Castor Oil: Uses, benefits and side effects

Weight loss. Hair growth. Acne. These are just some of the things that castor oil has been claimed to help with recently. But what does the science say? Let’s take a look at what castor oil is, and its evidence-based benefits.

What is castor oil?

Castor oil is a plant-based oil extracted from the seeds of the Ricinus communis plant. It’s rich in ricinoleic acid, a unique fatty acid traditionally known for its moisturising and anti-inflammatory properties.

How is it made?

Castor oil is typically made through cold-pressing, where the seeds are pressed to extract the oil without heat or chemicals. This helps preserve its beneficial compounds. For health and beauty purposes, it’s best to choose cold-pressed and hexane-free varieties to avoid added chemicals or solvents.

Is there a difference between castor oil and black castor oil?

Yes, and it mostly comes down to how they’re processed:

• Castor oil: Pale yellow, cold-pressed, and commonly used for skin, hair, and general wellness.
• Black castor oil: Made by roasting the seeds before extraction, giving it a darker colour and a slightly higher pH. Black castor oil is also known as Jamaican black castor oil (JBCO) as the roasting technique was thought to have started in Jamaica.

While some people prefer JBCO for hair care, both types contain the same key fatty acids that provide the main benefits.

What are the benefits of castor oil?

1. Digestive support

Castor oil is well-known as a stimulant laxative. Research shows that ricinoleic acid stimulates the intestines, helping relieve occasional constipation. However, it should only be used short-term, as overuse can cause cramping or dehydration. If you're thinking about using castor oil for this, it’s a good idea to check with a healthcare professional first. 

2. Moisturising properties and skin health

Castor oil is naturally rich in vitamin E and fatty acids, giving it antioxidant and moisturising properties. While research on its direct impact on skin health is limited, it’s commonly used in skincare products to help hydrate the skin and support a healthy skin barrier. 

4. Anti-inflammatory effects

Ricinoleic acid has been studied for its anti-inflammatory properties. Although research is still limited in this area, some promising animal studies have shown that when applied topically, castor oil may help relax smooth muscle like in the uterus and digestive tract. 

5. Hair and scalp health

While scientific evidence is limited, castor oil is commonly used to support hair and scalp health. Its moisturising properties may help reduce hair breakage and protect the scalp, creating an environment that supports healthier-looking hair.

Does using castor oil have any side effects?

Castor oil is generally considered safe when used correctly, but it’s not without potential side effects:

• Internal use (as a laxative): High doses can cause cramping, diarrhoea, and dehydration. It’s not suitable for long-term use.
• Topical use: Generally well-tolerated, though some people may experience skin irritation or allergic reactions. A patch test is recommended.
• Pregnancy caution: Castor oil has historically been used to stimulate labour, so avoid internal use during pregnancy unless advised by your healthcare professional.

How much and how often should you use castor oil?

Topical use for skin and hair:

• Apply a small amount (a few drops to a teaspoon) 1–2 times per week. It’s thick, so a little goes a long way. Mix with other oils like jojoba or coconut for easier application. Always follow the directions for use on the product label.

Castor oil packs (for external use):

• Apply 2–3 times per week for 30–60 minutes to areas like the abdomen or joints. Research is limited, but some people find it supports relaxation and comfort.

The bottom line

Castor oil is a versatile natural remedy with a long history of use  and modern research supports some of its key benefits. From its role as a natural laxative to its ability to moisturise skin and support hair health, castor oil can be a useful addition to your wellness routine when used mindfully.

When using castor oil, ensure you:

• Choose cold-pressed, organic varieties
• Use sparingly, especially when taken internally
• Patch test before applying to skin or scalp
• Avoid internal use during pregnancy 

As with any new supplement or product, if unsure if it is right for you, speak first to your healthcare professional.

Reviewed by the Healthylife health experts April 2025.