FIELD : medicine.SUBSTANCE : group of inventions relates to the field of medicine, specifically to a patch for treating and/or preventing scarring, having a layered structure comprising at least a substrate, a matrix layer comprising an onion extract (A) and an acrylate-vinyl acetate polymer (B), and a release liner, wherein the matrix layer is disposed between the substrate and the release liner such that the matrix layer is in contact with the substrate and the release liner on opposite sides thereof, where the release liner is configured to be detached from the matrix layer, and where acrylate-vinyl acetate polymer (B) comprises elementary units derived from the monomeric components of alkyl acrylate (B1) and vinyl acetate (B2), wherein the alkyl acrylate has the formula CH2=CH-COOR, in which R represents an alkyl group containing from 1 to 20 carbon atoms (B1), and to a method for producing a patch for treating and/or preventing scars.EFFECT : invention provides a high rate of release of the active substance, as well as a high degree of compatibility with the skin, coupled with good adhesion.13 cl, 9 dwg, 6 ex