The invention relates to a synergistic composition comprising a dry extract of plant of genus Galeopsis and a compound promoting autophagy selected from biotin and R-N1-spermidine or a salt thereof, wherein R is hydrogen or methyl and mixtures thereof. The synergistic compositions according to the invention may be in the form of a topical formulation or oral formulation and is useful as a promoter of autophagy especially in cells of human scalp hair follicles and in promoting hair growth and/or in the treatment of hair thinning or hair loss.