Nails face daily stressors: keyboard typing, nail polish application and removal, and household cleaning products. These stressors can weaken, soften or split nails. To address these problems, some people use castor oil. Is this plant oil effective at strengthening nails? Learn more in this article.
How can castor oil support nail health?
Published on May 13, 2022, updated on July 3, 2025, by Maylis, Chemical Engineer — 6 min of reading
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How does castor oil work on nails?
The castor oil is a plant oil obtained by cold pressing seeds of the common castor shrub in the Euphorbiaceae family. Common in skin care, the castor oil is a liquid with an oily texture, a clear to yellow color, and a mild odor. It has a potential effect on the growth of hair, but it offers numerous benefits for hair, as well as for eyebrows, eyelashes, beard, and skin. Moisturizing, nourishing, soothing, antibacterial. The castor oil is a plant oil valued in skin care for its versatility.
Castor oil is also valued for nail care. However, to date, no scientific study has proven its benefits for nails.
Despite the lack of clinical studies, several factors suggest that regular use of castor oil on nails and cuticles could help strengthen them:
Castor oil to strengthen nails.
Castor oil is valued for its ability to strengthen nail structure. It is suggested to penetrate keratin, fill microcracks, and improve layer cohesion, reducing nail fragility. Castor oil may fortify the nail plate and prevent brittle nails, ridged or damaged. A study in vitro showed that castor oil can stimulate keratin production in hair follicles, increasing hair strength and resilience. Cautious extrapolation suggests it may support keratin synthesis in nails, although this remains to be confirmed.
Castor oil to help prevent fungal infections of the hands and feet.
Castor oil also exhibits antifungal properties. Ricinoleic acid, its main fatty acid, inhibits the growth of certain fungi responsible for nail infections, such as Cunninghamella bertholletiae. One study compared castor oil activity to standard antifungal agents using disk diffusion and minimum inhibitory concentration (MIC) tests. Castor oil showed an average inhibition zone of 22.44 mm, compared to 20.66 mm for amphotericin B, with a comparable MIC (1.72 µg/ml for castor oil versus 1.66 µg/ml for amphotericin B). These data suggest castor oil may help limit nail fungal infections, but clinical studies are needed to confirm this.
Castor oil to hydrate nails and cuticles.
The cuticle is the thin flap of skin that surrounds the nail on both hands and feet and which comes to cover and protect its base. It acts as a first barrier against external damage and infections. Rich in fatty acids, castor oil helps hydrate this often neglected area and prevent cracking. It hydrates nails, making them more lustrous.
Castor oil to protect nails from oxidation.
In addition to fatty acids, castor oil contains vitamin E, a potent natural antioxidant. This vitamin helps neutralize free radicals generated by repeated exposure to external stressors such as UV rays, pollution, or certain chemical agents found in detergents. Castor oil helps limit lipid oxidation in nail keratin, which helps preserve structure, strength, and color. Oxidative stress can dull nails and cause yellowing.
Castor oil to stimulate nail growth.
Castor oil is promoted as a solution to stimulate nail growth. However, no scientific study has established a link between castor oil application and accelerated nail growth. We can assume that by hydrating the nails, nourishing them, and strengthening the nail plate, castor oil creates favorable conditions for growth and reduces breakage.
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How can you optimize castor oil’s effects on nails?
To benefit from castor oil’s potential on nails, it must be applied regularly. Indeed, as with many in skincare, consistency is essential to achieve results. Castor oil can be applied daily to each fingernail and toenail using your fingertip or an applicator brush. Massage the nails in circular motions. Alternatively, perform a bath of castor oil one to two times per week. Pour the oil into a bowl and soak the nails for about fifteen minutes. Massage the nails before rinsing and drying them.
Tip Once or twice a week, you can coat your nails with castor oil before wrapping them in cellophane overnight.
Sources
AZADMARD-DAMIRCHI S. & al. Physiological and medicinal properties of castor oil. Recent Progress in Medicinal Plants (2011).
BERKER D. Nail anatomy. Clinics in Dermatology (2013).
MARWAT S. K. & al. Review - Ricinus communis - ethnomedicinal uses and pharmacological activities. Pakistan Journal of Pharmaceutical Sciences (2017).
IQUBAL S. & al. Efficacy of phytochemical constituents of Castor essential oil towards the mucor-mycotic mold Cunninghamella Bertholletiae. Journal of New Developments in Chemistry (2020).
ROY D. & ROY R. Exploring natural ways to maintain keratin production in hair follicles. Journal of Emerging Investigators (2024).
