I've never heard of it before, but thought I'd give it a bash. It's called Horny Goat Weed Complex and this is what is in it what the ingredients are equivalent too and what the ingredients provide -

Horny Goat weed extract 200 mg
Equiv. Epimedium sagittatum 1000 mg
Providing Icariin 4 mg
Tribulus Fruit extract 20 mg
Equiv. Tribulus Terrestris 100 mg
Providing Saponins 4 mg
Maca extract 20 mg
Equiv. Lepidium meyenii 100 mg
Providing B-ecdysone 0.1 mg
Korean Ginseng Extract 20 mg
Equiv. Panax Ginseng 80 mg
Providing Ginsenosides 1 mg
Ginkgo Biloba Extract 10 mg
Equiv. Ginkgo Biloba 500 mg
Providing Ginkgo Flavonglycosides 2.4 mg
Terpene Lactones 0.6 mg

Maybe someone can enlighten me on what each thing does as I have not heard of all of them. Ginkgo biloba, Korean Ginseng and Tribulus obviously, but not the rest of the ingredients. Anyone know what the rest of the ingredients do?