Its effects on the body are similar to those of testosterone.
Phosphocreatine (creatine) is a substance that accumulates in muscles; it supplies phosphate to ATP and thus quickly restores ATP during anaerobic muscle contraction.
