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16 best hair growth serums that actually work for thicker-looking hair 2026 – tried and tested
Like my hair? Gee, thanks, I grew it myself
Testing the best hair growth serums has always been one of my favourite parts of my job as Cosmopolitan UK’s Beauty Ecommerce Writer.
Recently, after removing my hair extensions following four years of wear, I’ve found myself more focused than ever on finding serums that genuinely deliver results — think thicker-looking hair, a healthier scalp environment and, with consistency, improved growth.
Best hair growth serums, tried and tested 2026
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Do hair growth serums actually work?
The big question: do hair growth serums actually work? The key thing to remember is that, sadly, a bottle of this stuff won’t make your hair regrow overnight. But the best serum can help get hair loss under control, give the illusion of a thicker, fuller mane and add a bit of length (if you stay consistent, that is).
Dr Sharon Wong, Consultant Dermatologist and Hair Specialist, explains that “many hair growth serums contain peptides/amino acids and conditioning agents such as hyaluronic acid. These have an aesthetic effect on the hair that’s already on your head, giving it more volume and plumping up its fibres to make them seem thicker and denser.” Many also feature a type of DHT blocker. DHT is an androgen that can cause hair loss to happen at a faster rate, so certain ingredients (and natural ingredients like pumpkin seed oil) can block DHT and prevent hair follicles from shrinking.
Above all, Dr Sonia Khorana, Dermatologist and Aesthetic Doctor, says that consistency is key: “For hair thinning, visible changes take time. Initial growth may appear as fine, thin hairs, gradually thickening over 3–6 months, while full regrowth can take up to a year,” she says.
It’s important to remember that healthy hair growth starts from the inside, and a bottle of hair serum will unlikely deliver noticeable results alone. Maintaining a healthy diet, as well as reducing stress levels, is by far the best way to ensure a healthy and strong hair growth cycle.
Hair serums vs hair oils: Which is better?
While both serums and oils can help your hair growth journey, they work in very different ways to each other. A hair growth serum is often water-based, making it a very lightweight tonic to apply to your roots. Often formulated with ingredients like peptides, biotin, minoxidil and caffeine, they’re specifically made to prevent shedding or stimulate growth.
A hair oil, on the other hand, is much richer in consistency, and is usually made from an argan, coconut, rosemary or castor seed base. Hair oiling has become a very popular practice, though rooted in over 3,000 years of South Asian heritage, and is used to nourish the scalp, creating a healthy environment for fortified hair growth.
It’s important to remember that while shedding is normal (we shed around 80-100 hairs per day) you should speak to a GP or a trichologist if hair thinning becomes a bigger concern.
UKHair Hair Growth Serum
UKHair Hair Growth Serum
Pros
- Testing saw that 85% of users saw visible hair regrowth after three months
- A good option for those with fine hair
Cons
- As hair growth has a longer growth cycle than eyelashes, expect results to take longer compared to UKLash eyelash serum
If you're a fan of UKLash's Eyelash Growth Serum, you'll know that the brand is an expert when it comes to hair growth. And trust me, the results are there to prove it.
The UKHair Growth Serum contains AnaGain™ (pea sprout extract), turmeric, and lemon fruit extract that not only stimulates the hair follicles to encourage growth, but also nourishes the scalp to minimise hair loss.
I also love that the serum has a water-weight texture to it, so it seamlessly sinks into the scalp without leaving a greasy residue.
Customer review: "I’ve tried everything – gummies, rosemary oil, different shampoos, brushes, not washing as much. I had thin hair before my pregnancy but even worse after. Now here I am after three months of using the serum every other day and my hair is so healthy, thick and shiny. I love it and can’t wait to see what it’ll look like in a years time."
Key Specifications:
| Key Ingredients: | AnaGain (pea sprout extract), turmeric and lemon fruit extract |
|---|---|
| Who’s it best for? | Everyone |
| Results timeline: | The brand suggests using the serum for 12-18 weeks |
| Texture: | Lightweight, non-greasy serum |
Hello Klean Full Control Anti-Thinning Scalp Serum
Hello Klean Full Control Anti-Thinning Scalp Serum
Pros
- Clinical trials saw 25% less hair shedding in 56 days
- Formulated without SLS, SLES, parabens and silicones
- It’s a very decent price for a hair loss serum
- It’s not sticky or heavy
Cons
- It only contains 30 ml of product
Did you know your scalp is most vulnerable right after you wash it? Yep, after getting out the shower the warm water can cause sensitivity, which increases transepidermal water loss, and your scalp barrier is temporarily thinner.
