Beta-sitosterol is a substance found in plants. Chemists call it a “plant sterol ester.” It is found in fruits, vegetables, nuts, and seeds.
Beta-sitosterol is part of a group of plant extracts called phytoesterols. It is believed to be a natural 5-alpha-reductase inhibitor. This is an enzyme that converts testosterone into DHT (dihydrotestosterone). It is believed that beta sitosterol helps battle hair loss by blocking or slowing down the production of DHT.
Beta-sitosterol is particularly important when used in combination with Nettle Root Extract
Beta-sitosterol is also used for heart disease and high cholesterol. It is also used for boosting the immune system and for preventing colon cancer, as well as for gallstones, the common cold, the flu (influenza), swine flu, HIV/AIDS, rheumatoid arthritis, tuberculosis, psoriasis, allergies, cervical cancer, fibromyalgia, systemic lupus erythematosus (SLE), asthma, hair loss, bronchitis, migraine headache, and chronic fatigue syndrome.
Research: https://hairgenx.co.za/scientific-research-for-thinning-hair/ para 7.