PURPOSE:To obtain a composition for hair capable of promoting melanin formation, preventing and improving gray hair by external use to scalp, containing, a nucleic acid-related substance such as adenosine 3',5'-cyclic-phosphate compound, etc., and flavin adenine dinucleotide, etc. CONSTITUTION:A composition for hair containing 0.01-2% nucleic acid-related substance selected from a compound having a basis skeleton shown by formula I, flavin adenine dinucleotide and a salt thereof. The composition is applied to scalp, activates melanoctye, promotes melanin formation, can prevent and improve gray hair. A compound shown by formula II (R1-R3 are H, 1-22C acyl or alkyl; X1 and X2 are H, halogen, thio-containing group, amino or OH; M1 is H or salt-forming cation) is preferable as the compound shown by formula I and adenosine 3',5'-cyclic-phosphate wherein R1-R3, X1 and X2 are all H may be cited.
COMPOSITION FOR HAIR