Magnesium has many functions in the human body: it is an enzyme cofactor, protects against cardiovascular diseases, improves the functioning of the immune system, and is also a building block of teeth and bones. The effects of its deficiency, such as frequently occurring muscle spasms, are well known. Oral magnesium supplementation is common and widespread used in society. Scientists have thoroughly studied this form of supplementation and proved its efficiency. Recently, however, there have been reports that transdermal therapy seems to be more effective (ex. magnesium oils – aqueous solution of magnesium chloride). The presented arguments are good absorption through the skin, supplying the element directly to cells that need it and omitting the gastrointestinal track in the absorption process. Both in scientific literature and on medical web sites there are articles proving the effectiveness of transdermal therapy appear, the authors of some who claim that it is better than traditional oral therapy. The presented paper is a review of literature as well as recently conducted research on transdermal magnesium therapy and its effectiveness.