A ranking is only as useful as the method behind it. This page sets out how we assess every serum in our 2026 ranking, so you can judge the results — and disagree with them — on the record.
1. Selecting products
We start with serums that are widely sold to UK customers, have a published full ingredient list, and are available from the brand or a UK retailer. Brands cannot pay for inclusion or for a position.
2. The panel
Each serum is used nightly for twelve weeks by testers with a mix of ages, lash types and skin sensitivity, including extension wearers. Testers follow the same application protocol and keep a simple diary of any reactions.
3. Photography and measurement
Lashes are photographed at weeks 0, 6 and 12 under the same lighting, distance and head position, with a macro lens and a chin rest. We compare visible length and fullness across the three sets of images.
4. Scoring
| Weight | Criterion | What we look at |
|---|---|---|
| 35% | Measured density and length | Change between week 0, 6 and 12 photos |
| 25% | Formula and actives | Active type and position in the INCI list, full disclosure |
| 20% | Tolerability | Stinging, redness, lid darkening, comfort on sensitive eyes |
| 12% | Value per night | Price divided by realistic tube life |
| 8% | UK availability | Stock, delivery and returns |
5. Updates
We review the ranking when prices change significantly, when a formula is updated, or when new evidence appears. The date at the top of the ranking shows the last full review.
6. Money
Some links on the site may earn a commission. That never changes a score or position. See our affiliate disclosure and editorial policy.
