Onions are known for their intense smell and strong flavour. For this reason, it’s not exactly a common ingredient in shampoos or other hair products. So it’s perhaps surprising that more people are turning to onion juice for hair growth.
But before you raid the kitchen, it’s important to establish whether onion juice for hair actually has any benefits for improving hair loss or enhancing hair texture. While some studies suggest onion juice for hair can in fact help treat certain types of alopecia, more research is needed to confirm this [1-2].
In this article, you’ll learn the scientifically proven benefits of using onion juice on your hair and scalp, including:
Some studies have shown that onion juice may help improve hair growth in those affected by alopecia areata [1-2]. This is an autoimmune condition characterised by the development of round bald patches on the scalp. Sometimes this can also affect the beard and/or eyebrows.
One small study found that treating alopecia areata with onion juice led to hair regrowth in 87% of patients after six weeks [2]. By comparison, only 13% of the placebo group saw regrowth after eight weeks. So onion juice may be a promising natural hair growth treatment for alopecia areata.
Alopecia areata affects around 1 in every 170 adults in the UK [3]. So while it’s relatively common, it’s nowhere near as prevalent as male pattern baldness, which affects up to 95% of men by the age of 80 [4]. And unfortunately there’s no direct evidence that onion juice can reverse balding caused by pattern baldness.
That said, onion juice may offer some benefits for your hair, thanks to its nourishing properties.
It’s not yet clear how long you’ll need to use onion juice for best results, or the best way to apply it at home. But the evidence below can give you an idea of what to expect from using onion juice for hair growth and other improvements.
Oxidative stress damages your cells, which can make your hair fall out and age prematurely [5]. Onions are an excellent source of flavonoids, antioxidant-rich compounds that can help fight oxidative stress [6].
Oxidative stress is a well-known marker of alopecia areata [7]. But it also plays a part in the development of androgenetic alopecia (though to a lesser extent than other factors like hormones and genetics) [8]. So applying antioxidant-rich onion juice to your scalp regularly may reduce hair fall caused by increased oxidative stress.
Certain common scalp problems (such as scalp psoriasis) can cause inflammation around the hair follicles, contributing to hair loss and tenderness on the scalp. Onion juice contains several anti-inflammatory compounds, including tannins, flavonoids, and saponin.
Some studies have found that the anti-inflammatory properties of onion are comparable with chemical anti-inflammatories, so applying onion juice to inflamed areas may be an effective way to treat scalp inflammation and related hair loss naturally [6].
Onion juice is rich in quercetin, a flavonoid that may help widen blood vessels and improve circulation [9]. Boosting scalp blood flow is a common method of inducing hair growth (Minoxidil, a common hair loss treatment for men and women, acts as a vasodilator). So it’s possible that applying onion juice will also increase blood flow and stimulate regrowth.
That said, the effects of quercetin are greatest when consumed orally rather than applied topically. Topical application of onion juice may only slightly increase blood flow, as quercetin can’t penetrate the skin barrier easily.
Onion has a high sulphur content [1]. Sulphur compounds have been shown to strengthen human hair by keeping the hair cuticle intact [10]. This is essential for minimising hair breakage caused by damaging practices like heat styling, sun exposure, and chemical hair treatments.
In addition, sulphur-containing compounds can promote circulation and reduce inflammation, boosting the healthy hair properties of onion juice.
Onion is a great source of vitamin C. When ingested, vitamin C for hair promotes collagen production, which is essential for healthy hair [11]. Topical application may not work in the same way, so it’s unclear whether onion juice will produce more collagen for your hair. But eating onions will — so make sure you’re eating plenty in any diet for healthy hair.
Vitamin C is also needed for iron absorption, which is necessary for hair growth and a glossy texture. Iron deficiency is relatively common, so find out how a lack of iron can affect your hair.
Scientific before and after comparisons of onion juice for hair growth are limited. One study found that 20 out of 23 alopecia areata patients saw hair regrowth after applying onion juice to their scalp twice a day for six weeks, but no photographic evidence is available to show the visible extent of this regrowth [2].
There is, however, some anecdotal evidence about the effectiveness of onion juice for hair. There’s no guarantee of consistent application or valid testing in non-clinical environments, so bear this in mind if you’re considering trying onion juice on your hair and scalp.
One YouTube user claimed that using onion juice for just seven days visibly reduced hair fall after applying onion juice, and in the shower when washing her hair:
Here’s how the user describes her routine:
“I always apply this hair treatment on dry detangled hair, then use half a cup of onion juice from the main batch on each application. Then I apply the onion juice mostly on my scalp and if I have any left, I use it on the rest of my hair. Cover my hair and wait for an hour. At the end I rinse out the onion juice treatment using only cool water. Air dry hair. Then repeat the same steps for the next seven days.”
She also reported improvements in hair quality over the seven days, with her hair feeling soft, shiny, and strong from root to tip.
See the full video for more details:
To extract onion juice for your hair, you’ll need:
Here’s how to make onion juice:
Top tip: Freeze onion juice in ice cube trays for future use.
Here’s how to use onion juice for hair growth:
While anecdotal evidence suggests you can see a difference after just seven days of application, if you want sustained hair growth, you’ll need to apply onion juice to your hair twice daily for at least four weeks [2]. This applies to alopecia areata patients in particular, but is also likely to apply to those with other types of hair loss.
Grey hair may benefit from onion juice, though the research is very limited. There’s no real way of preventing hair ageing, though regular onion juice applications may provide some minor benefits. For example:
While onion juice has plenty of benefits for hair, it’s probably not the best or easiest way to encourage hair growth. Many other products have more substantial evidence to back up their effectiveness as a hair loss treatment (and won’t leave the same lingering odour).
If you’re serious about tackling your hair loss, book a consultation at the Wimpole Clinic. While we’ve been voted Hair Transplant Clinic of the Year four years running, we offer more than just FUE and FUT hair transplantation.
Our team of hair loss specialists can analyse the cause of your shedding, then formulate an individual treatment plan to slow, stop and even reverse hair loss. Recommended solutions may include Minoxidil, Finasteride, and other proven non-surgical hair restoration treatments, and we’ll be happy to discuss the pros and cons of surgery if you’re considering this too.
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