The 5 Best Oils For Hair Growth That You Need To Know About

Elle

24-06-2025

Oils have long been hailed as heroes for hair growth, but separating fact from fiction is no small feat. With roots in many ancient practices, such as Ayurvedic rituals, the relationship between long lengths and natural oils is nothing new. Rosemary oil has become a coveted essential extract in recent years, garnering mass appeal on platforms such as TikTok and making headlines for its controversial supposed benefits. The question is: do any of these extracts actually work, and what does the science say?
'People assume that massaging olive oil, sesame oil, sunflower oil, or rosemary oil into their scalps is beneficial because it moisturises the scalp (which it does) or potentially helps reduce inflammation and promote hair growth,' says Trichologist Mark Blake. However, he advises that he is generally against individuals oiling their scalps, particularly if they don't know exactly what they are using and why.
Here, expert trichologists and consultant dermatologists break down the essentials of oils for hair growth, how to use them in the safest possible way, and the alternative formulas for everyday use.
According to Consultant Dermatologist Dr Derrick Phillips, oils such as argan, castor, rosemary, lavender, and coconut oil do offer benefits such as moisturising the scalp, contributing overall scalp health, reducing inflammation, and supporting hair elasticity. However, he highlights that there are also a handful of risky downsides when these essential oils are used improperly. Think scalp build-up, irritation, greasiness and the exacerbation of existing scalp conditions.
'The main problem is that people don't remove these oils, and this can create its own set of problems,' explains Blake. 'The worst mistake is to leave oils on the scalp overnight as the product deteriorates overnight on your scalp and mixes with the yeast, bacteria and fungus that is already on your scalp, as well as parasites such as demodex.'
Don't be alarmed by this news. These tiny, microscopic mites live on everyone, in the hair follicle. 'They are so small (0.15mm – 0.4mm) that it would take around 10 of them to cover a pin head,' he says. 'Demodex feast on excess oil and skin cells, increasing the overall microbial load on your scalp. In some cases, leaving oils on your scalp might create more itching, dryness and irritation than you already had.'
While there is some scientific research into the benefits of essential oils for hair growth, it's important to weigh these benefits against the risks. Many experts recommend diluting potent oils, such as rosemary and peppermint, with carrier oils like argan and coconut to prevent irritation.
What experts agree on is that pure oil should not be left on the scalp, particularly overnight. Instead, the safest option is to use professional formulas containing these famous extracts, rather than relying on at-home concoctions and guesswork.
Argan oil is a natural oil derived from the kernels of the fruit of the argan tree, and is popularly used in skin and hair care formulas.
'Argan oil is rich in vitamin E and fatty acids, which work to hydrate the scalp and hair,' explains Phillips. 'Research suggests that it can be beneficial in protecting hair against oxidative damage. It also has anti-inflammatory properties that can help soothe a dry, flaky scalp and alleviate conditions such as dandruff, promoting overall scalp health. The antioxidants and fatty acids in argan oil can also improve the elasticity of hair, making it less prone to breakage. While it doesn't directly stimulate hair growth, its rich properties support better hair health, which can indirectly benefit hair growth.'
He explains that applying pure oils, such as argan oil, directly to the scalp can exacerbate conditions like dandruff and blocked pores. As with any oils, excessive application can also lead to greasy hair. It's also important to note that, although argan oil is derived from the fruit of the argan tree (which is a type of tree nut), it's always best to exercise caution if you have an allergy.
In short, castor oil is a vegetable oil derived from the seeds of the castor bean plant. While it's less luxurious than the aforementioned argan oil, it boasts a number of similar moisturising benefits.
'Castor oil is composed of ricinoleic acid, a fatty acid known for its anti-inflammatory benefits,' says Phillips. 'It also contains omega-6 fatty acids and vitamin E, both of which are beneficial for scalp and hair health. Its natural humectant properties help the scalp and hair retain moisture, guarding against breakage and creating an environment more favourable for hair growth. Castor oil is also believed to have anti-bacterial and anti-fungal properties, which support a healthy scalp and help reduce irritation.'
When it comes to the drawbacks of castor oil, he explains that the thick, sticky consistency of castor oil can make it difficult to apply and remove. As a result, it can cause a build-up on the scalp potentially exacerbating conditions such as dandruff.
As you can probably guess, lavender oil is distilled from the lavender plant. As well as being a hero when it comes to aromatherapeutic benefits, it also offers some perks for hair growth.
'While animal studies have found that lavender oil can help to thicken hair, stimulate growth, and accelerate growth rate, human studies are relatively limited,' warns Phillips. 'What we do know about lavender oil is that it has antimicrobial and anti-inflammatory properties which can support a healthy scalp, something that is vital for hair growth.'
However, an excess of lavender oil can irritate the skin. 'Always do a patch test and ensure it's diluted before applying topically,' he says.
As with many of the mentioned oils, peppermint oil has been linked to hair growth due to its ability to stimulate blood flow to the scalp, but should never be used alone directly on the scalp. Research suggests that it also possesses some antimicrobial and anti-inflammatory properties.
'My suggestion is to look for shampoos containing ingredients like peppermint oil (such as Nioxin Scalp and Hair Shampoo),' says Blake. 'Peppermint oil increases blood flow to the scalp, giving your hair follicles a much-needed rush of blood and nourishment, and it is easy to use.'
He also adds that shampooing frequently is beneficial for the scalp. 'You should treat your scalp like any other part of the body. As a trichologist, I see more problems in patients who don't wash their hair frequently than in those who do.'
Arguably the most famous of the essential oils for hair growth, rosemary oil has gained a viral fanbase for its alleged ability to grow longer lengths.
'Rosemary oil is thought to improve scalp circulation and reduce inflammation around hair follicles,' explains Phillips. 'One study found that rosemary oil was as effective as Minoxidil in treating androgenetic alopecia however, it was compared to 2% Minoxidil instead of the 5% solution that is commonly recommended for hair loss.'
While there is some evidence that rosemary oil contributes to new hair growth, rosemary water can offer a slightly reduced risk of irritation. 'Potential drawbacks of rosemary oil include the fact that there is a risk of skin irritation if not diluted properly and also it's not a quick fix and requires consistent use in order to see results.'
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Katie Withington (she/her) is the Beauty Writer, at ELLE UK and Harper's Bazaar. Working alongside the ELLE UK Beauty Team, she covers all things beauty for both print and digital, from finding backstage make-up trends at London Fashion Week and investigating buzzy skincare ingredients, to unzipping the beauty bags of Hailey Bieber and Margot Robbie. Prior to joining ELLE UK in 2022, Katie studied (BA) Fashion Journalism at London College of Fashion and has previously contributed to Red, Good Housekeeping and Prima.