What is Onion Shampoo? And Does it Work For Hair Growth?
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French onion soup? Delicious. Adding a grilled onion to your burger? Chef’s kiss. The latest TikTok trend? Incorporating onions into a hair care routine. Yup, you read that right. Onion extract in shampoo may actually be beneficial for your strands, according to experts.
“Onions are naturally antimicrobial while rich in sulfur and antioxidants so there is truth in onion being potentially helpful as an ingredient in hair products,” says Dr. Anna Chacon, a board-certified dermatologist in Miami, Florida. Because of this, there are a number of shampoos on the market that list onion extract as one of their primary ingredients.
Below, we spoke to experts about the potential benefits associated with onion shampoo, whether you can use it if you have color-treated hair and more — plus, gathered a few highly rated options for you to shop.
What is onion shampoo?
Onion shampoo is exactly what it sounds like — shampoo that has onion as a main ingredient. Though it may sound funky, the experts we spoke to agree that onion extract can help hair health. “Onion contains sulfur, which is a key building block for keratin, the protein that makes up your hair,” says Dr. Ross Kopelman, a hair transplant surgeon at Kopelman Hair Restoration. “It also has antimicrobial properties that can support a healthier scalp environment. Some studies suggest it may increase blood flow to the scalp and reduce inflammation, which are both important for hair health.”
Most commonly, hair products with this vegetable are aimed at helping with hair thinning and encouraging growth. One clinical trial even found that when onion extract was applied topically, it helped people with alopecia areata (an autoimmune disorder that causes hair loss) with regrowth. “While we need more research, I’ve seen some patients benefit when using onion-based treatments as part of a broader hair care routine,” says Kopelman.
The perks may sound great, but worried that onion shampoo will leave you smelling like the deli counter? Don’t be. While onion extract may be a primary ingredient, the shampoos available that use it also have other beneficial (and pleasant-smelling) ingredients, such as lavender or rosemary.
Can anyone use onion shampoo?
In general, over-the-counter shampoos with onion extract are gentle and sulfate-free, so they should be safe for just about everyone to use. That said, if you have color-treated hair, you may want to think twice. “Onions are acidic, so using them on color-treated hair can disrupt the delicate PH balance needed to prolong the look of freshly colored hair,” says Chacon. “Avoiding the shaft of the treated hair and concentrating at the scalp is an option but be sure to patch test to ensure you don’t have any scalp sensitivity.”
Chacon also recommends that those with sensitive skin proceed with caution. “The smell could also be a hindrance here as well as the effect onions have on the eyes and the close proximity of the scalp to the eyes,” says Chacon. “Instead, I would opt for rosemary oil — which is an alternative natural ingredient that has all of the antifungal, growth promoting effects but with a pleasant scent.”
Finally, if you are allergic to anything in the allium family (like onions or garlic), it’s best to skip this type of shampoo. “I’ve seen a few cases of contact dermatitis from poorly formulated onion shampoos,” says Kopelman. “Also, if you have eczema or active scalp inflammation, it’s best to consult with a specialist before adding anything new to your regimen.”
5 onion shampoos to shop
Ready to jump on the bandwagon and try some onion shampoo? Our experts recommend using it once or twice a week to reap the full benefits. Any less and you may not notice any changes, any more and it may be too harsh. Below, we’ve rounded up some of the most popular onion shampoos available.
This gentle shampoo is arguably the most popular onion shampoo on TikTok. It has onion extract to accelerate hair growth, as well as peptides to help with elasticity and lavender extract to protect against breakage, according to the brand. The formula is also lightweight, so it won’t weigh down strands.
“I would truly never know or guess that there was onion in this shampoo if you didn’t tell me,” says NBC Select reporter Zoe Malin, who was sent a sample from the brand. “It smells like a professional-grade shampoo and the floral fragrance is pretty strong, but not bad at all. It’s a standard shampoo — lathers well, washes out easily and makes my hair and scalp feel clean.”
Onion extract is the star ingredient of this shampoo, but it also has plant keratin to strengthen and vitamin E to nourish the scalp, according to the brand. It’s also free of sulfates, silicones, parabens and mineral oils, making it a nice choice for those with sensitive skin. Mamaearth also makes an onion hair oil treatment to help with dehydrated hair. This shampoo has a 4-star average rating from 9,463 reviews on Amazon.
Part of the beauty retailer’s “Clean at Sephora” line, this shampoo is made with natural ingredients and is vegan and cruelty-free, according to the brand. In addition to encouraging hair growth, it has additional ingredients that also provide natural UV protection, according to Fable & Main. It also has a pleasant, spicy scent thanks to a mix of nutmeg, saffron and sandalwood.
This set comes with shampoo and a leave-in conditioning treatment — both of which have onion extract. While the experts we spoke with say you should only use onion shampoo a few times a week to avoid irritation, this set is gentle enough for daily use, according to the brand. It also has rosemary to strengthen hair and give it a herbaceous scent and biotin for shine. The set has a 4.2-star average rating from 5,073 reviews on Amazon.
If smelling like an onion is one of your primary concerns about this type of shampoo, consider this unscented formula. The gentle formula is safe for color-treated hair and has antioxidants to help strengthen hair, according to the brand. It has a 4.4-star average rating from 3,841 reviews on Amazon, with many reviewers saying their hair feels soft and noticeably stronger after using it.
Meet our experts
At NBC Select, we work with experts with specialized knowledge and authority based on relevant training and experience. We also ensure all expert advice and recommendations are made independently and without undisclosed financial conflicts of interest.
- Dr. Anna Chacon is a board-certified dermatologist in Miami, Florida.
- Dr. Ross Kopelman is a hair transplant surgeon at Kopelman Hair Restoration
Why trust NBC Select?
Bethany Heitman is a contributor at NBC Select and a journalist who regularly covers beauty, home and lifestyle. For this story, she interviewed two experts on the benefits of onion shampoo.
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