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Castor oil is generally safe, though there’s no evidence that it can help eyelashes grow. Some people might get an allergic reaction, so it’s best to test it in another area first.

Castor oil is a vegetable oil that is derived from the bean of the castor tree. The fatty acids that make up castor oil are believed to be extremely nourishing to the skin.

Many people report that with regular application, castor oil has helped them to grow thicker, longer eyelashes and eyebrows. Does it really work?

Castor oil is probably best known as an oral laxative. But it’s long been used by people all over the world for many purposes, including treating acne and inflammation, and reducing wrinkles and age spots.

It’s also a common ingredient in many beauty products, because it can add a hydrating effect to cosmetics without clogging pores or irritating skin.

Before you purchase any castor oil, read the label to confirm that it’s pure castor oil. Castor oil that has been blended with other oils or ingredients may cause irritation, or not produce the result you’re seeking.

There are two types of castor oil that are used for beauty. The first is cold-pressed castor oil, which is clear in color. The second is Jamaican black castor oil, which is dark brown in color.

Jamaican black castor oil has developed a reputation as being the preferred choice in many beauty treatments. But both types of castor oil contain the same properties that may make them beneficial to eyelash growth.

A day before your first eyelash treatment, swatch a small amount of the oil on another part of your skin, like your arm. If you don’t develop any skin irritation, the oil should be safe for use on your eyelashes.

The best time to treat your eyelashes is before you go to bed. To treat your eyelashes with castor oil:

  • make sure your eyelashes are clean and completely free of makeup
  • pick up a small amount of castor oil by dipping a cotton swab gently into the oil
  • delicately run the cotton swab along the top of your lash line, taking great care to not allow any of the oil into your eye (oil that gets in your eye could be extremely irritating and should be washed out immediately with water)
  • wash off the castor oil in the morning with water or makeup remover

There have been no scientific studies that prove castor oil helps eyelash hair grow.

There is evidence that ricinoleic acid, a chemical compound that makes up almost 90 percent of castor oil, might help reverse hair loss. A study found that the protein prostaglandin D2 (PGD2) is present in high levels on men who have male pattern baldness, and is one of the factors that kept the subjects of the study from growing their hair back.

Another study found that ricinoleic acid may help inhibit PGD2 and potentially help scalp hair grow back.

More research needs to be done to understand if ricinoleic acid can be used to treat other types of hair loss.

When applying castor oil to your eyelashes, be very careful that it doesn’t get into your eye. In the event that it does, flush your eye with water.

Castor oil is generally regarded as safe. However, some people may have an allergic reaction to castor oil. It’s best to test castor oil on a small area of your skin 24 hours before applying it to your face.

While many beauty products that promise to grow eyelashes come with a hefty price tag, castor oil remains an affordable and all-natural option.

Castor oil is also easy and generally safe to use. With a little bit of patience and consistency, you could be enjoying longer, more beautiful eyelashes with the use of castor oil.