The Hello Klean Full Control Anti-Thinning Scalp Serum is designed for this moment of vulnerability where your scalp needs a little extra love.
Formulated with peptide growth factors, zinc chloride and green tea, the leave-on serum is designed to “reduce hair loss by 37.5% after 84 days.” Hows it done? “Each of these ingredients help support scalp and follicle health in different ways. Peptide growth factors act like messengers, stimulating cell repair and signalling pathways that support stronger hair growth. Green tea is rich in antioxidants and can reduce inflammation, while zinc chloride can help regulate oil production and has antimicrobial properties, keeping the scalp balanced,” explains Dr Sonia.
Customer review: “The hair by my temples started thinning over the past year due to constantly slick-bun styling but I've been using this serum continuously for the past 2 months and it's be growing back fuller ever since!”
Key Specifications:
| Key Ingredients: | Peptide growth factors, zinc chloride and green tea |
|---|---|
| Who’s it best for? | Designed for hard water-triggered thinning – so anyone living in a hard water area |
| Results timeline: | Hello Klean clinical trials found that after 84 days, participants saw a 37.5% reduction in hair shedding |
| Texture: | Lightweight serum |
L'Oreal Paris Elvive Growth Booster Scalp Serum
L'Oreal Paris Elvive Growth Booster Scalp Serum
Pros
- It's an affordable option
- It keeps the condition of the scalp healthy to encourage growth
- It contains Aminexil, an ingredient used to prevent hair fall
Cons
- The results are more subtle than others in this edit
If hair loss is your main concern – oh, and keeping to a reasonable budget – give the L'Oreal Growth Booster Scalp Serum a try. No, it won’t magically grow you luscious locks after three weeks (tbh, no product is a miracle; growth takes time), but it will keep your scalp moisturised and in healthy condition – encouraging new hairs will thrive. Plus, with a stronger scalp that’s less congested with build-up, you’ll see less hair fall resulting in thicker, denser hair.
The best way to use this is on clean, damp hair. Squeeze a few drops around your scalp and use a massaging brush to work it in. There’s no need to rinse but will feel completely undetectable once your strands are dry. Bish, bash and bosh.
Customer review: “Only been using this for weeks but already I have seen less hair loss. It smells amazing and leaves my hair so soft. Will definitely purchase again.”
Key Specifications:
| Key Ingredients: | Aminexil (to prevent hair fall), niacinamide and ginger extract |
|---|---|
| Who's it best for? | Hair loss, hair thinning |
| Results timeline: | Brand clinical studies found 78% reduction in hair loss after six weeks |
| Texture: | Serum |
The Inkey List Salicylic Acid Exfoliating Scalp Treatment
The Inkey List Salicylic Acid Exfoliating Scalp Treatment
Pros
- Lightweight and water-based formula that quickly absorbs
- Affordable
- Stimulates hair follicles to encourage growth
Cons
- Less effective for hair loss
Products promising to grow you a new head of hair don't come cheap, but this one's £15 and it works.
It contains invigorating caffeine extract, which aims to help to improve hair thickness and density. Thanks to its anti-fallout and anti-dandruff powers, this will help give hair a full reset. It even works for colour-treated strands, so you can enjoy more dazzling vibrancy.
Customer review: "I have repurchased this 3, maybe 4 times so far. It feels like it is working, I like the applicator and the coolness when you put it on your scalp. I've been using this alongside rosemary oil, so I don't know if it is either or the combination that works, but it does work!"
Key Specifications:
| Key Ingredients: | Caffeine powder, Redensyl (to encourage growth) |
|---|---|
| Who’s it best for: | Thinning hair, sensitive scalps, everyone |
| Results timeline: | The brand suggests using the serum for a minimum of three weeks |
| Texture: | Lightweight serum |
Pros
- Revitalises scalp to encourage growth and thicker hair
- Boosts hair softness and shine
Cons
- May be too rich for oily scalps
- Needs to be used as a pre-wash treatment – less convenient
While technically a hair oil as opposed to a serum, Hair Syrup's Rapunzel still does wonders in promoting healthy and strong growth. The oil is formulated with grapefruit and flaxseed, both known as natural ways to boost growth and moisture.
