Planetary Herbals - Horny Goat Weed Full Spectrum Double Potency 1200 mg. - 60 Tablets Planetary Herbals Horny Goat Weed Full Spectrum is a Chinese tonic for sexual vitality. Epimedium (Horny Goat Weed) is one of the most valued tonics of Chinese herbalism. In China, it is especially used for supporting healthy sexual activity - thus, its name, Horny Goat Weed. Planetary Herbals Full Spectrum Horny Goat Weed combines epimedium extract (standardized to 10% flavonoids as icariin) with whole leaf epimedium to ensure a full spectrum of important constituents.