Bakuchiol, an active ingredient for hair care?

The bakuchiol is a plant-derived ingredient extracted from the seeds of Psoralea corylifolia, known as babchi and bakuchi. Native to India, this plant holds a key role in Ayurvedic medicine and traditional Chinese pharmacopeia. In skincare, the bakuchiol has emerged in recent years as a natural alternative to retinol, sharing similar properties with retinol. However, bakuchiol differs from retinol by offering better skin tolerance: it is less irritating, causes less flaking and redness, and suits sensitive skin.

To date, no scientific study has examined bakuchiol’s effects on hair.

However, some skin benefits of bakuchiol might also apply to the scalp. Bakuchiol may benefit scalps that tend to become oily due to high sebum production by sebaceous glands linked to genetic predispositions or hormonal imbalance. Sebum protects hair fibers from dehydration and environmental factors, but in excess it gives hair a greasy appearance and can promote dandruff. Bakuchiol may regulate sebaceous gland activity and help prevent hyperseborrhea.

Studies in vitro have shown that bakuchiol can inhibit 5α-reductase, the enzyme that converts testosterone into dihydrotestosterone (DHT). By binding a specific cytosolic receptor, DHT increases sebum production by sebaceous glands. A study on HaCaT human keratinocytes found that bakuchiol at ten µg/mL reduces 5α-reductase expression by 40%, an effect comparable to retinoic acid. If this property is confirmed in vivo, bakuchiol could become a relevant agent for oil-prone scalps.