To use, squeeze a few drops over your scalp and use a massage brush to work the product in – the nourishing oils will feed your scalp, promoting a healthy environment for hair to grow. You can also add it to your mid-lengths to bring life back to broken, brittle strands.
Customer review: "I will repurchase this over and over again. It smells amazing and it does exactly what it says it will. It has made my hair thicker and healthier and has helped it to grow."
Key Specifications:
| Key Ingredients: | Pink grapefruit, flaxseed, castor seed and pomegranate |
|---|---|
| Who's it best for? | Dry scalps, brittle lengths, hair growth |
| Results timeline: | The brand suggests using the oil for three months to see results |
| Texture: | Oil |
Nanogen Hair Growth Factor Treatment Serum
Nanogen Hair Growth Factor Treatment Serum
Pros
- It’s non-oily and feels hydrating on the scalp
- Dermatologist tested and suitable for sensitive scalps
- It’s affordable
- It has a fresh, citrus-like aroma to it
Cons
- As it works on the hair growth cycle, you may not notice results for two to three months
While the term “hair growth” is somewhat of a buzz word with over two million TikTok hashtags, but to Nanogen, its Hair Growth Factor Treatment Serum is the result of over 20 years of research.
This super potent yet gentle serum (yep, it’s sensitive-scalp approved) is clinically proven to stimulate hair cell production, extend the hair growth cycle and revitalise hair follicles – thanks to a stellar concoction of peptides, pea sprout extract and redensyl. To use, simply distribute one pipette-full over your scalp and use a massage brush to work it in. The serum is incredibly lightweight so it feeds your scalp without feeling sticky or heavy. Stay loyal and you’ll notice visible results, like a thicker hair line and reduced shedding.
Glowing customer review: “It works! I use it every day and after a while my fine, thin hair has thickened.”
Key Specifications:
| Key Ingredients: | Peptides, pea sprout extract, redensyl, botanical actives |
|---|---|
| Who’s it best for: | Those with dry scalps |
| Results timeline: | The brand suggests using the serum for 12 weeks to notice results |
| Texture: | Serum |
Philip Kingsley Density Preserving Scalp Drops
Philip Kingsley Density Preserving Scalp Drops
Pros
- A very lightweight formula that doesn’t leave any sticky residue
- Improves hair density and prevents hair fall
Cons
- It’s a little expensive – although you get 85ml of product
I never quite believed it until I was experiencing it for myself, but major stress really can cause your hair to fall out. A few months ago I started to notice more hair loss when showering. What once used to be a few strands coming out with my shampoo, now seemed like major loss – and it was freaking me out.
Needing a fix immediately, I started using the Philip Kingsley Density Preserving Scalp Drops every day, applying onto damp or dry hair – luckily, it’s a super lightweight serum so it doesn’t cause any stickiness. After just a few weeks of consistent use, I saw far less strands falling out in the shower and overall my hair line seemed much thicker.
It’s not just a miracle, it’s thanks to caffeine, a peptide blend and azelaic acid which help to stimulate hair growth, prevent hair fall and reduce oiliness.
Glowing customer review: “I love this brand, hands down. This particular line in the brand really brought my hair back to health. I love the drops and still use them now and then to keep my scalp in good order.”
Key Specifications:
| Key Ingredients: | Caffeine, peptide blend and azelaic acid |
|---|---|
| Who’s it best for? | Anyone noticing increased hair fall in the shower |
| Results timeline: | The brand suggests using daily for three months to first see results |
| Texture: | Serum |
Vichy Dercos Anti-Hair Loss Aminixel Clinical Regen Serum
Vichy Dercos Anti-Hair Loss Aminixel Clinical Regen Serum
Pros
- It’s very lightweight, non-sticky and doesn’t stain
- Helps roots appear fuller and more volumised
- Contains the perfect concoction of ingredients to support growth
Cons
- You have to apply five pipette-fulls, which feels like quite a lot
When a hair serum promises to grow +14,000 new hair in 12 weeks, it has my attention. Launching in September last year, the Vichy Hair Renewing Serum has garnered quite the buzz amongst editors for its clinically proven ability to stop hair loss, stimulate the follicle cycle and improve hair density, all thanks to a show-stopping formula of 5% Aminexil, 3% niacinamide and ginger root extract – i.e., the ultimate trifecta of ingredients to promote hair growth.
