Background Propionibacterium acnes is a major contributing factor to the inflammatory component of acne. The interaction of P. acnes with keratinocytes leads to an innate immune response via activation of toll-like receptors (TLR2, TLR4) resulting in the production and secretion of pro-inflammatory mediators. TSC, an isoprenylcysteine small moleculemodulates inflammatory signaling pathways and kills P. acnes. TSC represents a novel cosmetic functional ingredient that provides relief from blemishes in acne prone skin.