What Oils Make Your Hair Grow: Rosemary, Castor, Argan

Similar to the discourse around rosemary oil, tretinoin for hair growth has been especially trendy on TikTok. Recent studies have shown that tretinoin, a prescription form of vitamin A used to treat skin conditions like acne and uneven tone, may help enhance the effect of minoxidil used to promote hair growth. Tretinoin, being a potent and concentrated form of retinol, works to increase cell turnover. “We already know from using it on our face that retinol increases skin cell renewal,” Onuoha tells R29. “It could help other ingredients penetrate the scalp — that’s why that combination (claim) has been made. But I haven’t seen any studies showing that retinol will do that much to the hair strands.” The downside to using retinoids on and around the scalp is there’s a high risk of irritation, which could actually make hair loss worse. Instead, most trichologists recommend salicylic acid for gentle exfoliation.