Bakuchiol: a natural alternative to retinol?

The retinol is a vitamin A derivative widely used in dermatology and cosmetics since the 1970s, particularly for its effects on signs of aging and imperfections. It acts by regulating keratinocyte differentiation, stimulating collagen production, and accelerating cellular turnover. The bakuchiol, on the other hand, is a plant-derived compound isolated from the seeds of Psoralea corylifolia, a plant highly regarded in traditional Indian and Chinese medicine. It is only recently, since the 2010s, that it has begun to attract interest in cosmetics as a natural alternative to retinol, especially for sensitive skin.

If these two active ingredients are so often compared, it’s because their chemical structures are similar and because they share several properties. Indeed, the retinol and the bakuchiol have both been shown to reduce the appearance of wrinkles, improve skin texture, reduce hyperpigmentation, and diminish imperfections. They also exhibit certain common mechanisms of action, such as the ability to stimulate fibroblast activity, and thereby the synthesis of collagen and elastin, or to reduce the expression of matrix metalloproteinases, which degrade the structural proteins of the dermal extracellular matrix.

As the cosmetic and dermatological benefits of retinol are well established and its mechanism of action is no longer in doubt, several studies have compared its efficacy to that of bakuchiol to determine whether the latter can legitimately be described as "retinol-like." Here are their conclusions.

Bakuchiol and retinol: comparable efficacy on skin imperfections?

The appearance of pimples results from a combination of mechanisms: excess sebum and a buildup of dead cells causing follicular blockage, proliferation of the bacterium Cutibacterium acnes and local inflammation. Retinoids, such as retinol, are particularly useful for addressing blemishes because they act at multiple levels. By promoting keratinocyte differentiation and stimulating epidermal renewal, they help unclog pores and limit comedone formation. Moreover, certain studies in vitro suggest a sebum-regulating effect of retinol. As for its antibacterial action against C. acnes, this has not yet been demonstrated for retinol, unlike other retinoids such as adapalene. Finally, retinol has anti-inflammatory properties and works by inhibiting the expression of certain cytokines, such as TNF-α and IL-6, helping to reduce inflammatory lesions.

Bakuchiol possesses comparable properties. Studies in vitro have revealed its ability to inhibit the growth of C. acnes, allowing the prevention of inflammation in acne lesions. In parallel, bakuchiol reduces the expression of inflammatory markers such as NF-κB and COX-2, thereby reducing redness associated with certain lesions. Finally, studies conducted in vitro suggest that it may act on lipogenesis and reduce sebum production. One study even compared the sebum-regulating effect of bakuchiol with that of retinoic acid, a prescription-only retinoid, by observing their ability to inhibit 5α-reductase, whose activity correlates with sebum production. The results suggest comparable efficacy.

Several clinical studies have demonstrated the efficacy of bakuchiol and retinol in managing skin imperfections, but none have directly compared them yet, which limits the conclusions. One of these studies evaluated the effectiveness of a 1% bakuchiol formulation versus a salicylic acid–based product in sixty individuals with mild to moderate acne. These participants applied one of the treatments twice daily for six weeks, and their acne severity was assessed using theGlobal Acne Grading System. Another study, conducted in 2009 by NATAKANKITKUL and colleagues, investigated a formulation containing 0.2% retinol compared to a cream with a vitamin C derivative. In that trial, 45 participants with acne applied one of the products daily for eight weeks. The results of both studies, presented below, shed light on retinol and bakuchiol, but a direct comparison is difficult because the effects of these actives on imperfections were not evaluated under the same protocol.

Bakuchiol: as effective as retinol against wrinkles?

If retinol is so popular in cosmetics, it is primarily because of its action on the signs of aging. It works in several ways to target wrinkles, notably by stimulating keratinocyte proliferation and collagen and elastin production by fibroblasts. It also accelerates cell turnover and decreases corneocyte cohesion in the stratum corneum, refining skin texture and reducing the appearance of fine lines. Bakuchiol has similar properties. Several studies in vitro have shown that it can stimulate the expression of genes involved in the type I and III collagen synthesis, while inhibiting metalloproteinases responsible for degrading dermal fibers. Moreover, it increases the production of fibronectin, a glycoprotein essential for extracellular matrix cohesion.

