Castor oil is commonly used as an ingredient in skin care products, including lip balms and lipsticks. It’s rich in the monounsaturated fatty acid ricinoleic acid, a known humectant.

Humectants help retain skin moisture by preventing water loss through the outer layer of your skin. Because of these qualities, castor oil can be applied to lips and skin, either on its own or as an ingredient, to promote hydration.

Keep reading to learn more about castor oil and how to make your own lip balm with it as an ingredient.

Castor oil is extracted from the seeds of the Ricinus communis plant by cold pressing. Cold pressing is a way to separate oil from the seeds of a plant without using heat. Once collected, the oil is clarified, or made pure, using heat.

When castor oil is included as an ingredient in cosmetics, it’s typically referred to as Ricinus communis (castor) seed oil.

According to a 2007 study, castor oil was shown to not be a significant skin irritant, sensitizer, or photosensitizer in human clinical tests.

However, a 2008 study, found that some people have an allergic reaction when castor oil is applied to their skin, although it seems to be a rare occurrence.

If you’re thinking about using castor oil on your lips, consider talking with your dermatologist about potential allergic reactions.

Also, consider putting a tiny amount on a small patch of forearm skin before applying elsewhere on your body. Observe the patch for 24 hours. If there’s no reaction, such as redness or itchiness, chances are you’re not allergic to the oil.

Ingestion

There are some risks associated with ingesting castor oil as opposed to putting it on your skin. These include diarrhea and the induction of labor.

Ricin

The same castor beans that are used in the production of castor oil contain the poison ricin. But castor oil doesn’t contain ricin, as ricin doesn’t separate into the oil, according to a 2007 study.

According to the Centers for Disease Control and Prevention (CDC), unless you eat castor beans, it’s highly unlikely for you to be exposed to ricin.

You can apply castor oil directly on your lips, or you can buy or make a lip balm that has castor oil as a main ingredient.

North Carolina State University published a recipe for castor oil lip balm that includes the following ingredients:

  • 1 tbsp. castor oil (you can substitute jojoba oil, olive oil, or grapeseed oil)
  • 1 tbsp. coconut oil
  • 1 tsp. cocoa butter
  • 1/2 tbsp. grated beeswax
  • 1/2 tsp. vitamin E oil

Follow these steps for making the lip balm:

  1. In a medium-sized glass or stainless steel bowl, combine the castor oil, coconut oil, cocoa butter, and beeswax.
  2. Melt the ingredients in a double boiler while stirring with a fork.
  3. When the mixture is totally liquified, stir in the vitamin E oil, then remove it from the heat.
  4. Pour the mixture into a small tin or lip balm tube. Be sure to let it cool and harden before using.

Castor oil has uses beyond skin moisturization. It can be used as:

  • A laxative. When taken orally, castor oil has a strong laxative effect, according to a 2012 study.
  • An anti-inflammatory. According to a 2015 study, the ricinoleic acid in castor oil can reduce inflammation and pain when applied topically.
  • An antibacterial. According to a 2016 study of laboratory mice, castor oil has strong antibacterial activity.
  • An antifungal. Castor oil has antifungal properties, according to a 2013 study that focused on bacteria (Enterococcus faecalis) and fungus (Candida albicans) in mouth and dental health.

Castor oil is considered safe for your skin and lips. It’s a common ingredient in skin care products. Although an allergic reaction to the topical application of castor oil is possible, it seems to be a rare occurrence.

The ricinoleic acid in castor oil helps retain skin moisture by preventing water loss through the outer layer of your skin.

When starting any new skin care regimen, including using castor oil on your lips, it’s wise to discuss it with your dermatologist.