Aminexil, derived from minoxidil, slows down hair loss by targeting the collagen around hair follicles, preventing it from hardening. This also prolongs the hair growth phase. Then you’ve got niacinamide and ginger root extract which balance the scalp microbiome and prevent inflammation. The result? You lengths will feel stronger, denser and healthier in a few months.
And because these factors are important too, you’ll be pleased to know the serum is so lightweight – it almost feels like water – and easily absorbs without leaving any residue.
Glowing customer review: “I use this serum every day and it feels very pleasant and refreshing on my scalp. It also smells great. I’m not experiencing hair loss and my hair is growing back.”
Key Specifications:
| Key Ingredients: | Aminexil, niacinamide and ginger root extract |
|---|---|
| Who’s it best for? | Anyone and everyone |
| Results timeline: | The brand recommends using the serum daily for three months |
| Texture: | Serum |
Sweed The Hair Serum
Sweed The Hair Serum
Thinning around the hair line (also known as a receding hair line) is most common in men, but this isn’t to say women aren’t effected too. While it’s less prevalent, women can still experience a thinning hair line, with underlying causes like genetics or hormone imbalances causing the shedding.
If you’ve noticed this in in your own hair – it’s easier to tell when you have your hair in a pony tail – the Sweed Hair Serum is a wise investment for you. Cleverly, the rollerball design means you can focus the serum directly onto your hair line, and the lightweight, non-oily formula quickly absorbs into the scalp without leaving a greasy residue.
The ingredients list is impressive too, with actives like biotin, peptides, keratin and pumpkin seed extract working to stimulate growth. Apply the serum every day, morning or night, and you’ll slowly start to see results.
Customer review: “I can’t believe how wonderful this product is: effective and fast working. I have baby hairs coming in!!! So grateful for this product. I bought it for my sister also.”
Key Specifications:
| Key Ingredients: | Peptides, keratin, biotin, hyaluronic acid, panthenol |
|---|---|
| Who’s it best for? | Those with a thinning hair line |
| Results timeline: | The brand suggests using for six weeks to notice first results |
| Texture: | Serum |
Kama Ayurveda Bringaras Invigorating Scalp & Hair Oil
Kama Ayurveda Bringaras Invigorating Scalp & Hair Oil
Kama Ayurveda’s Invigorating Scalp & Hair Oil is more than a hair-growth serum – it’s a ritual in itself. Designed as a pre-shampoo treatment, it should be left on the scalp for around 20 minutes before rinsing. The rich botanical blend brings together 13 plant extracts to help soothe and hydrate an irritated scalp, support healthy growth, and provide antioxidant protection.
Massage a few drops into the scalp using your fingertips or a scalp brush, but I’d also recommend working it through the lengths. Instantly, strands feel softer and look glossier, and with regular use my scalp felt calmer and healthier. The aroma is beautifully grounding too – rather than rushing the application, take a moment to breathe it in as you work it through. It feels like bringing a spa experience into your own bathroom.
Glowing customer review: “Amazing results with this oil: after first use, my hair felt much lighter and my scalp was not itching anymore. After a few uses, I noticed more volume and fuller hair. I will definitely keep on using this product at least once per week.”
Key Specifications:
| Key Ingredients: | 13 botanical extracts, including Balloon Vine (anit-oxidant), False Daisy (stimulates growth) and Indigo (soothes) |
|---|---|
| Who is it best for? | Those with dry, irritated scalps |
| Texture: | Oil |
Hair + Me The Drops
Hair + Me The Drops
Pros
- Minoxidil is clinically proven to boost hair growth with consistent use
- This is a personalised treatment, delivered to your door, that is supplied by a dermatologist
Cons
- Some users may experience an initial shedding phase before growth starts
The sister brand to Skin + Me, Hair + Me is the first online hair growth subscription service that prescribes you with a daily-use serum or capsule, delivered to your door every month.
Whether you choose the serum or capsule, both treatments are formulated with minoxidil – a clinically tested, active medication that increases blood flow to hair follicles, helping re-growth. The drops also include supporting ingredients, like lactic acid and essential oils, to maintain a healthy and hydrated scalp.
