One must differentiate between three types of products. On the one hand we have the very low priced products which nourish the lashes but do not contain any growth stimulating substances. On the other hand there are medium priced products, like our BeautyLash Eyelash Growth Serum, which contains ingredients that stimulate the production of keratin in the hair follicle and lead to longer and thicker hair. And then there are those products, which actively prolong the growth cycle of the hair. Many of these serums contain a synthetic prostaglandin which show growth effects, but have been, not without reason, viewed critically. These products are in the premium price range, like the BeautyLash Eyelash Growth Booster. The BeautyLash Eyelash Growth Booster however contains a key natural substance derived from the Caribbean coral Plexaura Homomalla which has the same growth effect.