Contrary to what you might think, horsetail does not in fact come from a horse's tail – need I remind you of Jessica Simpson's Buffalo wings gaff? Horsetail is actually a plant that is fernlike in quality that's been used since ancient Greek and Roman times for medicinal purposes, such as healing cuts and treating tuberculosis.
As far as beauty is concerned, horsetail extract helps to stimulate collagen and elastin production, as well as protect the skin from oxidation. Hence you'll often find this ingredient in anti-ageing products like Burt's Bees Radiance Night Crème ($39.95) and Ilcsi Organic Skincare Anti-ageing Lifting Moisturiser ($90). Also try Pevonia Botanica Mattifying Oily Skin Mask ($66.95).
Stockists: Burt's Bees, Ilcsi Organic Skincare (1800 808 993), Pevonia Botanica (1800 069 116).