Castor oil has more than 700 uses cosmetically, agriculturally, and industrially. This vegetable-like oil is an ingredient in a variety of cosmetic products, but there’s an increased interest in using castor oil by itself to treat skin disorders, including stretch marks.

It’s possible that castor oil may help reduce the appearance of fresh stretch marks so they fade better over time. However, research to support this method is lacking. It’s also good to remember that stretch marks are a common occurrence and are a natural aftereffect of skin stretching.

Stretch marks are common occurrences from adolescence through adulthood. Technically, these marks are scars. They happen when the skin is stretched out a lot in a short period of time. During the process, collagen in your skin ruptures, leaving behind stretch marks as it heals.

New stretch marks can be pink, red, or purple in color. They can eventually turn white or brown. Stretch marks often develop around the stomach, upper arms, and hips, but they can occur anywhere the skin is affected.

Hormones and genetics may dictate whether you’ll get stretch marks or not. These scars are commonly seen after:

  • a growth spurt, especially during puberty
  • significant muscle growth from weight training
  • pregnancy
  • significant weight loss or gain

Stretch marks are permanent, but they tend to fade on their own over time. The earlier you treat stretch marks, the less noticeable they may be. There is nothing proven yet to prevent stretch marks, but moisturizing stretching skin makes sense.

Castor oil is a type of vegetable oil made from the Ricinus communis plant. The oil is extracted from the seeds of the plant, and then heated up and processed for commercial use. Castor oil is used in a variety of cosmetics because of its anticaking, cleansing, and emulsifying effects. It’s also popular for its moisturizing effects.

Castor oil is rich in monounsaturated fat, which is a type of “healthy” fat we can eat. Specifically, 90 percent of castor oil consists of a monounsaturated fat called ricinoleic acid. For the skin, this fat helps to balance out moisture while offering extra conditioning effects. This can prevent stretch marks from drying out and looking more obvious over time.

Antioxidant benefits are also possible. These help to prevent free radicals from causing skin damage.

Other skin uses for castor oil include treatments for:

  • acne
  • age spots
  • dry skin
  • ringworm
  • sunburn
  • wrinkles

For stretch marks, apply castor oil morning and night. Gently massage a liberal amount of this oil into your stretch marks. The primary benefit here is deep moisturization from the oil, which will soothe any itchiness and keep your stretch marks from drying out. Keeping these types of scars moisturized will make them less noticeable over time as they fade.

You can make the product more effective by massaging it into your skin, rather than just applying it on top of your scars. This will help the stretch marks heal even better.

Massage as a treatment for stretch marks has been well established, but research backing castor oil is lacking.

Researchers in an article on castor oil published in the International Journal of Science and Research describe the oil as effective for treatment of skin problems, including stretch marks. However, the authors don’t detail exactly how the oil is effective. It’s assumed that the deep moisturizing agents are linked to healing of stretch marks, but not necessarily their prevention.

The Moffitt Cancer Center explains that massaging scars like stretch marks softens and flattens scar tissues while also increasing moisture to the area. Massaging scars in this way is most effective within the first two years when the scar tissues are still evolving.

Another study found that a cream composed of a combination of water and argan oil helped increase skin elasticity in 22 clinical participants, as seen in the epidermis via ultrasound. Such results might point to the potential of other oils, such castor oil.

Research on many common oils, salves, and creams, also called topicals, has shown that at this point no topical is better than another at preventing or reducing stretch marks.

Castor seeds naturally contain a toxic substance called ricin, which can be harmful to humans. However, the oil itself doesn’t have ricin after being processed, so it’s generally considered safe.

As an “oil,” you might be hesitant about using castor oil out of fear that it will clog your pores. However, unlike mineral oils and other clogging products, castor oil isn’t likely to lead to breakouts. This is because the fatty acids contain antimicrobial properties that might actually prevent acne.

Castor oil is considered safe for most people. However, there’s a small chance of a sensitivity or allergic reaction, especially if you have sensitive skin or certain skin disorders. Before applying castor oil to a wide area of stretch marks, you might consider testing the oil on a smaller part of your skin first, like the inside of your forearm. If the test area doesn’t react within a day or two, then you can safely use the castor oil.

Castor oil is just one of the options available for treating stretch marks. Other possible treatments include:

Castor oil shows some promise in the world of stretch mark treatment, but it isn’t foolproof. Like other home remedies, the oil is likely more effective for new stretch marks. If you do try castor oil, give it time to work before moving on to another product — the American Academy of Dermatology recommends several weeks.