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While onion is usually known for its strong smell, it may be time that it’s known for something else: its help in hair care.

Researchers have found that the anti-inflammatory and antimicrobial properties of onions may help you grow your hair or enhance its healthy appearance.

Skeptical? Want to know more? Keep reading for more information on the hair-enhancing properties of onions.

A 2018 study published in the Journal of Drug Delivery and Therapeutics took a look at the onion’s ability to improve hair growth.

The study’s researchers created an onion shampoo by:

  • gathering 100 grams (about 3.5 ounces) of fresh onion bulbs
  • cutting them into small pieces
  • using a food processor to chop the onion into even smaller parts
  • filtering the onion extract by pouring the chopped onion over a muslin cloth

They then added the onion extract (usually anywhere from 1 to 3 milliliters) to a natural shampoo of coconut, castor, and eucalyptus oils as well as cleansers.

They found when applied to skin for 5 minutes (much longer than your usual shampoo), the mixture didn’t irritate the skin. They also found that the onion shampoo:

  • provided more nutrients and better nourishment to hair follicles
  • moisturized dry hair and scalp
  • promoted hair growth

You can use this same process to add onion extract to your own shampoo

Even if you’re not ready to start making shampoos, you can use the same process the researchers used to make an onion extract to add to your own shampoo at home.

Don’t worry, your hair won’t smell like onions

And if you’re wondering whether your hair will smell like onions indefinitely, there’s good news.

The researchers used fragrances and a small amount of lemon juice to conceal the smell. When they used the shampoo, they didn’t note a “characteristic smell” of onions.

No peer-reviewed evidence exists on the concept of onions reversing the process of graying hair. However, a lot of home remedies promise onion extract can help reduce gray hairs.

The idea behind these home remedies is that onions contain an antioxidant compound called catalase that helps reduce hydrogen peroxide at the hair roots. This is thought to keep the hair from turning gray.

If you’re willing to give this home remedy a try, here’s a mixture that you can apply three to four times per week:

  • Combine 3 tsp. onion juice with 2 tsp. lemon juice.
  • Apply mixture to hair and scalp as evenly as possible.
  • Leave on hair and scalp for 30 minutes.
  • Rinse and use a mild shampoo to reduce any onion smells.

Alternatively, you can soak a cotton pad in plain onion juice and apply the juice to your scalp, massaging as you apply. Rinse with a mild shampoo after 15 minutes.

Onions contain many compounds that may help to enhance dry, damaged hair.

Examples include flavonoids, such as kampeferol and quercetin. These have anti-inflammatory, antioxidant, and vasodilatory (widening of the blood vessels) properties that help promote blood flow to the scalp.

While admittedly there aren’t a lot of commercial onion-containing hair care products on the market, you can find a few. These ready-made options can help you easily incorporate onion’s benefits into your hair.

To purchase online, click on the individual links provided below:

Onion’s anti-inflammatory properties may help soothe an itchy scalp. You can also combine onion extract with other natural ingredients to calm your scalp.

Some combinations to try include:

  • 2 tbsp. onion juice and 1/2 tbsp. raw honey
  • 1 tsp. olive oil and 3 tsp. onion juice
  • 3 tbsp. onion juice, 5 tsp. coconut oil, and 1 tsp. lime juice

You can apply one of these combos to your scalp, then wash it away with a mild shampoo after about 20 to 30 minutes.

Alopecia areata is a hair condition that causes hair loss in patches.

A 2014 study of 38 people tested the effectiveness of using onion juice to treat alopecia. The researchers had one group of people apply onion juice to their scalp twice a day, while a control group applied tap water.

After 6 weeks, 86.9 percent of those who applied onion juice noticed more hair growth. Only 13 percent of the tap water group noted hair growth.

The researchers concluded onion juice can be a good alopecia treatment.

Onion juice has antimicrobial and antifungal properties, which is why some natural health experts advocate for it as an infection treatment.

Many people experience dandruff due to a fungus called Malassezia furfur, so onion’s antifungal properties could definitely come in handy as a dandruff fighter.

Because there isn’t a lot of research on onion as a dandruff fighter, though, it’s not really a first-line treatment for moderate to severe dandruff. If you have the occasional flakes, however, you could try applying onion juice to your scalp.

You can also experiment with potential dandruff-fighting combinations. Examples include:

  • grinding 2 tbsp. fenugreek seeds and soaking them in 2 tbsp. onion juice and water to make a paste, then applying to your scalp for 30 minutes before rinsing off
  • mixing 2 tbsp. aloe vera gel and 3 tbsp. onion juice, then applying to your scalp for 10 minutes before rinsing off

If your hair is super smelly after using an onion juice preparation, you can follow up with a mild shampoo and apple cider vinegar rinse. To do this:

  • Pour 2 tbsp. apple cider vinegar into 1 cup water.
  • Rinse the solution through your hair when you finish showering.

Using onions on your skin isn’t a good idea if you’re already allergic to onions you eat. Steering clear may help you avoid further allergic reactions.

Also, if you have sensitive skin, it’s possible that onion juice could irritate it. The key is not to leave it on too long. This means keeping it on overnight is a no-no if you do happen to have sensitive skin or a sensitive scalp.

As with any product or treatment, if onion extract irritates you, stop using it.

You can use onions to improve your hair in lots of ways. These include reducing dandruff and potentially promoting hair growth.

When you’re feeling crafty or experimental, try some of the DIY onion hair care recipes included in this article and see if you can reap onion’s hair-boosting effects.