Nail fungus is a common issue, often slow to eradicate. Like any fungal infection, it requires rigorous treatment. Some natural remedies, such as black cumin seed oil, are sometimes mentioned. Can this vegetable oil really act against nail fungus? Continue reading to learn more.
Nigella sativa oil to treat nail fungus?
Summary
Published on January 28, 2026, updated on January 28, 2026, by Pauline, Chemical Engineer — 5 min of reading
Themes:
≈ 5.5%
Estimated global prevalence of nail fungus.
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Is Nigella sativa oil effective in eliminating nail fungus?
The mycosis of the nail, or onychomycosis, is a fungal infection that most often affects the toenails but can also involve the fingernails. It is caused by dermatophytes, yeasts, or molds, and manifests as a thickening of the nail, discoloration that can range from yellow to brown, and increased brittleness, even progressive detachment of the nail plate. This infection develops slowly and can be difficult to eliminate due to the dense, keratinized structure of the nail, which serves as a natural barrier limiting the penetration of treatments. While onychomycosis is generally benign, it can become persistent, spread to other nails due to its contagious nature, and lead to complications in certain at-risk populations, such as individuals with diabetes or circulatory problems.
If you suspect a nail fungal infection, it is best to seek the advice of a healthcare professional, such as a pharmacist, who can guide you on the appropriate products to eliminate it.
When faced with this type of nail issue, some people prefer to turn to natural solutions, whether for themselves or their children. However, the natural origin of a product does not guarantee its efficacy or tolerability. Regarding the Nigella sativa seed oil and nail fungus, its effectiveness is far from proven. The theoretical interest in nigella often rests on the presence of thymoquinone, a bioactive compound that has demonstrated antibacterial (against Gram-positive and Gram-negative bacteria) and antifungal properties in various experimental models. However, these effects have primarily been observed with isolated thymoquinone or concentrated extracts, or even with the Nigella sativa essential oil, which contains much higher concentrations of thymoquinone. Conversely, the Nigella sativa seed oil contains only a small proportion—typically less than 1%—which makes any significant antifungal activity during topical application on the nail uncertain.
To date, the only study suggesting a potential role for nigella oil in the context of onychomycosis does not concern its intrinsic antifungal activity, but rather its function as an agent facilitating the penetration of a reference antifungal. The study in question aimed to develop an innovative formulation of ketoconazole, a well-known antifungal, in the form of a microemulsion incorporated into a hydrogel containing nigella oil to enhance its penetration. The researchers demonstrated that the ketoconazole–nigella oil formulation provided improved antifungal activity in vitro against Candida albicans and Aspergillus niger compared with a marketed ketoconazole cream.
Comparative ex vivo release of the microemulsion combining ketoconazole and black seed oil compared to the marketed cream.
Source: MOMIN M. & al. Formulation evaluation of ketoconazole microemulsion-loaded hydrogel with nigella oil as a penetration enhancer. Journal of Cosmetic Dermatology (2019).
In this study, Nigella sativa oil was not used as an antifungal agent, but as a component of the vehicle intended to improve the diffusion of the product through keratinized structures. Interestingly, the placebo formulation containing Nigella sativa oil without ketoconazole also showed a moderate antifungal activity, suggesting its own intrinsic, albeit secondary, biological effect.
Antifungal activity of the placebo microemulsion (with nigella oil but without ketoconazole), the microemulsion combining nigella oil and ketoconazole, and the marketed cream against Candida albicans and Aspergillus niger.
Source: MOMIN M. & al. Formulation evaluation of ketoconazole microemulsion-loaded hydrogel with nigella oil as a penetration enhancer. Journal of Cosmetic Dermatology (2019).
However, this study has significant limitations. It does not demonstrate the efficacy of black seed oil alone against nail fungus but rather its potential role as an adjuvant in a complex pharmaceutical formulation. Moreover, the diffusion tests were conducted on porcine skin rather than on actual human nails, which limits the relevance of the results for nail application. Finally, this is a preclinical study with no clinical evaluation in patients with onychomycosis.
In conclusion, it is currently impossible to assert that Nigella sativa oil can treat a nail fungal infection. In cases of onychomycosis, it is preferable to rely on established antifungal treatments recommended by a healthcare professional.
Sources
SPENGLER G. & al. Nigella sativa essential oil and its bioactive compounds as resistance modifiers against Staphylococcus aureus. Phytotherapy Research (2019).
MOMIN M. & al. Formulation evaluation of ketoconazole microemulsion-loaded hydrogel with nigella oil as a penetration enhancer. Journal of Cosmetic Dermatology (2019).
WONG A. & al. Onychomycosis: An updated review. Inflammation & Allergy-Drug Targets (2020).
HAMAAMIN H. H. & al. The antibacterial property of Nigella sativa (black seed) oil against Gram-positive and Gram-negative bacteria. Kurdistan Journal of Applied Research (2021).
