Horsetail (Equisetum Arvense) – Packed with silica, this herb encourages connective tissue to grow, strengthen and remain elastic, which in turn can give you firmer and tighter skin. As a powerful astringent and anti-inflammatory agent horsetail can treat wounds and burns while reducing the effects of eczema and acne. The horsetail plant is the only surviving member of the class Equisetopsida, making it a living fossil.