7 Ingredients Worth Including In Your Haircare Routine

“Essential oils are full of healthy fats for nutrition, and some work double time to nourish and moisturise your hair while also being excellent for hair growth, strength and elasticity. Castor oil – derived from the castor bean plant – is an emollient that smooths the outer cuticle to lock in shine. It’s best used in treatment-based products, so you’ll often find them in pre-shampoo or deep-conditioning treatments. To use castor oil on its own, apply it to damp hair so it can effectively penetrate the follicle. Afterwards, shampoo it out and follow up with a conditioner to ensure any residue is washed away. Alternatively, you can use a shower cap or microfibre towel after applying the oil to trap the heat and create a steam which will enable better absorption of the product. If you have fine hair, always double cleanse and avoid applying it directly to the scalp as this can make hair limp and oily at the roots, and provide a breeding ground for dandruff. Expect instant results after the first use but cumulative effects will include resistance to breakage and stronger, longer hair.” – Anabel Kingsley, brand president & trichologist at Philip Kingsley

“By now you’re likely to have seen rosemary oil all over TikTok. It has anti-inflammatory properties which improve scalp blood circulation and healthy growth. Typically, minoxidil has been an active ingredient recommended by professional trichologists to combat hair loss and, while it’s proven to be effective, rosemary oil has stepped up to the plate in clinical studies. Part of this is related to the way it moisturises the scalp to reduce dryness and itchiness too. While also preventing hair loss, it maintains thicker, longer hair when used regularly. The best way to use it is to mix in a couple drops with another oil, such as coconut or jojoba, massage it directly into the scalp, leave it on for 20 minutes, then shampoo the oils out. Those with thinner hair will also benefit from adding this to their routine once a week. You can also blend it into shampoo or opt for products that contain rosemary oil or leaf.” – Hollie

“We all know how great this ingredient is for the skin, so it's no wonder it does great things for hair too. Locking in moisture to banish frizz, it also protects hair from environmental pollution – just like it does for the skin barrier. While there aren't many dedicated hair-based hyaluronic acid treatments, some brands have started including it. I’d recommend The INKEY list’s Hyaluronic Acid Hydrating Hair Treatment, which can be used post-wash like a leave-in conditioner.” – Hollie

“One of the better-known haircare ingredients, keratin smooths hair cells to give strands a more manageable feel. This is especially useful when the hair is drying – making for a far glossier, healthy look. You’ll often find keratin in at-home treatments, serums and conditioners. I’d try Virtue Labs and treatments like 72hair. You can also get a professional keratin treatment in most major salons, where a high potency of keratin is applied to the strands to seal the cuticle for silkier, frizz-free hair.” – Hollie

“Protein is essential for maintaining strong and healthy hair. Treating all types of damage, from colour to heat and chemical treatments, it strengthens weak hair and builds resilience. Opt for products that contain proteins such as keratin, wheat protein or panthenol. Panthenol helps seal off the cuticle for smoother hair and can prevent frizz and split ends.” – Hollie 

“Pea protein – which we use within our Liquid Hairbrush Conditioner – is an ingredient worth adding to your routine. It works by flooding the scalp with moisture to improve firmness and elasticity, leading to stronger, more resilient hair. Along with these moisture-boosting benefits, pea protein has additional anti-irritancy properties ideal to combat dryness and itchiness on the scalp.” – Hair Stylist Larry King 

“Most commonly found in scalp exfoliators, glycolic acid promotes a healthy microbiome and removes build-up by balancing the natural oils and supporting the hair follicles. It can be found in treatments like The INKEY List’s Glycolic Acid Scalp Treatment, which not only gently exfoliates the skin, but also regulates irregularities and congestion. Simply apply it to wet or dry hair pre-shampoo and leave on for ten minutes before washing out.” – Hollie