All you’re instructed to do is take/apply the capsule or serum daily, and over a period of four months (with full results seen at six months) you’ll notice thicker and fuller hair. You can read the Cosmo review here where Meg, Cosmo's Video Lead, tested out the service.
Customer review: “I’ve seen a significant transformation, my hair is thicker and more dense. I've noticed LOTS of new baby hairs and my hair feels silkier and healthier.”
Key Specifications:
| Key Ingredients: | Minoxidil, lactic acid and essential oils |
|---|---|
| Who's it best for? | Hair loss, hair thickening |
| Results timeline: | Six months for a full treatment |
| Texture: | Serum or tablets |
Chāmpo Pitta Growth Serum
Pros
- Backed by clinical evidence to show noticeable results in 12 weeks
- It has an aromatherapy-like aroma
Cons
- It promises to encourage growth but isn't a medical-grade treatment like minoxidil
A rare few products generate universal buzz amongst beauty experts and editors – Chāmpo's Pitta Growth Serum is one of them.
The formula contains caffeine, peptides and DHT-blocking red clover extract, making it the perfect trifecta for stimulating hair growth. Cleverly, the serum targets a hair-loss hormone named DHT. By managing its levels, the tonic significantly prevents hair loss while also stimulating new growth.
Customer review: "I never leave reviews but felt I had to for this product. I've been using this serum daily for around 2 weeks and already seeing a difference. I'm noticing less hair shedding, my hair appears fuller and shinier and I'm noticing new hair growth in problem areas. I'm delighted and very surprised by how quickly I've noticed a difference- other people have also commented on the difference in my overall hair health."
Key Specifications:
| Key ingredients: | Caffeine, peptides and DHT-blocking red clover extract |
|---|---|
| Who's it best for? | Hair growth and fall out |
| Results timeline: | Clinical trails found that after 12 weeks, 90% experienced less hair loss |
| Texture: | Serum |
The Ordinary Multi-Peptide Serum For Hair Density
The Ordinary Multi-Peptide Serum For Hair Density
Pros
- It's a budget friendly option
- It contains an impressive list of ingredients to boost density
Cons
- Too much product can feel a little sticky
So many of us on the Cosmo beauty team love this budget option, and it’s thanks to the protein-building amino acids which helps to strengthen and repair damaged strands, while procapil, redensyl, and baicapil increase blood flow in the scalp, working to promote thicker and denser hair.
Not only that, but the concentrated formula also contains caffeine to improve hair density. So while this may only be a budget bottle, I can assure you that after consistent use, you will start to see noticeable results.
Glowing customer review: “The Ordinary Multi-Peptide Serum for Hair Density is amazing! After a few weeks, my hair feels thicker, fuller, and healthier. It absorbs easily without feeling greasy and makes my scalp feel refreshed. For the price, it’s a great deal and really works if used consistently. Highly recommend!”
Key Specifications:
| Key Ingredients: | Amino acids, procapil, redensyl, baicapil and caffeine |
|---|---|
| Who's it best for? | Those with thin hair, on a budget |
| Results timeline: | The brand suggests using for 12 weeks |
| Texture: | Lightweight serum |
Kérastase Genesis Serum Anti-Chute Fortifiant
Kérastase Genesis Serum Anti-Chute Fortifiant
Pros
- Contains aminexil, ginger root extract and caffeine to boost hair follicles and prevent breakage
- Supports and nourishes the scalp
- Easy application with pipette
Cons
- Requires roughly four drops per day, meaning the bottle can be used up quickly
Your hair is never going to look or feel good if your scalp isn't on point. This formula delivers some much-needed hydration to roots, helping to eliminate dandruff.
Containing energising ginger root and Aminexil (L'Oreal's big dog in the hair loss treatment game), the lightweight serum left me with healthier heads of hair and fewer breakages. Locks were left shinier and smoother, too.
If you're struggling with baby hairs' that refuse to grow past a certain point, add this one to your basket ASAP.
Customer review: "Lord!!! wonderful product, I have used many other companies against hair loss, this one is number 1, smells so nice and gentle. This is my 2nd bottle results after two weeks. Thank you Kerastase!!!The most important thing is that the shine of the hair is not lost after application."
