Coconut oil, a potential solution for seborrheic dermatitis?

Seborrheic dermatitis is a common inflammatory skin condition that mainly affects areas rich in sebaceous glands, such as the scalp, the face—particularly the sides of the nose and the eyebrows—the upper chest, and the area behind the ears. It typically presents with redness, whitish or yellowish flakes (scales), and itching of varying intensity. On the scalp, it is often associated with dandruff. Seborrheic dermatitis is multifactorial: it results in particular from an interaction between sebum production, an inflammatory response of the skin, and the proliferation of yeasts of the genus Malassezia, microorganisms that are naturally present on the skin surface but can become problematic when they grow excessively.

To date, the scientific evidence supporting the use of coconut oil in seborrheic dermatitis remains limited.

Some studies nevertheless suggest promising directions, particularly regarding the balance of the scalp microbiome. One metagenomic study specifically examined the effect of applying coconut oil on the scalp microbiome. The study followed 140 women, including 70 with dandruff, over 16 weeks, with 12 weeks of coconut oil treatment and 4 weeks of follow‑up. The researchers analyzed nearly 900 samples to observe changes in the bacterial and fungal composition of the scalp. The results showed that regular use of coconut oil altered the microbial ecosystem: it was notably associated with an increase in certain commensal scalp bacteria, such as Cutibacterium acnes, and with a modulation of the presence of yeasts of the genus Malassezia.

These results are interesting because seborrheic dermatitis is closely linked to an imbalance of the skin microbiome, particularly to an overgrowth of Malasseziayeasts.

The ability of coconut oil to modulate this ecosystem could therefore, in theory, help improve the scalp environment. However, these findings should be interpreted with caution. The study mainly shows changes in the microbiome, without clearly demonstrating an improvement in inflammatory symptoms. It is therefore difficult to state that coconut oil is an effective treatment for seborrheic dermatitis. Moreover, because of its rich, occlusive texture, coconut oil applied in its pure form can sometimes accentuate the greasy appearance of the scalp or of areas already rich in sebum, which can be counterproductive in cases of seborrheic dermatitis.

If you suffer from seborrheic dermatitis, you can turn to antifungal shampoos containing ketoconazole, ciclopirox olamine or piroctone olamine. If symptoms persist, do not hesitate to seek advice from a healthcare professional.

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