Is the topical application of Nigella sativa (black seed) oil on the skin dangerous?

The nigella oil is obtained by cold pressing of black cumin seeds (Nigella sativa), a herbaceous plant native to Southwest Asia and widely cultivated around the Mediterranean basin and in the Middle East. Used since antiquity, nigella holds a special place in various medicinal traditions, where it was employed to care for the skin and soothe certain sensations of discomfort. This oil appears as an amber to dark brown liquid with a characteristic spicy, slightly peppery aroma of the seed.

In cosmetics, the black cumin seed oil is prized for its richness in fatty acids, mainly unsaturated fatty acids, which endow it with nourishing and emollient properties. These lipids contribute to the strengthening of the hydrolipidic film and contribute to limiting skin dehydration, which can be particularly useful for preventing dehydration lines. Black cumin seed oil also contains bioactive compounds, including thymoquinone, responsible for its antioxidant and anti-inflammatory properties. These effects explain why it is sometimes used to reduce redness and help the skin better cope with oxidative stress.

Even though black seed oil is considered a well-tolerated natural ingredient, the scientific literature reports rare but potentially serious adverse effects following topical application.

Several teams have thus described contact dermatitis acute linked to Nigella sativa oil. An initial case series describes six elderly female patients who developed severe cutaneous eruptions within one to two days after topical application of Nigella sativa oil. The lesions extended well beyond the initial application site, consisting of red-to-violaceous plaques with epidermal detachment and pustules that clinically resembled toxic epidermal necrolysis. In several patients, detached skin exceeded 15% of the body surface area, and some cases were accompanied by fever, necessitating prolonged hospitalization. Histological examination revealed a lichenoid reaction with keratinocyte apoptosis. Patch tests with the oil were positive, and chemical analysis suggested an allergic reaction to thymoquinone.

These findings are supported by a second case series involving three female patients, also hospitalized for severe acute contact dermatitis after applying black cumin oil. Again, the reactions were striking, with lesions extending beyond the application site, widespread skin detachment, sometimes accompanied by fever, and clinical features suggestive of Stevens–Johnson syndrome, a form of toxic epidermal necrolysis. Skin biopsies revealed diffuse epidermal apoptosis, and patch testing with the patients’ black cumin oil yielded positive results.

Less frequently, severe systemic reactions have been described after topical application of nigella oil. A single case report describes the onset of DRESS syndrome, a severe, delayed immunoallergic reaction. The patient presented with extensive erythema, marked eosinophilia (an increase in the immune cells involved in allergic responses), lymphadenopathy (enlarged lymph nodes), and atypical lymphocytes, without internal organ involvement. The diagnosis was confirmed by a positive patch test to nigella oil. The patient was treated with systemic corticosteroid therapy, and the symptoms resolved. Although this case is exceptional, it underscores that nigella oil can be involved in severe, delayed cutaneous reactions mediated by T lymphocytes.

Overall, these observations highlight that, despite its natural image and traditional uses, Nigella sativa oil is not without allergenic potential, particularly when applied undiluted.

Note : The adverse effects described here apply exclusively to the topical application of blackseed oil. Oral ingestion requires additional precautions, particularly due to its potential anticoagulant effects.

When applied topically, it is important to know that black seed oil must always be diluted.

For this purpose, you can use another vegetable oil, such as jojoba oil, sweet almond oil or argan oil for example. A dilution of 5 to 10%, depending on your skin’s sensitivity, is generally recommended.

Let’s also note that, while black seed oil can be applied to the skin, scalp, or hair, it is not suitable for mucous membranes or the eye area. Thus, if you use black seed oil on your face, it is important to avoid any contact with your eyes. Finally, before incorporating black seed oil into your skin care routine, it is advisable to conduct a patch test, to ensure that your skin does not react to this ingredient. To do this, apply a small amount of black seed oil to the inside of your elbow or behind your ear and wait 24 to 48 hours. If you observe no redness, irritation, or itching, you can begin using it gradually.

• HASSAR M. & al. Acute and chronic toxicity of Nigella sativa fixed oil. Phytomedicine (2002).

• ORO S. & al. Dermites de contact à l’huile de nigelle : une nécrolyse épidermique toxique "de contact" ? Annales de Dermatologie et de Vénéréologie (2017).

• HUA C. & al. Association between severe acute contact dermatitis due to Nigella sativa oil and epidermal apoptosis. JAMA Dermatology (2018).

• SCHEERS C. & al. Local and systemic adverse skin reactions following the use of herbal products believed to contain Nigella sativa seeds and oil. Contact Dermatitis (2018).

• KIM B. & al. Black cumin (Nigella sativa L.): A comprehensive review on phytochemistry, health benefits, molecular pharmacology, and safety. Nutrients (2021).

• BEN-SAID B. & al. Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome after topical use of Nigella sativa (black cumin) oil. Contact Dermatitis (2022).