TLDR Procyanidin B-2 is safe to use on skin as a hair growth product.
In 1999, researchers conducted toxicological tests on procyanidin B-2, a plant-derived compound, to assess its safety as a topical hair growth agent. The tests included mutagenicity assessments with bacteria and mice, chromosomal tests with CHL cells, acute toxicity via subcutaneous injections in rats, skin and eye irritation tests with rabbits, and skin sensitization tests with guinea pigs. The results indicated that procyanidin B-2 was non-mutagenic, did not cause chromosomal aberrations except for polyploidy, and was not toxic at doses up to 2000 mg/kg. It also did not cause significant skin or eye irritation or skin sensitization. These findings led to the conclusion that procyanidin B-2 is safe for external use as a hair growth agent. The number of animals used in each test was not specified in the summary.
79 citations,
March 1999 in “The journal of investigative dermatology/Journal of investigative dermatology” Procyanidin compounds from grape seeds were found to significantly increase mouse hair growth.
64 citations,
October 1998 in “Acta dermato-venereologica” Grape seed proanthocyanidins can promote hair growth.
6 citations,
October 2017 Indian Gooseberry has potential for cancer prevention and treatment and promotes hair growth.
1 citations,
January 2001 in “Cosmetics and toiletries” Procyanidin B-2 from apple juice significantly increases hair growth and may be more effective than minoxidil without side effects.
27 citations,
September 2017 in “Journal of Medicinal Food” Annurca apple supplement safely increases hair growth and keratin in humans.
42 citations,
March 2006 in “Drug Discovery Today: Therapeutic Strategies” The conclusion is that we need more effective hair loss treatments than the current ones, and these could include new drugs, gene and stem cell therapy, hormones, and scalp cooling, but they all need thorough safety testing.
151 citations,
May 2014 in “American Journal of Clinical Dermatology” Effective treatments for male pattern baldness include oral finasteride and topical minoxidil, while topical minoxidil is best for female pattern baldness.
