Safflower oil and hair: what are the benefits?

The safflower oil is a gentle vegetable oil that has been used for centuries. Initially valued for its dyeing and therapeutic properties, it has over time carved out a prime spot in the field of cosmetic care. Whether pure or incorporated into products, safflower oil is beneficial when applied to hair and helps to make the hair shiny and soft while moisturising the lengths.

These properties of the safflower oil are derived from its richness in unsaturated fatty acids such as oleic acid. Naturally present in the hydrolipidic film that coats the hair, it strengthens this protective veil acting as a barrier to external agents. Moreover, safflower oil contributes to the restoration and cohesion of the cuticle scales, the outer part of the hair fibres. In doing so, it promotes the impermeability and protection of the inner layers like the cortex. Rich in keratin, the latter gives the hair its flexibility and elasticity. Vegetable safflower oil is thus an interesting ingredient for dry or damaged hair.

Safflower oil is also a friend to fine and fragile hair as it possesses antioxidant activity. Indeed, the tocopherols present in this vegetable oil are recognised free radical scavengers. Through an electron donation, they stabilise the free radicals created following oxidative stress (pollution, UV rays, tobacco...). Thus, tocopherols prevent them from damaging the hair bulb and accelerating the formation of split ends. Several studies have indeed shown that oxidative stress is harmful to the scalp and hair and can promote the appearance of white hair, hair loss or even alter the visco-elastic properties of the fibres.

Advice : to take care of your hair length with safflower oil, you can perform a oil bath once or twice a week. To do this, apply a few drops of safflower oil strand by strand, starting from the mid-lengths and going to the ends. After leaving the treatment on for about fifteen minutes, you can proceed with your shampooing.

The safflower oil could also have a stimulating effect on hair growth. Several mechanisms are involved, among which the activation of the Shh/Gli signalling pathway by linoleic acid and β-sitosterol present in its composition. This pathway impacts the hair cycle and promotes the transition between the telogen phase (shedding phase) and the anagen phase (growth phase) of follicular cells.

Furthermore, a study conducted on rats demonstrated that the topical application of a 1% safflower oil solution stimulated twice as much hair growth as a 2% minoxidil solution. For context, minoxidil is a molecule often used to treat alopecia. Although the biological mechanisms that enable rat hair growth are slightly different from those involved in human hair growth, the evidence is encouraging regarding the effectiveness of safflower oil.

Safflower oil can also be used to combat minor tingling or itching of the scalp. This soothing vegetable oil helps to reduce the production of pro-inflammatory cytokines, such as interleukins 6 and 12 (IL-6 and IL-12) and tumour necrosis factor (TNF-α). Cytokines are one of the most common families of chemical mediators of inflammation and are involved in various inflammatory mechanisms (itching, irritation, redness...).

Furthermore, studies in vitro conducted on linoleic acid, which is present in over 70% of safflower vegetable oil, have shown that this molecule inhibits the signalling pathway related to the nuclear factor NF-κB. This protein, which is involved in the immune response, is responsible for the production of interleukins 1 and 2 (IL-1 and IL-2) and is implicated in the regulation of various inflammatory mechanisms. The application of a few drops of safflower oil on the scalp can help to downregulate these processes and soothe it.

Safflower oil is finally attributed with antibacterial and antifungal properties , useful for keeping the populations of microorganisms on the scalp under control. Studies have indeed shown that this botanical extract has a bactericidal and bacteriostatic activity against various Gram-positive bacteria. Safflower oil acts by hydrolysing the 1,4-D bond between N-acetylmuramic acid and N-acetyl-D-glucosamine of the peptidoglycan in the cell wall. This peptidoglycan is the main component of the bacterial cell wall. The action of safflower oil thus causes the bacterial lysis, that is, the death of the bacteria.

The same applies to fungi. Studies in vitro conducted with Aspergillus niger, Penicillium digitatum and Fusarium oxysporum have shown that safflower oil can reduce the germination of spores of these fungi with a high inhibition percentage of 84.8% for Aspergillus niger and over 88% for the other tested fungi. Therefore, it may be beneficial to regularly apply safflower vegetable oil to the scalp through massage to take advantage of its sanitising effect.

• CHAIYASUT C. & co. Inhibition of 5α-reductase and promotion of hair growth by certain Thai plants traditionally used for hair care. Journal of Ethnopharmacology (2012).

• KUMAR N. & CHAIYASUT C. Promoting Hair Growth Activity of Carthamus Tinctorius Florets Extract Loaded Nanostructured Lipid Carriers. International Journal of Pharmacy and Pharmaceutical Sciences (2015).

• TRÜEB R. M. The impact of oxidative stress on hair. International Journal of Cosmetic Science (2015).