What is it?
Bakuchiol is a chemical compound (phytochemical) that is abundant in the leaves and seeds of the plant Psoralea corylifolia. Bakuchiol is chemically classified as a meroterpene phenol. Although structurally different than retinol, it is considered a functional analogue of retinol.1

Bakuchiol provides antiaging and antiacne effects similar to retinoids and may be more tolerable than retinol. A clinical trial comparing antiaging effects of retinol and bakuchiol found no statistical difference in effectiveness between these two treatments. They were both equally effective at decreasing wrinkle surface area and hyperpigmentation, two concerns from aging and chronic sun exposure. However, the retinol users reported more facial scaling and stinging.2 

Like retinol, topical application of bakuchiol has been shown to effect gene expression of proteins important in aging, namely types I, III, and IV collagen. Studies involving twice daily topical application of bakuchiol showed statistically significant improvement in lines, wrinkles, pigmentation, elasticity, firmness, and overall reduction in photo-damage.

Bakuchiol exhibits antioxidant activity and inhibits the growth of P. acnes, Staphylococcus and Candida, making it an excellent candidate for the treatment of acne. Bakuchiol has been shown to effectively reduce acne especially in combination with salicylic acid.3 

Potential negative side effects:
Although initially reported as non-sensitizing, reports are beginning to crop up offering evidence that people can have an allergic reaction to bakuchiol.4 Bakuchiol appears otherwise to be a safe plant-derived ingredient. However, keep in mind that bakuchiol is a relatively new cosmetic ingredient.
Good for the following conditions: Skin aging and acne. May be helpful if you are sensitive to retinol or retinoid-like ingredients.

Drupanol, Chiba, (+)-Bakuchiol, 4-(3-Ethenyl-3,7-dimethyl-1,6-octadienyl)phenol, Phenol, 4-[(1E,3S)-3-ethenyl-3,7-dimethyl-1,6-octadienyl]-, Phenol, 4-(3-ethenyl-3,7-dimethyl-1,6-octadienyl)-, (S-(E))-, 4-(3,7-Dimethyl-3-vinylocta-1,6-dien-1-yl)phenol, and others. See PubChem for a complete list of names.

1) Chaudhuri RK, Bojanowski K. Bakuchiol: a retinol-like functional compound revealed by gene expression profiling and clinically proven to have anti-aging effects. Int J Cosmet Sci. 2014;36(3):221–230. doi:10.1111/ics.12117.
2) Dhaliwal S, Rybak I, Ellis SR, et al. Prospective, randomized, double-blind assessment of topical bakuchiol and retinol for facial photoageing. Br J Dermatol. 2019;180(2):289–296. doi:10.1111/bjd.16918
3) Chaudhuri, R. K., & Marchio, F. (2011). Bakuchiol in the management of acne-affected skin. Cosmetics and Toiletries, 126(7), 502.
4) Malinauskiene L, Linauskiene K, Černiauskas K, Chomičiene A. Bakuchiol-A new allergen in cosmetics. Contact Dermatitis. 2019;80(6):398–399. doi:10.1111/cod.13211.

How safe is it?

Hang tight. We're thinking.