Lash serums: How they work, how to use them and the best lash serum to buy now

From mascaras that promise to plump and thicken to lash extensions, the quest for perfect lashes is one that most of us will spend our whole lives pursuing.

But just like the hair on our heads, our lashes need looking after too, so when we’re neglecting them, it’s no surprise that they end up prone to breakage and stubbornly resistant to curling.

best lash serum
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The A-list secret? Lash serum – and lots of it. It’s a back-to-basics approach that’s applied before any other enhancements, and really can make all the difference. Used once a day, a good lash serum will support and strengthen your existing lashes and encourage healthy growth, leading to a wider-eyed finish, with or without your favourite magic wand.

Lash serums are certainly a hot topic right now – John Lewis reports a 430% rise in sales for The Ordinary Multi-Peptide Lash & Brow Serum in the last few weeks, heavily influenced by TikTok where there are 174.6million views for the hashtag #lashserum.

The Ordinary Multi-Peptide Lash & Brow Serum, £12.40, John Lewis

However, this is not just a flash in the pan trend – to help you make sense of the science, we asked the team at RevitaLash (Meghan Markle’s favourite, FYI), for some top lash serum tips.

How do lash serums work?

It takes three stages for your eyelashes to essentially replenish in their hair cycle:

  • Anagen-growth phase
  • Catagen-transition phase
  • Telogen-resting phase

‘It is during the anagen phase lasting 30-45 days that only 40% of your upper lashes and 15% of your lower lashes are growing at any one time,’ explains RevitaLash global ambassador Natalia Ferrara. ‘It can take 4-8 weeks to fully replace an eyelash. Lash pigment and follicle shrinkage happens in the catagen phase, and the lash sits in the telogen phase for over 100 days before the lash falls out and a new one is replaced.

‘When faced with stress, menopause (declining oestrogen levels), poor diet, topical stresses such as perming, tinting and lash extensions, the lash will not survive all three phases of the hair cycle. A good lash serum provides a healthy environment for your lashes to breathe and thrive by combating biological and topical stressors it allows for your lashes to survive all three phases of your hair cycle.’

When should you apply lash serum for the best results?

Use your lash serum at night on a clean dry lash surface, prior to your eye and skincare regime. They usually come with a small applicator brush, which you use to draw a thin line onto your eyelashes, as close to the lash line as you can – one brush stroke should be enough.

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How long does lash serum take to work?

There’s no one-size-fits-all answer to this question: some people see results in terms of improved lash condition and overall lash shine and flexibility in as little as a week, but for the full effect, it’s usually longer. ‘Generally we say 3-6 weeks to capitalise on the anagen phase of the hair cycle,’ Natalia says. ‘It’s important to be consistent and apply the serum once a day for at least three months to achieve full lash benefits.’

Are there any other products that stop lash serum from working?

Natalia advises that you avoid oil based eye make-up removers and cleansing oils, as these can create a barrier effect that will stop water-based lash serums like RevitaLash from working.

Are lash serums bad for your eyes?

‘I would always choose an eyelash conditioner that is ophthalmologist reviewed, dermatology reviewed and physician formulated and led –  just like I would use good quality skincare backed by and supported by a dermatologist,’ Natalia advises. ‘I would avoid preservatives such as PEG’s, gluten, parabens, non-vegan, non-cruelty free, oils and prescriptive lash serums whereby you do not have control over the product.’

‘High street chemist products containing castor oil do have some conditioning benefits but also contain preservatives,’ she adds.

How long do the effects of lash serums last?

Once you finish a tube, you’ll probably enjoy a couple more weeks of healthier, longer lashes, but it’s not a long-term solution and consistency is key. After a month or so, your lashes will likely return to their previous condition until you start applying lash serum again.

The best lash serum to buy for all budgets


RapidLash Eyelash Enhancing Serum, £31.95,  Feelunique

RapidLash is another major player in the long lash game, and those who stick with it through one tube tend to come back to it again and again. The secret to its success lies in its blend of polypeptides, biotin, and amino acids which help boost the protein structure of the hair.


Gosh Eyelash Growth Serum, £12.35, Amazon

Gosh’s £12 lash serum is one of the most highly-rated budget options. It’s especially good for giving a little extra TLC to lashes that are feeling the negative effects of long-term extension wear.


shiseido lash serum

Shiseido Full Lash Serum, £42, Cult Beauty

Shiseido is the hero of the J-Beauty industry, and quite rightly, as their products are consistently effective. This fast-absorbing lash serum uses arginine to condition and hydrate lashes and repair existing damage.


no7 lash serum

No7 Lash Impact Lash Serum, £16.95, Boots

You can always rely on No7 to create a dependable staple, and that’s just what it’s done here. For the price, it’s a great pick – give it the full recommended eight weeks to see the maximum benefit.


l'oreal lash serum

L’Oreal Paris Clinically Proven Lash Serum, £14.99, Amazon

L’Oreal’s hyaluronic acid-rich lash serum is unique in that you use it twice a day – once in the morning and again at night – to reap its benefits, but it’s worth the extra effort. 94 per cent of testers said it made their lashes look stronger.

UK Lash

Eyelash Growth Serum, £37,99, UK Lash

UK Lash’s formula has built a cult following, with more than 3,000 5-star reviews on its website. It’s also so confident in its abilities that it offers a money-back guarantee if you don’t see any results after eight weeks of use.


RevitaLash Advanced Conditioner, from £110, RevitaLash

The stars love it for a reason – RevitaLash is one of the bestselling and most recommended lash serums on the shelves. It’s ophthalmologist formulated and dermatologist reviewed, suitable for even the most sensitive of eyes.