The present invention relates generally to compositions and methods of using the same such as, for example, methods of treating the skin of a subject using a composition as described herein. The composition may comprise a diluent, a solvent, a penetration enhancing agent, a skin brightening agent, a skin renewing agent, a thickening agent, an anti-irritant, a chelating agent, an active pharmaceutical ingredient (API), optionally a pH adjustment agent, and optionally a preservative. The composition may further comprise L-arginine and/or L-citrulline and/or esters and/or derivatives thereof.