Horny-Goat-Weed 

an aphrodisiac and vitalising tonic for men and women

In China it is known as Yin Yang Huo, which means "licentious goat plant." It has been used for over 2,000 years as a traditional remedy for kidney, liver and joint disorders, although it is most commonly used as an aphrodisiac and vitalising tonic for men and women. Seb Cox explains I use this as a general sex tonic. I take about 500 mg everyday before breakfast. I also use it as an aphrodisiac taking about 1500 mg occassionally  before activities begin. It is recommended by herbal specialist for the following :

- Increase the pituitary gland's production of androgens thus increasing testosterone production and release

- Increase libido or sexual drive 

- Stimulates the sensory nerves 

- Promotes erectile function 

- Supports muscular growth and Health 

- Alleviates fatigue 

Be careful where you buy it from. I would probably not buy it from a sex shop.