Eyelash and eyebrow growth serums: what is in them
Peptides, conditioning ingredients and prostaglandin analogues – how to recognise them on the label and what the EU safety assessment says.
Updated: 31 October 2026 · Reviewed by: Kamil Pyziak
Three groups of ingredients
Lash and brow serums usually fall into one of three groups. Some are simple conditioners with humectants and vitamins, such as panthenol, glycerin or biotin. Others are built around peptides – short chains of amino acids with names such as myristoyl pentapeptide-17 or myristoyl hexapeptide-16. A third group contains prostaglandin analogues, substances chemically related to compounds used in some prescription eye drops.
The INCI list is the quickest way to tell which group a product belongs to. Marketing names such as “lash complex” or “growth formula” do not say which ingredients do the work.
Peptides
Peptides are listed under their INCI names, often with a fatty acid attached (myristoyl, palmitoyl) to make them easier to formulate. They are typically used at low concentrations and appear in the second half of the list.
Manufacturers’ claims about peptides are usually based on their own studies. The ingredient list shows that a peptide is present, but not how much of it there is or how the claim was tested.
Prostaglandin analogues
Prostaglandin analogues are recognisable by names such as isopropyl cloprostenate, methylamido-dihydro-noralfaprostal or ethyl tafluprostamide. Related substances are used in medicines for glaucoma, where changes in eyelash growth were observed as a side effect.
In medicines these substances are known to cause effects such as eye redness, irritation, darkening of the eyelid skin and, in some cases, changes in iris colour. That is why their use in cosmetics has been reviewed by EU safety experts.
What the EU safety assessment says
The EU Scientific Committee on Consumer Safety (SCCS) has issued a scientific opinion on prostaglandin analogues used in eyelash and eyebrow products. The committee assessed specific substances at specific concentrations and drew conclusions on which uses it considered safe.
An SCCS opinion is scientific advice, not a law. Any limits that apply on the market are set later in the Cosmetics Regulation annexes. For the current wording, read the opinion itself (linked on the ingredient pages) and check the EU regulation section of each ingredient.
Practical tips
Apply a lash serum only to the base of the upper lashes, as the instructions say, and avoid getting it into the eye. Stop using the product if you notice redness, itching, swelling or changes in the colour of the skin around the eye.
If you have an eye condition, wear contact lenses, are pregnant or breastfeeding, or use eye drops, ask an eye doctor or pharmacist before using a serum with a prostaglandin analogue.
What the label does not tell you
The INCI list does not reveal concentrations, so it cannot show whether a prostaglandin analogue is present at a level the SCCS assessed. It also does not tell you how long it takes to see an effect or what happens after you stop using the product.
Use the ingredient checker to identify each substance, and treat claims of growth with the same caution as any other cosmetic claim.