The use of onion juice for hair growth might have become a popular trend for those seeking a remedy for unexplained hair loss. Onion juice, quite simply, is pressed from the onion plant, which comes in a variety of species in the Allium genus.
One of the most widely available vegetables in the world, onions may contain a rich supply of vitamin C, various B-family vitamins, sulfur, calcium, iron, potassium, manganese, phosphorus, and magnesium, as well as other antioxidants, phenolic compounds, and anthocyanins. This dense nutrient profile can have a number of positive effects on the body, including hair growth.
Benefits of Onion Juice for Hair Growth
The top benefits of using onion juice may include its ability to moisturize the skin, improve follicle health, prevent infection, relieve inflammation, slow the graying of hair, and stimulate circulation. 
May Improve Circulation
The active ingredients in onions might increase circulation under the skin, which can drive important nutrients and oxygen to the hair follicles, thus stimulating hair growth and improving healing. 
Can Help Reduce Inflammation
The antioxidants in onion juice may make it ideal for soothing inflammation of the scalp, which can often lead to dry skin or impaired function of the hair follicles. By reducing this inflammation, you can cut down on dandruff and lower your chance of infection from open wounds. 
Might Prevent Graying of Hair
Onions possess an antioxidant enzyme called catalase, the lack of which can lead to premature graying of the hair. Without this compound, hair might become weaker and is more likely to fall once it changes color; the regular application of onion juice for hair growth can help ensure this doesn’t happen. 
Might Protect from Infection
Various fungal, bacterial or viral infections can affect the scalp and lead to hair loss, and also impede further hair growth. Onion juice has a number of antibacterial and anti-fungal properties that may offer the required protection against pathogens that can lower hair follicle function. 
Can Help Moisturize the Scalp
Onion juice may have an invigorating and moisturizing effect on the scalp, which can help prevent dry skin and provide the hydration that hair follicles need to grow. 
May Improve Follicle Health
Onion juice is extremely dense in nutrients and minerals, many of which the hair requires to grow, such as sulfuric compounds. Directly massaging onion juice into the scalp and hair may stimulate hair growth from unhealthy follicles and maintain normal growth from healthy follicles. 
How to Make Onion Juice?
It is popular to make your own onion juice for hair growth at home, as it isn’t the most common vegetable juice on the market. Let’s take a look at how to make onion juice at home by following the easy recipe given below.
How to Make Onion Juice: Easy Recipe
- 2 yellow onions  (large)
- To make onion juice, first, peel off the onions. After thoroughly cleaning them under running water, get rid of all types of dirt on the skin. Dry the onions using a towel and then peel them. Chop them into quarters or even smaller chunks.
- Add the onions to your blender and blend them till all you see is a thick paste. Strain the juice through a sieve or cheesecloth. Press the onion pulp to extract as much juice as possible.
- Once done, refrigerate the onion juice until you are ready to use it.
How to Use Onion Juice for Hair Growth?
Although most people consume vegetable juice for its many health benefits, you should topically apply onion juice for hair growth, as this is a more direct way of delivering the nutrients to the areas of your body that need it most.
- Step 1 – Massage the onion juice into the scalp and any bald patches that may be appearing.
- Step 2 – Leave the onion juice in your hair for 15-20 minutes.
- Step 3 – Wash out the onion juice with warm water and a mild shampoo.
- Step 4 – Repeat this process daily for best results.
Note: You may add honey to the onion juice to increase its efficacy and further enrich your hair follicles.
Side Effects of Onion Juice
There are some notable side effects of using onion juice for hair growth, including an itchy scalp, eczema, and even a burning sensation, as well as the potential for allergic reactions.
- Itchiness and Burning: Due to the high sulfur content found in onion juice, it is known to create itchiness on the scalp, which can escalate to a burning sensation and excessive scratching. This can lead to more inflammation, open wounds that are ripe for infection, and an increase in dandruff and dry skin, none of which help symptoms of hair loss.
- Eczema: Topical scalp eczema has been reported in people with sensitive skin who use onion juice for hair growth. Speak with a doctor before using this juice if you have sensitive skin on other parts of your body.
- Allergic Reactions: Some people do have topical allergies to onions, and while most people are likely aware of these allergies, the concentrated nature of onion juice may have unexpected side effects, such as inflammation, hives, and rashes on the hands and scalp.