The Black Willow (Salix nigra) tree, found in the eastern part of the North American continent, is famous for its dark brown, ridged bark. The fresh bark is rich in tannins and salicylic acid-like materials. The freshly prepared extract has been reported to have analgesic, antiseptic, astringent, anti-pyretic and anti-inflammatory properties.
Black willowbark has been shown to possess potent antimicrobial properties. Efficacy testing has shown that the extract has activity against Staphylococcus aureus andPropionibacterium acnes, two of the skin flora implicated in the formation of acne. When added to cosmetic formulations, the extract/tincture can also increase the cell renewal capabilities of cosmetic formulations.
Black willowbark is a safe way to get the benefits of a B-hydroxy acid without the risk of irritation. When compared to salicylic acid the extract/tincture is better able to increase turnover of the stratum corneum and also has more in vitro antimicrobial activity against Staphylococcus aureus and Propionibacterium acnes. Coupled with this increased efficacy, it has less irritation potential than salicylic acid. The effects of black willow bark are mostly attributed to the salicin naturally occurring in the plant. Salicin is the precursor of salicylic acid, which prevents or counteracts inflammation and is an analgesic. Studies have found that it also an anti-oxidant. The salicin component has anti-inflammatory effects. The tannin content of black willow bark has an astringent property. | 
