Lash serum ingredient lists are short enough to actually read — most are 10 to 20 ingredients, not the 40-item lists you see on some skincare. That makes label-checking genuinely practical. Here's what we'd flag if we were reading someone else's box, and what we chose instead in our own Lash Serum.
Prostaglandin analogues
Covered in depth in our side-effects guide, but the short version: ingredients like isopropyl cloprostenate or bimatoprost are linked to permanent iris darkening in light-coloured eyes, plus documented irritation and orbital fat loss with prescription-strength use. Check the INCI list for anything containing "prost" or described as a "prostamide."
Heavy oils, near the lash line
Oil-based serums can migrate into the eye and, more practically for extension wearers, dissolve lash-extension adhesive. If you wear extensions or have had a lash lift, check with your technician before using any serum. Our own formula uses PEG-40 Hydrogenated Castor Oil as a water-soluble solubiliser (not a free oil) — it doesn't behave like an oil on the lash line, which is why we say “no free oils” rather than “oil-free”.
Undisclosed fragrance in an eye-area product
Fragrance is one of the most common causes of eye-area irritation, and "fragrance" or "parfum" as a single catch-all ingredient can hide dozens of individual compounds. For a product used daily, centimetres from your eyes, we'd want to see either no added fragrance or a fully disclosed one.
Vague "clinically proven" claims with no study behind them
This isn't an ingredient, but it's a label red flag: a claim like "clinically proven" should point to an actual study — sample size, duration, whether results were self-reported. If a brand can't produce that, treat the claim as marketing rather than evidence.
What we did include, on purpose
| Ingredient | Why it's there |
|---|---|
| Acetyl Tetrapeptide-3 | Conditioning peptide, part of our core active blend |
| Biotinoyl Tripeptide-1 | Conditioning peptide |
| Biotin | Common conditioning active in lash and brow formulas |
| Panthenol | Humectant, helps the formula feel smooth on application |
FAQ
Is "prostaglandin-free" on the label enough to trust?
It's a good filter, but check the actual INCI list too — the safest check is looking for the ingredient itself, not just a marketing claim.
Are all oils bad in a lash serum?
Not inherently — the concern is specifically free oils that can migrate into the eye or affect extension adhesive. Water-soluble, ethoxylated ingredients derived from oils (like the solubiliser in our own formula) don't behave the same way.
What if a serum doesn't list full ingredients online?
That's itself a reason for caution — a brand confident in its formula usually publishes the full INCI list, not just headline actives.
Does LashOriginals publish its full ingredient list?
Yes — see the ingredients section on the Lash Serum product page.