Lash serum ingredients, explained
An ingredient list shouldn't require a chemistry degree. Here's what each key ingredient in a peptide lash serum actually does — in plain language.
Acetyl Tetrapeptide-3 (Capixyl™)
What it is: A biomimetic peptide — a small chain of amino acids designed to mirror ones your body already uses.
Why it's here: Paired with red clover (Trifolium pratense) extract in the Capixyl™ complex, it conditions the lash line and supports the look of fuller, denser lashes. It's the centerpiece of the prostaglandin-free approach.
Biotin (Vitamin B7)
What it is: An essential water-soluble B-vitamin, sometimes called vitamin H.
Why it's here: Lashes are made of keratin, and biotin is a natural building block in keratin formation — supporting stronger-looking, more resilient lashes.
Panthenol (Pro-Vitamin B5)
What it is: A humectant that converts to vitamin B5 on contact with skin and hair.
Why it's here: It penetrates the lash cuticle to deliver hydration, improving flexibility and reducing the brittleness that leads to breakage.
Centella Asiatica Extract
What it is: A botanical long used in Korean skincare, also known as cica or tiger grass.
Why it's here: The skin along your lash line is some of the thinnest on your body. Centella calms and soothes it, keeping the area comfortable for nightly use.
Hydroxypropyl Trimonium Hyaluronate
What it is: A modified form of hyaluronic acid engineered to bind to hair fibers rather than rinse away.
Why it's here: It locks moisture onto the lash itself and forms a light protective film against daily environmental stress.
Houttuynia Cordata & Licorice Root (Dipotassium Glycyrrhizate)
What it is: Two soothing botanicals common in K-beauty formulas.
Why it's here: They comfort the delicate periorbital skin and help reduce the look of redness — part of why the formula suits sensitive eyes.
What's deliberately not here
No prostaglandin analogs (see our guide on why), no fragrance, no parabens. For the delicate eye area, what a formula leaves out matters as much as what it puts in.
See every ingredient
The complete INCI list for Re:Cosm Lash Conditioning Serum is published on the product page.
View the full formula