Plantur 39 Caffeine Tonic protects the hair roots and strengthens hair growth. Contains caffeine, which actively blocks testosterone from weakening the hair roots. Also contains the vitamin niacin and zinc salts to strengthen hair growth.Furthermore, it contains bio-active ingredients, successfully used for hormone replacement therapy in menopausal women. Ideal if you choose not to wash hair daily with Plantur 39 Caffeine Shampoo. The alcohol in the tonic is not harmful to the scalp.