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Does Onion Oil For Hair Growth Really Work?
Dr Meena Zareie (GMC)
Medically reviewed by
Dr Meena Zareie (GMC)
Updated on October 31, 2024

Using onion oil for hair has been popularised on social media in recent years, leading many to try this DIY hair remedy at home. But is there actually any scientific evidence to back up the use of onion oil for hair growth?

In most cases, it’s unlikely that onion oil will help your hair grow. But some people with specific hair loss conditions may benefit — and there are lots of other ways onion oil could help your hair too. Here, you’ll learn:

  • What types of hair loss onion oil can help with.
  • The benefits and downsides of using onion oil on hair.
  • The best way to apply onion oil.
  • Other effective hair growth remedies.
Table of Contents

Is onion oil good for your hair?

While many essential oils for hair growth have limited evidence to support their use, onion extract is actually fairly well studied. Research shows that onion juice for hair can have several positive effects [1-3]. 

However, onion oil won’t necessarily have the same effect as raw onion juice. When onion oil is prepared from onion extract, not all the components are retained (although the components that are retained become more concentrated). So you won’t necessarily see the same impact from using onion oil as onion juice.

The benefits of onion juice you might also see when using onion oil for hair include:

  • Fighting oxidative stress — Oxidative stress is a damaging process that may play a part in the development of alopecia areata and other types of hair loss [4]. Onion oil may reduce the effects of oxidative stress on your hair [1].
  • Anti-inflammatory effects — Inflammation is a symptom of many common scalp problems, including seborrheic dermatitis and scalp psoriasis. Onion oil may have an anti-inflammatory effect when applied to the scalp [1].
  • Improving circulation to the scalp — Good scalp blood flow is essential for delivering nutrients and oxygen to the hair follicles. Quercetin, a flavonoid found in onions, can dilate the blood vessels and increase blood flow (although this effect is much greater when consumed orally than through topical application) [5].
  • Hair strengthening effects — Sulphur-containing compounds within onion oil can help keep the hair cuticle intact, strengthening the hair fibre to minimise hair breakage [6].

These benefits can help keep your hair strong and shiny — but will onion oil help with hair loss?

Does onion oil help with hair growth?

Woman applying onion oil to scalp

Certain onion oil properties — such as increasing blood flow and fighting oxidative stress — are associated with reduced hair loss in alopecia areata. This condition is characterised by the development of round bald spots on the scalp:

Woman with patchy alopecia areata

One study found that applying onion juice to the bald patches twice a day led to hair regrowth in 94% of male patients and 71% of female patients [2]. Note that this relates to onion juice rather than onion oil — onion juice is the raw juice that seeps out when you cut into an onion, while onion oil is distilled onion essence.

However, if you have male pattern baldness or female pattern hair loss — the most common types of alopecia worldwide — onion oil probably isn’t going to help you reverse balding.

Unlike certain other hair growth oils, no studies have yet shown that onion oil can definitively stop hair loss or stimulate regrowth. So it’s best to stick with tried-and-tested remedies if regrowth is your main goal.

Is rosemary or onion oil better for hair?

It depends on what your hair goals are. Rosemary oil has far more evidence to back its use as a natural remedy for androgenetic alopecia than onion oil, while onion oil may be more likely to tackle alopecia areata [3, 7-8].

Rosemary oil for hair works by blocking the production of dihydrotestosterone (DHT) on the scalp, which is the key hormone that drives male pattern baldness. 

If you’re looking for stronger hair or reduced scalp inflammation, onion oil may be the better choice.

How long does onion oil take to grow hair?

While no studies have yet shown that onion oil can stimulate hair growth, onion juice has been shown to regrow hair if you have alopecia areata. For this condition, studies show that onion juice can start to regrow hair in as little as two weeks [3].

How to make onion oil for hair growth

Frying onions to create homemade onion oil

Onion juice is easy to extract at home, but onion oil requires a little more preparation and homemade varieties may be less effective than using onion juice. Using store-bought distilled onion essence may give you more benefits thanks to the higher concentration of certain active ingredients within onion oil.

