Disclosed are: a method for producing an anti-sense nucleic acid which has a wide variation in nucleotide sequences and excellent anti-sense properties at a low cost in a simple manner and in a large scale; and a cosmetic composition or pharmaceutical composition comprising the anti-sense nucleic acid. A method is discovered which can produce a low molecular weight nucleic acid having anti-sense properties from a nucleic acid starting material derived from an organism at a high yield by using a probe nucleic acid having at least a part of the nucleotide sequence of a target gene. An anti-sense nucleic acid produced by using a nucleic acid derived from an organism as a starting material; and a method for producing the anti-sense nucleic acid.