A clinical study conducted with 44 volunteers sought to compare the efficacy of retinol and bakuchiol on signs of skin aging. Over twelve weeks, participants applied a cream containing 0.5% retinol or 0.5% bakuchiol. At the end of the study, both groups exhibited a significant reduction in wrinkle depth, which was slightly more pronounced in the retinol group. However, reported adverse effects were more frequent in that group: 20% of participants experienced skin peeling, compared with only 10% in the bakuchiol group.

Is bakuchiol as effective as retinol in reducing brown spots?

Bakuchiol and retinol both display interesting properties for diminishing pigmented spots. Bakuchiol acts at multiple levels of the melanogenesis process: it inhibits tyrosinase activity—the enzyme that catalyzes the conversion of tyrosine into melanin—and reduces expression of the TRP-1 and TRP-2 proteins, which are involved in the maturation and stabilization of melanin within melanosomes. Retinol, for its part, exerts an effect on hyperpigmentation via direct and indirect mechanisms. It can inhibit the expression of tyrosinase and of TRP-1 and TRP-2 proteins, thereby slowing melanin production, and it can also influence pigment distribution in the epidermis by promoting a more homogeneous dispersion of melanin granules in keratinocytes.

The aforementioned clinical study, conducted on 44 participants who applied a cream containing 0.5% retinol or 0.5% bakuchiol daily for 12 weeks, also assessed the impact of these formulations on pigmentation. The results demonstrated a significant improvement in skin tone uniformity in both groups, with a slightly greater effect in the retinol group.

Bakuchiol is indeed establishing itself as a plant-derived alternative to retinol and appears capable of addressing the same concerns.

The bakuchiol is overall a milder active ingredient than retinol.

Retinol, despite its well-established efficacy, is frequently associated with adverse effects, such as redness, tingling sensations, increased dryness, and visible skin flaking. These effects are directly linked to its mechanism of action: by binding to nuclear RAR (Retinoic Acid Receptors) and RXR (Retinoid X Receptors), retinol triggers an intracellular signaling cascade that modulates keratinocyte proliferation, cell differentiation, and collagen synthesis. However, this intense stimulation of epidermal turnover can temporarily disrupt the skin barrier and increase transepidermal water loss. This phenomenon is especially observed in sensitive skin, although it can affect all skin types.

In comparison, bakuchiol is generally better tolerated. Although the risk of irritation can never be completely excluded, as with any cosmetic active ingredient, studies report a lower incidence of side effects. The bakuchiol can even be used by individuals prone to rosacea, who often have very sensitive skin. The clinical study mentioned earlier, comparing the efficacy of a 0.5% bakuchiol cream with that of a 0.5% retinol formulation, also examined the tolerance of both treatments and specifically assessed the occurrence of peeling and tingling sensations. The charts below, extracted from the study, confirm the superior skin tolerance of bakuchiol compared to retinol.

• NATAKANKITKUL S. & al. Comparison of clinical efficacies of sodium ascorbyl phosphate, retinol and their combination in acne treatment. International Journal of Cosmetic Science (2009).

• MARCHIO F. & al. Bakuchiol in the management of acne-affected skin. Cosmetics & Toiletries (2011).

• CHAUDHURI R. K. & al. Bakuchiol: a retinol-like functional compound revealed by gene expression profiling and clinically proven to have anti-aging effects. International Journal of Cosmetic Science (2014).

• SIVAMANI R. K. & al. Prospective, randomized, double‐blind assessment of topical bakuchiol and retinol for facial photoageing. British Journal of Dermatology (2019).

• KIM S. Y. & al. UP256 inhibits hyperpigmentation by tyrosinase expression/dendrite formation via rho-dependent signaling and by primary cilium formation in melanocytes. International Journal of Molecular Science (2020).

• SODHA P. & al. The use of bakuchiol in dermatology: a review of in vitro and in vivo evidence. Journal of Drugs in Dermatology (2022).