Castor oil and onion juice have been purported to encourage hair growth. Can they promote hair growth – and if they can, how do they work? Is it safe to use these ingredients on your hair? Read on to find out how these two very potent and effective ingredients can help with several hair problems. Also, how to use castor oil and onion juice for hair growth.
Table of Contents:
- What are castor oil and onion juice?
- Castor oil
- Onion juice
- How are castor oil and onion juice affecting hair growth
- Castor oil and hair growth
- Onion juice and hair growth
- How to use castor oil and onion juice for hair growth
- Should I use onion juice and castor oil on dry or wet hair
- Our product recommendations
What are castor oil and onion juice?
Castor oil and onion juice are two standard components of many modern hair care products, but they have been used for centuries for beauty and medical purposes. Here’s a closer look at both of these ingredients.
Castor oil
Castor oil is a thick oil extracted from castor bean (Ricinus communis) plant seeds. It was first used as lamp fuel and then for beauty treatments, and the Oil is believed to have valuable medicinal properties as well.
Castor oil is used to moisturize dry skin as its anti-inflammatory and antioxidant properties help protect skin cells from damage. Research suggests that castor oil increases hair luster. It is also used to reduce dandruff, moisturize the scalp, strengthen hair and improve its texture.

Onion juice
Onion juice - the juice extracted from onions, is an excellent home remedy for many hair problems.
The juice’s antioxidants contain catalase, a compound that prevents graying. Its antimicrobial, antifungal, and antibacterial properties help prevent dandruff caused by fungal infections and other scalp infections. Its anti-inflammatories can moisturize an itchy and dry scalp.
How are castor oil and onion juice affecting hair growth
Onion juice and castor oil contain potent properties that promote hair growth in different ways. Here’s a look at how they work. Although castor oil and onion juice are relatively safe, they can cause a mild allergic reaction in some people. It’s best to conduct a skin test before using these products for hair growth.
Castor oil and hair growth
Massaging castor oil on your scalp can boost circulation, encouraging better hair growth. In many cultures, it is used on the eyelashes and eyebrows to boost their growth. The Oil’s antibacterial and antifungal properties ward off infections on the skin that damage follicles and retard hair growth.

With healthier follicles, hair can grow faster (three to five times faster than the regular growth rate), thicker, and more lustrous. You might start seeing results after as little as six to eight weeks of regular, ongoing use.
Onion juice and hair growth
Onion juice is loaded with sulfur that supports thick and strong hair. Sulfur is also necessary to produce copious amounts of proteins and enzymes – it is even found in keratin, a critical component of hair. When onion juice is massaged into the hair and scalp, there is a boost of sulfur which prevents hair loss and encourages hair growth.
Sulfur in onion juice is also known to stimulate the production of collagen – a critical component for healthy skin cells and hair growth.
Nutrients in the juice of onion can provide extra nutrition to hair follicles and reduce breakage and thinning.
Antioxidants and antimicrobials in onion juice can prevent scalp infections and hair loss.

Researchers have found that regularly using onion juice on the hair and scalp can encourage hair growth in just two weeks. In a study on the effect of onion juice on alopecia areata (a type of hair loss condition), 74% of participants said they had some hair regrowth in as little as four weeks. About 87% of participants said they experienced hair regrowth in six weeks.
Note: Onion juice should not be used to cure baldness or other hair-loss illnesses.
How to use castor oil and onion juice for hair growth
Castor oil is very sticky and thick, so mixing it with an oil like coconut oil can help spread the oil and massage it into the scalp much easier. Leave castor oil on your scalp and hair for 30 minutes, and then wash your hair as usual. You can use castor oil on your scalp and hair once a week.
To use onion juice on your hair, chop up a couple of onions and run them through a juicer. Extract the juice and apply it to your scalp. You can add a few drops of essential oil like lavender or peppermint oil to combat the pungent smell of the onion juice. Leave it on for around 20 minutes and wash it off. Use it two or three times a week for the best results.

Mix equal quantities of these ingredients for a mask that uses onion juice and castor oil. Apply the mixture to your scalp an hour before you wash your hair. This is an excellent mask for thicker, longer, and more lustrous and healthy hair.
Should I use onion juice and castor oil on dry or wet hair
Your hair must be clean and dry before applying onion juice to your hair or scalp. That is because dampness and grease can prevent your scalp from absorbing the nutrients from these ingredients.
As long as your hair is clean, it can be wet or dry before castor oil application. Damp hair might be better than dry hair as it helps absorb the oil faster and more efficiently.

Our product recommendations
WOW Skin Science’s haircare products are created from the best natural products to save you time and the bother of making your own home remedies. All WOW Skin Science products are 100% plant-based, vegan, gluten-free, and free from harmful chemicals.
WOW Skin Science Red Onion Black Seed Oil Shampoo is designed to boost hair growth, restore shine and strength, and combat hair loss problems. The shampoo contains red onion seed oil extract, sweet almond oil, black seed oil, and pro-vitamin B5. The ingredients work together to strengthen hair follicles even as they clarify the hair and scalp.
WOW Skin Science Castor Oil is a cold-pressed formula packed with all the nourishment your hair and scalp need for better hair growth. The formula can also be used on your nails, skin, eyebrows, and eyelashes.

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