An organogelling agent for forming reverse worm-like micelles having high safety to living bodies and the environment, favorable feel of use, and a high gelating ability and a thickened gel composition comprising the organogelling agent are provided. Lecithin and ascorbic acid or an ascorbic acid derivative act as an organogelling agent to form reverse worm-like micelles of a variety of oils. A thickened gel composition having a reverse worm-like micelle structure can be prepared with a ternary system of lecithin, ascorbic acid or an ascorbic acid derivative, and a variety of oils.
