Should You Use Onion Juice for Gray Hair? Is It Effective?

Certified Senior Advisor®
Senior Home Safety Specialist®
20 years of medical equipment experience
Compassionately helping seniors and their caregivers solve challenges of aging

Onion juice is a popular home remedy for gray hair and it has been believed to reverse the graying process. When applied topically, it is thought to improve blood circulation to the scalp and stimulate hair growth. Let's take a closer look at the science behind it to find out if these claims work.

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Onion Juice for Gray Hair

The tell-tale signs of aging can be difficult to accept. One of the more common indications of getting older is when your hair starts to gray. While some people embrace their new look, others scramble to find ways to cover up the gray.

Among others, using onion juice for gray hair has become a popular method. You may have heard of it from a friend or someone else, but the question remains – does it work?

Onion Juice for Gray Hair: The Effectiveness

If you are looking for an all-natural way to help slow down the progression of gray hair, then onion juice may be a good choice for you. It is affordable, easy to find, and comes with a variety of other benefits for your hair health. However, it is important to note that more research is needed to assess its full effectiveness as a treatment for gray hair.

Onion Juice for Gray Hair: The Science

The science behind using onion juice for gray hair is that the sulfur in onions helps to produce melanin, which is responsible for giving your hair its color. When onion is applied to the scalp, the hair follicles absorb the sulfur, and thus melanin is produced. Up to this writing, there has not been any scientific study conducted on humans that proves onion juice can reverse hair graying.

Instead, it can help slow down or stop the progression of gray hair in some people. The superfood’s potent chemical ingredient called quercetin can actually help protect against hydrogen peroxide buildup and thus restore some of its natural colors by creating a barrier that prevents further destruction from this element. Furthermore – in addition to preventing gray hairs – it also has been proven able to increase shine as well as strength for healthier strands!

While it may not completely turn your gray hair and restore its original color, onion also comes with a multitude of benefits for your hair. A study in 2018 has shown that onion juice can improve the quality of hair and scalp health. It helps promote hair growth, can prevent hair loss, and can also help stimulate your scalp.

The study found that onion juice has anti-inflammatory, antimicrobial, and antioxidant properties,. which all work together to improve scalp health.

Other benefits of onion on your hair may include but are not limited to:

  • Protection from the sun’s UV rays
  • Prevention of split ends
  • Reduced dandruff
  • Hair growth

How to Use Onion Juice for Gray Hair

For this process to work, you will need:

  • One onion, preferably red
  • A juicer or blender


1. Peel the onion and cut it into small pieces.

Have a box of tissues on standby!

2. Juice it with a juicer or blender.

If you are using a juicer, the juice will be collected in one container and separated from any pulp or sediment that may have come into contact with it during the process. If you are blending, then the blended onion will contain the juice and pulp.

3. Strain the mixture to get just the juice (optional).

Blended onion will need to be strained and separated to get the juice unless you don’t mind the bits of onion pieces in your hair. Or, you can strain it through a cheesecloth or fine metal mesh sieve to remove any large pieces.

4. Dilute with water.

After you have strained the onion juice, then mix it with an equal amount of water before applying it to your scalp as above.

5. Apply to the scalp.

Apply the diluted juice directly to your scalp and massage it well. Leave it on for 30 minutes before rinsing off with your favorite shampoo and conditioner for gray hair.

6. Repeat as needed

You can repeat this treatment up to three times a week.

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Red onions are preferred over white onions because they contain more quercetin molecules (the active ingredient).

Risks and Warnings

Of course, you should always be aware of any potential risks when using substances on your body. While onions are generally safe, here are a few risks you should be aware of:

Take care to avoid touching your eyes when handling onions. The juice can cause irritation if it comes into contact with your eyes.

Wear gloves when juicing or blending the onion to avoid any skin irritation.

If you do get some of the juice in your eye, rinse it out immediately with cold water.

Another thing to consider if you are using onion juice for gray hair is that it may cause your scalp or skin to be more sensitive to the sun. This means that you should wear sunscreen, protective clothing, and hats when spending time outdoors in order to lower your risk of developing skin cancers.

If you are using onion juice for gray hair, then it is recommended that you use either red or yellow onions. White onions will not work as well as it contains fewer quercetin molecules.

Onion juice can also be used as a hair rinse. Mix it with an equal amount of water and use it after shampooing. Leave it on for two to three minutes before rinsing off. You can do this treatment up to twice a week.

Is It Safe to Apply Onion to Your Scalp?

Yes, it is safe to apply onion juice directly to your scalp. However, some people may experience skin irritation or an allergic reaction when using it. If you do experience any adverse effects, stop using the juice and consult with your doctor.

You can do a patch test to check for any allergic reaction before applying the onion juice. Apply a little bit of it on your inner arm and wait 24 hours to see if you develop any signs of irritation, such as redness, itching, or swelling.

You can also test for any allergic reaction by applying a small amount of the juice behind your earlobe where there is less skin sensitivity.

On very rare occasions, you may experience anaphylaxis, a serious allergic reaction that occurs when your immune system overreacts to the allergen. Symptoms of this can include difficulty breathing, hives or welts on your skin, dizziness, and/or fainting. After using onion juice, seek medical attention immediately if you have these symptoms.

Certified Senior Advisor (CSA)®
Senior Home Safety Specialist (SHSS)®
Assistive Technology Professional

Scott Grant has spent more than 20 years serving seniors and the elderly in the home medical equipment industry. He has worked as a manufacturer's rep for the top medical equipment companies and a custom wheelchair specialist at a durable medical equipment (DME) provider in WV. He is father to 4 beautiful daughters and has three terrific grandkids. When not promoting better living for older adults, he enjoys outdoor activities including hiking and kayaking and early morning runs.

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