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Twelve weeks, one ruler, the same score for everyone
A ranking is only worth reading if the method behind it is boring and identical for every product. Here is ours, including the parts that limit what our numbers can tell you.
Testers
UK-based, aged 21 to 58, recruited across eye colours and lash types, including four wearing extensions.
Weeks each
Nightly for the first eight weeks, then three nights a week, matching how these products are actually used.
Serums
The UK best sellers, bought at retail with our own money. No press samples, no brand-supplied units.
Photo points
Weeks 0, 4, 8 and 12, same camera, same distance, same ruler in frame.
The protocol
What each tester actually did
Baseline photograph
Clean, dry lash line, no mascara for 24 hours, with a millimetre ruler held against the outer lid in the same position each time.
One serum, one eye pattern
Each tester used a single serum for the full twelve weeks. Nobody ran two products at once, and nobody switched mid-trial.
A nightly log
Applications, missed nights, stinging, redness, dryness and anything else noticed — recorded on the day, not remembered at the end.
Measurement at four points
The longest third of the upper lash line is measured from the photographs at weeks 0, 4, 8 and 12 by someone who is not told which serum was used.
Panel averaging
The published figure is the mean gain across every tester on that serum, including the ones for whom it did little. Individual outcomes varied by roughly a millimetre either way.
The score
How the four columns add up
Each serum receives a mark out of ten in four columns. The weighted total is the number you see on the ranking card, rounded to one decimal place.
| Column | Weight | What moves it |
|---|---|---|
| Measured growth | 45% | Millimetres gained at week 12 |
| Safety & tolerance | 25% | Reported reactions; capped for prostaglandins |
| Formula | 20% | INCI quality and honesty of claims |
| Value | 10% | Cost per month of real use |
The prostaglandin cap
A serum containing a prostaglandin analogue cannot score above 5 out of 10 in the safety column, regardless of how our testers got on with it. The risks documented for these molecules build over years of use, and a twelve-week trial cannot see them. That cap is the reason the fastest-growing serum on our panel finished third rather than first.
What we cannot tell you
This is a consumer panel, not a clinical trial: no placebo arm, no laboratory conditions, and testers who knew which product they were using. It measures what happens when a real person uses a serum properly for three months. It does not establish medical efficacy or long-term safety, and we do not claim that it does.
Independence
Nothing here is for sale
Nothing on this site is monetised. No affiliate links, no advertising, no sponsored content — which means the ranking has no commercial reason to put one serum above another.
- Products bought at retail
- 12 of 12
- Brands consulted on the ranking
- None
- Paid placements available
- None, at any price
- Commission earned on a sale
- None — no affiliate links
The links beside each serum are ordinary references: they point at the brand’s own page, carry no tracking of ours and earn us nothing. If that ever changed, it would be written here first — a ranking that quietly starts selling is worth nothing to you and, shortly after, nothing to us.
Read the ranking the method produced
Twelve serums, scored on the four columns above.
Open the ranking →