Skin and Hair
Does Castor Oil Grow Hair, Brows, or Lashes? Claims vs Research
Does castor oil really make your hair, eyebrows, or eyelashes grow? It is one of the most shared beauty tips online. Many people say that rubbing castor oil on the scalp, brows, or lashes every night makes hair thicker and darker in a few weeks. Some looksmaxxing guides also suggest it for fuller brows and lashes to frame the eyes. Here is what the research actually shows.
What supporters say
Castor oil comes from the seeds of the castor plant. It is thick and sticky, and it has been used on hair for thousands of years. Fans say it feeds the hair root, fills in thin brows, and makes lashes longer. Many before and after photos online show darker, fuller looking hair after regular use.
What the research shows for scalp hair
A 2022 review looked at 22 studies on castor, coconut, and argan oil for hair. It found weak evidence that castor oil can make hair look shinier, and no strong evidence that it helps hair grow. Most of the growth claims come from animal tests or personal stories, not studies in people.
A 2026 review of castor oil in skin care adds one interesting lab finding. The main fat in castor oil, called ricinoleic acid, can block an enzyme linked to male pattern hair loss. But the same review notes that a drug that blocked this same pathway did not help men regrow hair in a real trial. So the idea is not proven.
What about brows and lashes?
A doctor writing for Northwell Health explains that castor oil can make lashes look fuller simply because it coats them in a thick, glossy layer. That is a short term look, not real growth. There is no good evidence that it makes lashes or brows grow longer or thicker.
The risks
Castor oil is fairly safe on the scalp for most people, but it is not risk free:
- Eye irritation. The American Academy of Ophthalmology warns that putting castor oil on or in the eyes can irritate them and even damage the clear front of the eye.
- Infection. Store bought castor oil is not sterile, so getting it in your eyes raises the risk of an eye infection.
- Blurry vision. Its thick texture can smear into the eye and blur your vision for a while.
- Skin rash. Some people get an allergic or irritated rash from it.
- Hair felting. In rare cases, castor oil has caused hair to tangle into a hard mat that could only be fixed by cutting the hair off.
If you still want to try it, a careful approach is to test a small patch of skin first, keep it away from your eyes, and stop if you get redness, itching, or swelling.
What to do instead
If your hairline or crown is thinning, treatments with real research behind them beat any oil. Brows or lashes that are thin or falling out can be a sign of a thyroid or other health problem. There is also a prescription lash treatment approved by the FDA, but it can darken your eyelid skin and even the colored part of your eye. For a quick change in photos, brow gel or a brow tint can make brows look fuller right away.
If you want to know whether fuller brows or a new hairstyle actually changes how others see you, The Face They See lets people of the opposite gender rank your photos for free.
Bottom line
Castor oil can make hair look shinier and lashes look glossier for a while, but there is no strong proof that it grows hair, brows, or lashes. It is mostly safe on the scalp, but it should stay out of your eyes. If you are actually losing hair, proven options beat oil every time.