Humulus lupulus Cannabaceae
Common hop is a perennial herbaceous climbing plant which sends up new shoots in early spring and dies back to the cold-hardy rhizome in autumn. It is native to the temperate Northern Hemisphere.
The flower cones or strobiles of the plant, known as hops, are used in the production of beer to impart bitterness and flavor, and for their preservative qualities. The extract is antimicrobial, which makes it useful for making natural deodorant. Hops also contain the potent phytoestrogen, 8-prenylnaringenin that may have a relative binding affinity to estrogen receptors. The four major essential oils in hops are Myrcene, Humulene, Caryophyllene, and Farnesene which comprise about 60–80% of the essential oils for most hop varieties. Hop also contains linalool, tannins, and resin.
Hops are also used in herbal medicine for their sedative and relaxing effect. Hops is used traditionally as a treatment for anxiety, restlessness, and insomnia. Hops may be used alone, but more frequently they are combined with other herbs. The relaxing effect of hops may be due, in part, to the specific chemical component dimethylvinyl carbinol. Hops tend to be unstable when exposed to light or air and lose their potency after a few months’ storage.
 Antimicrobial screening of essential oils and extracts of some Humulus lupulus L. cultivars.”. Pharm Weekbl Sci. 1992 Dec 11;14(6):353-6.. http://www.ncbi.nlm.nih.gov/pubmed/1475174?dopt=Abstract.
 Hops [CO2] Extract”. Toms of Maine. http://www.tomsofmaine.com/products/ingredient-detail.aspx?id=110&name=Hops%20%5BCO2%5D%20extract.
 Identification of a potent phytoestrogen in hops (Humulus lupulus L.) and beer”. J Clin Endocrinol Metab.. 1999 June. http://www.ncbi.nlm.nih.gov/pubmed/10372741.