Icariin is a flavonol, a type of flavonoid. It is the prenyl acetylation of kaempferide

Kaempferide

Kaempferide is an O-methylated flavonol, a type of chemical compound. It can be found in Kaempferia galanga .-Metabolism:...

 3,7-O-diglucoside

Glucose

Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...

. The compound is derived from several species of plants in the Epimedium

Epimedium

Epimedium, also known as Rowdy Lamb Herb, Barrenwort, Bishop's Hat, Fairy Wings, Horny Goat Weed, or Yin Yang Huo , is a genus of about 60 or more species of herbaceous flowering plants in the family Berberidaceae...

family, which are commonly known as Horny Goat Weed or Yin Yang Huo. Extracts from these plants are reputed to produce aphrodisiac

Aphrodisiac

An aphrodisiac is a substance that increases sexual desire. The name comes from Aphrodite, the Greek goddess of sexuality and love. Throughout history, many foods, drinks, and behaviors have had a reputation for making sex more attainable and/or pleasurable...

 effects, and are commonly used in Chinese herbal medicine to enhance erectile function, as well as for several other indications.

It is thought that icariin is likely to be the primary active component of Epimedium extracts, as it has been shown to share several mechanisms of action with compounds used in Western medicine to treat impotence and improve sexual function. In particular, icariin has been demonstrated to act as a PDE5 inhibitor

PDE5 inhibitor

A phosphodiesterase type 5 inhibitor, often shortened to PDE5 inhibitor, is a drug used to block the degradative action of phosphodiesterase type 5 on cyclic GMP in the smooth muscle cells lining the blood vessels supplying the corpus cavernosum of the penis...

 and to enhance the production of bioactive nitric oxide

Nitric oxide

Nitric oxide, also known as nitrogen monoxide, is a diatomic molecule with chemical formula NO. It is a free radical and is an important intermediate in the chemical industry...

, as well as mimicking the effects of testosterone

Testosterone

Testosterone is a steroid hormone from the androgen group and is found in mammals, reptiles, birds, and other vertebrates. In mammals, testosterone is primarily secreted in the testes of males and the ovaries of females, although small amounts are also secreted by the adrenal glands...

. It also shows antioxidant

Antioxidant

An antioxidant is a molecule capable of inhibiting the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons or hydrogen from a substance to an oxidizing agent. Oxidation reactions can produce free radicals. In turn, these radicals can start chain reactions. When...

, antidepressant

Antidepressant

An antidepressant is a psychiatric medication used to alleviate mood disorders, such as major depression and dysthymia and anxiety disorders such as social anxiety disorder. According to Gelder, Mayou &*Geddes people with a depressive illness will experience a therapeutic effect to their mood;...

 and nootropic

Nootropic

Nootropics , also referred to as smart drugs, brain steroids, memory enhancers, cognitive enhancers, and intelligence enhancers, are drugs, supplements, nutraceuticals, and functional foods that improve mental functions such as cognition, memory, intelligence, motivation, attention, and concentration...

 effects in animal studies, as well as stimulating osteoblast

Osteoblast

Osteoblasts are mononucleate cells that are responsible for bone formation; in essence, osteoblasts are specialized fibroblasts that in addition to fibroblastic products, express bone sialoprotein and osteocalcin.Osteoblasts produce a matrix of osteoid, which is composed mainly of Type I collagen...

 activity in bone tissue which has been linked to a possible therapeutic role in the treatment of osteoporosis

Osteoporosis

Osteoporosis is a disease of bones that leads to an increased risk of fracture. In osteoporosis the bone mineral density is reduced, bone microarchitecture is deteriorating, and the amount and variety of proteins in bone is altered...

.