Does castor oil help acne?

Castor oil has a long history of therapeutic and cosmetic use. It has recently seen a surge in popularity as a skincare topical, thanks in part to social media trends. As a topical natural product, castor oil is widely believed to treat and prevent acne, while also reducing wrinkles and moisturizing skin to improve overall appearance.

Let’s investigate the reasoning behind these claims and whether or not they hold up to scientific scrutiny.

What is castor oil?

Castor oil is a plant oil derived from the castor bean, which comes from the flowering shrub Ricinus communis. The oil is extracted from the bean using mechanical and/or chemical means, yielding a thick, viscous yellow liquid.

The castor plant is native to India and Eastern Africa, but is now grown worldwide to meet the increasing demands in both therapeutic and industrial applications. Castor oil has been used by humans since ancient times, especially in Ayurvedic medicine.

Castor oil is composed of 90% ricinoleic acid. Ricinoleic acid is a fatty acid, which is thought to be responsible for most of the therapeutic benefits of castor oil. Ricinoleic acid is special because it bears a strong resemblance to something called prostaglandins. Prostaglandins are endogenous lipids which have important physiological activities in the body, akin to hormones.

Other significant bioactive constituents of castor oil include polyphenols, phytosterols, and tocopherols, as well as additional fatty acids.

Castor oil and/or its individual bioactive constituents have been scientifically shown to have the following properties:

• Antifungal
• Antibacterial
• Antioxidant
• Anti-inflammatory
• Emollient
• Moisturizing

The theory behind castor oil for acne and skincare

Here is the theoretical framework suggesting that castor oil can improve acne:

Antibacterial: Because castor oil has antibacterial properties, it is possible that it can reduce acne-causing bacteria. Specifically, Propionibacterium acnes, or P. acnes, is a bacterium that contributes to the formation of acne. People who are genetically prone to acne tend to produce more sebum, which gets broken down by acne-causing bacteria to cause break-outs. Castor oil may help by inhibiting the bacterial activity.

Antioxidant: Castor oil contains forms of vitamin E, which have antioxidant properties. The anti-oxidant property of castor oil could help to slow down sebum oxidation, which could also improve acne. Additionally, antioxidants can improve signs of aging by reversing oxidative stress from environmental aggressors (like UV exposure).

Anti-inflammatory: Inflammation is a major component of acne. Castor oil may have the ability to reduce the inflammatory response, which can improve the appearance of skin. Theoretically, the anti-inflammatory action combined with the moisturizing properties of castor oil could also mitigate hyperpigmentation. Hyperpigmentation is the discoloration that occurs after acne has healed.

Moisturizing: People with oily, acne-prone skin may be tempted to shy away from moisturizers, but this can actually be detrimental to skin. Finding a moisturizer that does not irritate the skin or cause break-outs is an important part of rebuilding a healthy skin barrier. Castor oil has moisturizing properties that could fill that void for some people. When skin is moisturized, it appears healthier and clearer due to light-scattering effects on the stratum corneum, the outermost layer of the skin.

The science behind castor oil for skincare

When used properly, hydrogen peroxide can be an effective biocide against several microorganisms, including:

Unfortunately, we still don’t have quality randomized clinical trials to unequivocally show that castor oil can help with acne or other skin conditions. What we do have is anecdotal evidence and the theory described above.

Although all-natural skin-care solutions like oils and herbs are attractive, formulation often plays an important role in skincare products. Castor oil theoretically has all the perfect properties for treating acne, but in practice, there are a lot of variables to consider. Without controlled clinical trials, we cannot know that the right components will be in the right place at the right time.

For example, we don’t know how well the individual components will permeate the protective stratum corneum. We don’t know how castor oil will interact with the skin microbiome, including the enzymes that are responsible for breaking down lipids.

Many of the valuable topical properties of castor oil are attributed to fatty acids, like ricinoleic acid. But castor oil contains very few fatty acids in their free form – less than 0.3%, to be precise. Most of the fatty acids are bound up in triglycerides, a glycerol backbone bound to three fatty acids. Only when an oil begins to go rancid are the free fatty acids released from triglycerides.

There is a chance that lipases (enzymes that break down lipids) that live on your skin can break down these triglycerides to release the free fatty acids, but we don’t know for certain.

In other words, we can’t rely on castor oil to have all the properties of its free fatty acids without clinical trials.

Is castor oil safe?

Yes, castor oil is perfectly safe to use. Although the bean itself is poisonous, the extraction and purification processes ensure that by the time it gets to you it is safe enough to use on your skin, and even to drink in small quantities.

There is a slight risk of developing contact dermatitis – effectively, developing an allergy to a topical ingredient. Sometimes, this can be difficult to identify because it can occur after you’ve already been using the product for a while. However, this phenomenon is not unique to castor oil.

Rancid castor oil, or castor oil that has begun to go off, poses more of a risk for contact dermatitis. We recommend purchasing fresh castor oil periodically, and storing it in a cool, dark place.

How to use castor oil for skin

If you’d like to try castor oil for your skin, you may wish to mix it with a carrier oil. Castor oil is extremely thick and viscous, and therefore it can be difficult to spread. You can experiment with jojoba oil, olive oil, almond oil, or anything that works well with your skin.

If you have additional questions regarding castor oil or any of our products, please feel free to contact us for more information.