One Oil. All Winter

Organic Castor Oil in Winter: What the Evidence Actually Says

Every winter, the same thing happens. The air gets colder and drier, and your body feels it. Skin that felt fine in summer suddenly feels tight and dull. Hair becomes brittle and loses its lustre. Nails crack. Cuticles split.

Itchy. Scaly. Flaking. Splitting. Cracking. 

Cold, dry conditions deplete the skin's natural moisture barrier, affect the scalp, and leave nails and cuticles vulnerable. It is worth understanding what the evidence says about how to support your body through this.

What makes Castor Oil different?

Around 90% of castor oil is made up of ricinoleic acid, a rare omega-9 fatty acid found in almost no other natural oil. It is this unique composition that has attracted growing scientific interest. Ricinoleic acid acts as a humectant, drawing moisture in and maintaining it. It also has well-documented anti-inflammatory and antimicrobial properties.

For Skin

Cold, dry air depletes the skin's natural moisture barrier. A narrative review published in Cureus (2026) confirmed castor oil's efficacy in improving skin hydration, elasticity, and signs of ageing through its antioxidant properties.¹ The ricinoleic acid in castor oil acts as a humectant, locking moisture into the skin and preventing water loss through the outermost layer, helping keep skin hydrated and soft.²

Research also points to castor oil's potential in reducing the appearance of under-eye hyperpigmentation. A 2023 clinical trial found that creams containing castor oil appeared to be an effective treatment alternative for infraorbital hyperpigmentation, though the authors noted that further research is needed to confirm findings.³

It is particularly effective on dry areas like elbows, knees, heels, and lips. A small amount goes a long way.

For Hair and Scalp

Winter conditions accelerate scalp dryness and can worsen hair fragility. Evidence supports castor oil's use in hair care for improving lustre and possibly combating androgenic alopecia via inhibition of prostaglandin D2 synthesis.¹ Applied to the scalp, it helps support the environment where hair grows and addresses the dryness and flaking that winter conditions tend to accelerate.

For eyebrows and eyelashes, castor oil has traditionally been used as a conditioning treatment. Evidence supports its role in maintaining hydration and flexibility of the hair shaft, keeping lashes and brows soft and resilient through the colder months.⁴

For Nails and Cuticles

This is where castor oil quietly excels in winter. Research shows that castor oil, rich in fatty acids, helps hydrate the cuticle and prevent cracking. It also contains vitamin E, a potent antioxidant that helps neutralise free radicals and limit oxidative stress in nail keratin, preserving structure, strength, and colour.⁵

Brittle, peeling nails in winter are often simply dehydrated. Regular application to the nail bed and surrounding skin is a simple, evidence-supported step that makes a noticeable difference within a few weeks.

Why hexane-free matters

Not all castor oil is the same, and the extraction method makes a significant difference. Most commercial castor oil is extracted using hexane, a petroleum-derived chemical solvent used to increase oil yield. Trace amounts of hexane can remain in the final product, and hexane is a known neurotoxin, meaning that prolonged exposure, even in small amounts, can be harmful.

Oils extracted using hexane involve a chemical process that exposes the oil to high temperatures, potentially degrading its natural nutrients. Choosing a hexane-free, cold-pressed castor oil ensures you are using a product closer to its natural form, free from unwanted contaminants, and retaining all of the oil's beneficial properties.

How to use Organic Castor Oil this winter

Shop Mister Jones Organic Castor Oil

Always patch test before use.
If irritation occurs, discontinue use.
This article is for informational purposes only and does not constitute medical advice.