Key Specifications:
| Key Ingredients: | Ginger root and Aminexil (to prevent hair loss) |
|---|---|
| Who's it best for? | Dandruff and dry scalps |
| Results timeline: | Use daily to see results after six weeks |
| Texture: | Serum |
Monpure Follicle Boost Hair Density Serum
Pros
- It contains pumpkin seed extract which blocks DHT – an androgen that is associated with hair loss in the body
- Supports the condition of the hair and scalp to boost shine and reduce breakages
Cons
- It's an expensive formula
- It helps to boost hair density, but is not a guaranteed hair growth serum
If you ever suspected that vegan products weren't as powerful as their animal-derived counterparts, this serum will prove you wrong.
Expect to see healthier, smoother, more hydrated ends, with a big drop in split ends, too. Some injected volume could also be spotted at the roots, while strands were seen with some diamond-like shine. Prepare to be seriously impressed.
Customer review: "I have been experiencing a lot of hair loss. My hair was looking and feeling thinner, and I was feeling self conscious. I tried soooo many other oils and nothing changed. I gave this one a try and OMG. The week after I started using it, I could count the hairs in my brush with one hand. After two + weeks, my scalp has been feeling less tender to the touch, and I can even see my scalp slowly starting to cover with hair again! It is a little more pricey, but if you buy anything hair oil, it is a waste of your money. But this one instead!"
Key Specifications:
| Key Ingredients: | Retinol, pumpkin seed extract, rosemary oil |
|---|---|
| Who's it best for? | Hair growth, hair loss, hair thinning |
| Results timeline: | The brand suggests using for six months to see the maximum results |
| Texture: | Serum |
Fable & Mane HoliRoots Hair Oil
Pros
- Helps boost scalp health and hair condition
- Has an aromatherapy scent of jasmine sambac, champaca, cedarwood and tonka beans
Cons
- The formula may be too rich for those with fine strands
- Some may not like the aroma
Never used a pre-wash treatment? 1) Where have you been?! 2) It's dead easy and will leave you with healthier hair in no time. This did just that, thanks to its oil-rich formula including safflower, sesame, castor and jojoba, to name but a handful of goodies.
Not only does it leave hair smelling divine thanks to its nose-pleasing scent, but it also improves thickness and works to banish dandruff. Prepare to see hair looking revived and healthier, with dry scalps quenched.
Customer review: "As a nurse in New York my hair is consistently getting damaged by washing it before and after work. Either from overwashing or the stress, I noticed my hair getting weaker and thin. Since I started using this in my hair routine, my hair feels fuller. The scent is very calming. I would absolutely recommend this product to individuals who work in a field where they put a lot of stress on their hair."
Key Specifications:
| Key Ingredients: | Safflower, sesame, castor and jojoba oils |
|---|---|
| Who's it best for? | All, but best on curly, coily and wavy hair |
| Results timeline: | The brand says you may notice subtle results after two weeks, though consistent use is required to see further benefits |
| Texture: | Oil |
What causes hair loss?
No matter your age, ethnicity or gender, hair loss can plague us all. So, how do you determine what's going wrong?
First up is intermittent shedding, aka going through phases of seeing more hair in your drains. “Seasonal hair shedding is a perfect example,” says Dr Wong. “Some people’s hair follicles are sensitive to changes to the number of daylight hours, leading to shedding that will self-limit without any treatment.
“Intermittent shedding can also be due to stress, dietary changes, periods of time when sex hormones are in flux – such as when starting, changing or stopping hormonal contraceptives or hormone replacement therapy (HRT), or after pregnancy – and following illnesses accompanied by a fever.”
There's also the stuff that can be trickier to treat:
- Genetic hair loss: Such as male or female pattern hair loss.
- Telogen effluvium: Sounds like a Harry Potter spell, but actually means excess hair shedding.
- Alopecia areata: This autoimmune hair loss condition may affect a single patch of skin, but it can also take over multiple areas across the body, scalp and face.
- Traction alopecia: Hair loss due to excessive pulling from tight hairstyles (that slicked-back ponytail look ain’t worth it if you ask us).
If you notice inflammation, spots or sores around the area of hair loss, Dr Wong advises making an appointment with your GP. They can arrange a blood test to find out what's going on and give you a prescription if necessary.
How long do hair growth serums take to work?
