A composition for use in treating rosacea, the composition comprising a first component comprising a substituted or unsubstituted diindolylmethane (DIM) compound； and (b) optionally a second component comprising a substituted or unsubstituted retinoid compound. Preferably the diindolylmethane compound is 3,3-diindolylmethane or 2,2-diindolylmethane. The retinoid compound is preferably vitamin A palmitate. Preferably the rosacea is selected from pustular rosacea, papulopustular rosacea, erythemato-telangiectatic rosacea, granulomatosus rosacea, rosacea conglobata, rosacea fulminans and phymatous rosacea. A formulation comprising 75mg DIM, 200µg vitamin A palmitate, 175mg tri-calcium phosphate, 20mg microcrystalline cellulose, 11.5mg vitamin C, 10mg fumed silicon dioxide and 6mg magnesium stearate for use in treating rosacea is exemplified. A substituted or unsubtituted diindolylmethane compound (DIM) for use in treating rosacea is also provided.