Here’s how you can make DIY onion oil at home:

DIY onion oil

You will need:

  • 2 onions
  • 1 cup of carrier oil such as olive oil, coconut oil, or argan oil

Here’s what to do:

  1. Peel and chop the onions.
  2. Gently heat the carrier oil in a pan (you don’t want the onions to burn when you add them).
  3. Fry the onions in the carrier oil over a low heat, stirring regularly. This will encourage the onion to release its juices into the oil. Simmer for around 30 minutes.
  4. Strain the oil to remove the onion.
  5. Allow the oil to cool completely before applying it directly to the bald patches on your scalp.
  6. Store any unused oil in an airtight container.

Will onion oil make my hair smell?

Yes. Although the odour isn’t as strong as onion juice, onion oil can still make your hair and scalp smell. In some cases, the smell can really linger, so be aware of this before you apply any onion products to your hair or scalp.

There are a few suggested ways to reduce the smell of onion in your hair, though none are foolproof:

  • Rinse your hair with lemon juice or apple cider vinegar — These may help to neutralise or mask the onion smell.
  • Rub your scalp with a stainless steel soap bar — Some people have reported this can reduce strong odours (although it hasn’t been scientifically proven).
  • Use a clarifying shampoo — Give your hair and scalp a detox with a deep-cleansing shampoo designed to remove impurities from your hair. 

There are plenty of natural hair growth remedies that don’t leave a pungent smell in your hair. One study found that combining rosemary, lavender, thyme, and cedarwood oils could also stimulate hair growth in those with alopecia areata [9]. While you’ll need more ingredients, this oil blend is less likely to leave an unpleasant smell lingering.

What's the best way to use onion hair oil?

Woman applying onion oil through her hair

To reduce symptoms of alopecia areata, apply crude onion juice directly to the bald patches twice a day. Applying onion oil may also work, but more evidence is needed to confirm this.

To see improved hair strength, apply onion oil to your roots. Use your fingers or a wide-toothed comb to distribute the oil through your hair. Leave it for up to 30 minutes then rinse out.

Don’t forget to wash your hair regularly when using onion products to minimise any lingering smells.

Tried-and-tested alopecia treatments

Even if you have alopecia areata, it’s unclear whether onion oil for hair growth really works. While onion juice has shown promising results, there are plenty of more established ways to stop alopecia areata spreading and minimise balding patches. These include:

  • MinoxidilMinoxidil is a topical hair growth solution that’s suitable and effective for men and women with alopecia areata [10].
  • Topical steroidsSteroid creams for hair loss are one of the first-line treatments for those with alopecia areata, including children [11-12].
  • Contact immunotherapy — This treatment is a medically-supervised provoked allergic reaction designed to suppress the immune response that causes alopecia areata hair loss [13].
  • Antihistamines — Certain anti-allergy drugs can also make atopic alopecia areata symptoms less severe [14].

The best way to get the right treatment for your hair loss — or improve the condition of your hair — is to see a trichologist. They can get to the root of your hair problems and help you find the best, fastest solution.

Book a consultation at the Wimpole Clinic for an accurate diagnosis and access to the best available hair loss treatments. Find your nearest hair loss clinic location.

Does Onion Oil For Hair Growth Really Work?, Wimpole Clinic

FAQs

Find out more about onion oil for hair in these frequently asked questions.

Yes, you can make DIY onion oil to use on your hair, though it won’t be as concentrated (and therefore as effective) as store-bought varieties. Follow the instructions above to learn how to make onion oil for your hair.

It’s normally safe to leave onion oil on your hair overnight, though be advised that this is likely to increase the risk of skin irritation, as well as make the onion smell more likely to cling to your hair and scalp.

It’s best to start with a shorter period (around 30 minutes) then extend this if you’re confident the benefits outweigh the risks.

There’s no evidence that onion oil can thicken hair. However, it may help strengthen your hair fibres, which can minimise breakage and prevent unnecessary hair thinning. 

Onion juice isn’t a magic remedy for hair loss. In fact, there’s no evidence that it can help stop hair loss or promote regrowth in the most common types of hair loss (male and female pattern baldness). So it may be that your hair is continuing to shed despite the use of onion oil.

However, there are reports of scalp irritation after application of onion oil or juice. An itchy scalp can make you more likely to scratch your head, leading to mechanical damage that makes your hair break off. This can appear as an increase in hair shedding.

Dr Meena Zareie (GMC)
Medically reviewed by Dr Meena Zareie (GMC)Updated on October 31, 2024
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