Here’s the thing: a hair growth serum won’t magically grow you long, thick hair. There are so many factors that can contribute to healthy hair growth, including your diet, genetics and lifestyle. If anything, hair growth serums can encourage new baby hairs to sprout around your hair line. They will also promote a healthy scalp environment for your follicles to flourish.
Typically, hair growth serums take two or three months to notice subtle results; this could be a more hydrated scalp or a reduction in overall shedding. By the time you spot more noticeable results, like thicker and fuller hair, you’re looking at a time frame of around four to six months – with consistent use, that is.
Results will also vary depending on the formula; this is certainly not a one-size-fits-all treatment. Serums that contain ingredients like peptides and caffeine typically take longer to see results, and you may only notice small baby hairs peeping through. On the other hand minoxidil (seen in Hair & Me), is a clinically-proven topical ingredient for hair loss that’s backed by more robust studies. While, initially, the ingredient may cause temporary shedding, you should notice genuine results after three months.
And do hair growth serums actually work for hair growth?
Essentially, hair serums help create a healthier scalp environment, which is crucial for supporting stronger, thicker-looking hair over time. Some formulas are designed to soothe irritation, reduce dryness and support the scalp barrier — all factors that can contribute to shedding if left unchecked.
“Consistency is absolutely critical when treating thinning hair because it involves biological processes that take weeks to months to show measurable changes,” explains Dr Sonia Khorana.
That said, it’s important to manage expectations – you’re not going to grow Rapunzel-like lengths after a few weeks. “Visible changes take time. Initial growth may appear as fine, thin hairs that gradually thicken over three to six months, while more significant regrowth can take up to a year. Often, the first sign of success is stabilisation rather than dramatic regrowth,” adds Dr Khorana.
What are the best ingredients to look out for in a scalp serum?
Best hair growth serum ingredients, cheat sheet:
- Peptides: Best for supporting hair follicles
- Rosemary Extract: Best for supporting scalp health
- Niacinamide: Best for strengthening the skin barrier
- Caffeine: Best for stimulating hair follicles
- Biotin: Best for supporting keratin production (essential for healthy growth)
- Minoxidil: Best for prolonging the hair growth phase
- Green Tea: Best for reducing inflammation
According to Dr Sonia Khorana, there are several ingredients worth looking out for when choosing a serum to support scalp health.
“Peptide growth factors act as signalling molecules that help support cell repair and biological pathways associated with healthy hair growth. Green tea is rich in antioxidants and may help reduce inflammation, while zinc compounds can help regulate sebum production and provide antimicrobial support to maintain a balanced scalp environment,” she explains.
Rosemary extract and niacinamide are also commonly found in scalp serums because they support overall scalp health – niacinamide in particular helps strengthen the skin barrier and improve moisture retention.
You may also see caffeine included in hair growth serums which stimulates hair follicles. Biotin is another popular ingredient, as it supports keratin production, which is a key structural component of hair that contributes to strength and smoothness.
Another standout ingredient to look out for is minoxidil – one of the most studied topical treatments for hair thinning. It is believed to help prolong the hair growth phase and support follicle activity. In recent years, access to lower-strength, over-the-counter formulations has widened, making minoxidil-based serums easier to buy.
Clare Stephenson is the Senior Fashion and Beauty E-commerce Writer for Cosmopolitan, ELLE and Harper’s Bazaar. She has been an e-commerce writer since 2022, creating matter-of-fact reviews and shopping pages filled with her favourite products for every budget and need – whether that’s a glow-giving foundation, a high-tech LED face mask or the perfect wear-with-everything blazer.
Alongside writing, Clare loves to be in front of the camera creating shopping content, putting viral products to the test to see which ones are truly worth the hype. Through her work, she has interviewed leading dermatologists, makeup artists and industry experts to bring readers trusted advice and product recommendations.
Clare has contributed to titles across the Hearst UK portfolio, including Women’s Health, Good Housekeeping, Red and Prima. Prior to joining Hearst, she earned a BA in Multimedia Journalism from Bournemouth University, focusing her studies on magazines and editorial. She later worked as an editorial assistant at Voir Fashion Magazine, covering events including Fashion Week and interviewing notable brand founders.
Outside of work? You can find Clare strolling through London’s Columbia Road Market, pouring her fourth coffee of the day or heading to a Pilates class.
Follow Clare on Instagram @clarefrancesstephenson.
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