Letheen Broth modified is a highly nutrious liquid medium recommended for use in microbiological testing of cosmetics.

Beef extract and Casein peptone provide nitrogen, vitamins, minerals and amino acids essential for growth. Yeast extract is the source of vitamins, particularly of the B-group. Sodium chloride supplies essential electrolytesfor transport and osmotic balance.Glucose is a fermentable carbohydrate providingcarbon and energy. Lecithin, Polysorbate 80 and sodium bisulfite neutralize quaternary ammonium compounds and partially neutralize the preservative system commonly found in cosmetics.