We give a simple universal property of the multiplicative structure on the Thom spectrum of an n‐fold loop map, obtained as a special case of a characterization of the algebra structure on the colimit of a lax scriptO‐monoidal functor. This allows us to relate Thom spectra to En‐algebras of a given characteristic in the sense of Szymik. As applications, we recover the Hopkins–Mahowald theorem realizing Hdouble-struckFp and HZ as Thom spectra, and compute the topological Hochschild homology and the cotangent complex of various Thom spectra.