HAIR DYEING AGENT COMPOSITION

PURPOSE: To obtain a hair dyeing agent composition having excellent shampoo fastness and shelf stability, capable of simply restoring damaged hair, containing an iridoid-based compound, an amino acid and an alcohol. CONSTITUTION: This hair dyeing agent composition contains one or more iridoid- based compounds selected from an iridoid compound of formula I (R1 is H, CH3 , COOH, etc.; R2 and R3 are each H or OH; R4 is CH3 or CH2 OH) and a secoiridoid compound of formula II (R5 is CH3 , CHO, etc.; R6 is H or COOA1 ; A1 is an alkyl), an amino acid and an alcohol as active ingredients. The amount of the iridoid-based compound is 1-5wt.%, that of the amino acid is 0.1-10 pts.wt. based on 1 pt.wt. of the iridoid-based compound and that of the alcohol is 10-90wt.%. The hair dyeing agent composition is adjusted to pH6.5 to pH10. The addition of the alcohol and the adjustment of pH6.5 to pH10 improve dyeing properties, curl retention, no damage to hair, damage restoring properties, shampoo fastness and easiness pharmaceutical preparation and the composition is applicable even to animals such as dogs and cats besides human beings.