Astragalus is a large genus of about 2,000 species of herbs and small shrubs, belonging to the legume family Fabaceae, subfamily Faboideae. The genus is native to temperate regions of the Northern Hemisphere. Common names include milk-vetch (most species), locoweed (in western US, some species) and goat's-thorn (A. gummifer, A. tragacanthus). Some pale-flowered vetches are similar in appearance, but vetches are more vine-like.
Astragalus membranaceus is now being purified by supplement companies for the particular natural telomerase activating extracts. Despite lack of evidence and testing, these extracts have started to be marketed as telomere enhancing, and life prolonging extracts. As of January 2009 only three companies offer telomerase activator supplement products from Astragalus: TA Sciences, Terraternal, and RevGenetics provide Astragaloside IV or another extract derived from Astragalus for this purpose. However no independent tests have confirmed that these supplements actually activate telomerase in a human.