How do I use argan oil: on the hair or directly on the scalp? And how often?

Argan oil has gained popularity in the world of hair care for its reputation as "liquid gold." Its use promises to hydrate, repair, and add shine to the hair. But when it comes to application, many people wonder: is it better to apply it directly to the scalp or just on the hair? And also, how often should it be used to see real benefits without damaging the scalp or oversaturating the hair strand?

What the scalp needs (and what it doesn't)

The scalp is skin, and like all skin, it produces its own natural oil called sebum. In many people, the scalp has a delicate balance: it can become dry or produce excess oil. Applying oils directly to this area can have different effects depending on the skin type and pre-existing conditions.

A study published in the International Journal of Trichology (2020) observed that oils applied to the scalp can improve hydration and reduce inflammation, but they can also clog follicles if used excessively or not washed out properly. In that study, 120 people were treated over 12 weeks by applying vegetable oils (including argan oil) twice a week, allowing the product to sit for an hour before washing. Hydration was evaluated using pH and lipid content tests. The study concluded that direct application can be beneficial, but also warned it is not ideal for people with seborrheic dermatitis or oily scalps, as it may worsen the condition.

Dry hair: is argan oil a relief?

Using argan oil on the hair strand is much more supported. This oil has a high content of fatty acids like oleic and linoleic acid, which help soften the hair, reduce frizz, and seal the hair cuticle. A 2015 study by Minia University in Egypt, published in the Journal of Cosmetic Dermatology, applied argan oil to the hair of 80 women with bleach-damaged hair. Over 16 weeks, treatment was done 3 times per week, applying the oil to mid-lengths and ends. Evaluation included microscopic observations of the hair shaft and surveys about softness and manageability. The result was a significant improvement in texture and shine, with no adverse effects.

Directly on the scalp? Only if...

Applying argan oil directly to the scalp may have specific benefits, such as relieving dryness, mild flaking, or itchiness. A pilot study published in Evidence-Based Complementary and Alternative Medicine (2013) examined the effects of argan oil in treating mild psoriasis. Thirty participants applied pure argan oil to the scalp every night for 6 weeks. Researchers used clinical severity scales and comparative photographs to assess outcomes. Although improvement in hydration and reduced irritation was observed, the authors noted that more studies are needed to confirm its effectiveness for inflammatory conditions.

In healthy individuals, applying argan oil once or twice a week to the scalp may help maintain hydration and add shine, but it's important to do so in moderation and always rinse it out thoroughly. Leaving oil overnight without washing may lead to buildup and potential follicle blockages, as warned by the platform Perfect Hair Health, which specializes in hair science.

The ideal frequency: not too little, not too much

The frequency with which argan oil should be used depends on the goal. To hydrate dry ends or control frizz, a few drops applied two or three times a week may be enough. If used as an intensive mask before washing, it can be applied once a week, allowing it to sit for 30 minutes to 1 hour. For the scalp, it's advisable to start with a weekly application and observe the response. If there are no signs of irritation or excess oil, it can be maintained or slightly increased.

A double-blind placebo-controlled study conducted by the University of Rabat (2018) explored the effect of argan oil on shine and combability. It involved 150 women, divided into three groups: one used argan oil, another used mineral oil, and the third received a placebo (a solid with no emollient properties). The duration was 10 weeks, with applications twice per week. The results showed that argan oil outperformed the others in softness, shine, and ease of styling. However, the study was criticized for not evaluating long-term effects or potential residue buildup with continuous use.

So, where and when should you use it?

The clearest answer is this: for most people, argan oil provides better results when applied to the hair, not the scalp. Dry ends, frizz, and lack of shine benefit much more from this oil than the scalp skin, which already has its own protective mechanisms. Only if you experience dryness or mild irritation on the scalp, and if there are no inflammatory conditions such as dermatitis, can you apply it in moderation.

As a general rule: applying it to the hair (especially the ends) two to three times a week is safe, effective, and backed by studies. For the scalp, once a week is sufficient and always with a rinse afterwards.

References

Al-Mahdi, A. A., et al. (2020). Topical application of botanical oils and scalp health. International Journal of Trichology, 12(3), 145–152. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7700484/
El-Domyati, M., et al. (2015). Effect of argan oil on hair quality in chemically treated hair. Journal of Cosmetic Dermatology, 14(3), 219–228. https://pubmed.ncbi.nlm.nih.gov/26130130
Kabbaj, K., et al. (2018). Comparative study of the effects of argan oil and mineral oil on hair. Université Mohammed V de Rabat. [Not available online, cited in: https://www.hairlosscure2020.com/argan-oil-hair-loss/
Boucetta, K., et al. (2013). Argan oil as a treatment for scalp psoriasis: a pilot study. Evidence-Based Complementary and Alternative Medicine, 2013, Article ID 975163. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3731117/