An adhesive patch applied to a persons skin much like a bandage, comprising an adhesive underside. Affixed to the adhesive underside is a reservoir in contact with the skin, and containing electrolytes and nutrients to be administered transdermally. The reservoir comprises multiple layers. The layer closest to the skin is microporous, thereby permitting substances to migrate from the reservoir to and from the skin. The microporous layer is followed by a pair of layers. The first layer of the pair consists of a water-soluble material, followed by a layer containing electrolytic and nutrient substances to be released. The water-soluble layer dissolves from contact with perspiration, thereby freeing the electrolytic and nutrient substances, allowing them to migrate through the holes to the skin. More pairs of layers may be situated behind such that small amounts of electrolytes are released to the skin over time in a controlled manner.