Nigella sativa oil: a natural solution against keratosis pilaris?

The keratosis pilaris is a common, benign skin condition characterized by the appearance of small, rough papules, most often on the arms, thighs, and buttocks. It results from a keratinization disorder, in which keratin accumulates at the opening of hair follicles, forming horny plugs. This hyperkeratinization is often associated with dry, sometimes inflamed skin, and can be promoted by genetic or hormonal factors or certain environmental conditions. Although harmless, the keratosis pilaris can be perceived as unsightly, driving the search for solutions to reduce its appearance.

Keratosis pilaris is typically managed with keratolytic agents, such as glycolic acid or lactic acid, which are able to remove excess keratin.

However, to date, the nigella oil is not associated with keratolytic properties. Its lipid profile and bioactive compounds, such as thymoquinone, instead grant it nourishing, antioxidant, and anti-inflammatory properties that may improve skin comfort and support the skin barrier. However, no clinical trial has demonstrated a specific effect of nigella oil on keratosis pilaris or on normalizing follicular keratinization. Thus, it does not target the central mechanism of this skin concern, namely keratin accumulation.

That said, a clinical trial recently highlighted the potential of a nigella extract in another form of keratosis: arsenical keratosis. Although distinct from keratosis pilaris, it shares certain biological mechanisms, notably hyperkeratinization. In this study involving 32 patients with moderate to severe palmar arsenical keratosis, an ointment based on seed extract of Nigella sativa was applied for 12 weeks (concentration not specified). The results showed a mean lesion size reduction of 72.8%. The study authors suggest that the nigella extract may exert dose-dependent cytotoxicity on hyperproliferative keratinocytes, which could explain the observed improvement, although this mechanism has not been demonstrated.

These results are interesting, but they do not permit firm conclusions regarding the efficacy of nigella oil on keratosis pilaris.

Indeed, the study investigated arsenical keratosis which, although similar to keratosis pilaris, is not strictly identical. In addition, it was not nigella oil that was tested but a nigella seed extract formulated in an ointment, and currently only one small clinical trial is available. Therefore, it is not possible to extrapolate these data to the use of the nigella oil for keratosis pilaris. In practice, for individuals seeking to reduce the appearance of their keratosis pilaris, it remains preferable to turn to active ingredients whose efficacy is better documented, particularly keratolytic agents.

Finally, it should be noted that keratosis pilaris is a benign, non-threatening condition that does not require treatment, and its management is a matter of personal aesthetic choice.

• SCHWARTZ R. A. & al. Keratosis pilaris: A common follicular hyperkeratosis. Pediatric Dermatology (2008).

• GABBIANELLI R. & al. Antioxidant and anti-inflammatory properties of Nigella sativa oil in human pre-adipocytes. Antioxidants (2019).

• MOHAMADI N. & al. The therapeutic effects of Nigella sativa on skin disease: A systematic review and meta-analysis of randomized controlled trials. Evidence-Based Complementary and Alternative Medicine (2022).

• MURRELL D. F. & al. A review of the scoring and assessment of keratosis pilaris. Skin Appendage Disorders (2023).

• NARGIS F. & al. Effect of chloroform extract of Nigella sativa seed in the treatment of palmar arsenical keratosis. Saudi Journal of Medical and Pharmaceutical Sciences (2025).