Written by the Re:Cosm team · Last reviewed September 23, 2026 · Cosmetic information, not medical advice
In short: A humectant that becomes vitamin B5 on skin and hair. It draws moisture into the lash, improving flexibility and reducing the brittleness that leads to breakage.
What it is
Panthenol is the alcohol form of pantothenic acid, vitamin B5, which is why it is called pro-vitamin B5. It is one of the most widely used conditioning ingredients in hair care, with decades of formulation history in shampoos, conditioners and styling products.
How it works on lashes
Panthenol is a humectant: it attracts and holds water. Unlike many humectants it is small enough to move into the outer layers of the hair shaft, where it improves moisture content from within. Hydrated hair is more flexible, and flexible hair bends instead of snapping.
That matters for lashes more than for most hair. Lashes are short, they are rubbed every day by pillows, mascara removal and fingers, and they are repeatedly stressed by curlers, lifts and extension adhesive. Breakage is one of the main reasons lashes look sparse, so an ingredient that keeps them supple has a visible effect over weeks.
After a lash lift, tint or extensions
Lifts and tints use chemistry that leaves lashes drier than before. Once the 24 to 48 hour aftercare window has passed, a panthenol based, oil-free serum is one of the simplest ways to restore moisture. Under extensions it conditions the natural lashes that the extensions depend on, without the oils that weaken adhesive.
Where it sits in the Re:Cosm formula
Re:Cosm Lash Conditioning Serum has 29 ingredients, and this page covers one part of that formula: a prostaglandin-free, fragrance-free and oil-free peptide serum made in Korea by Kolmar Korea. Every ingredient and the job it does is decoded on the lash serum ingredients guide, and the full label is on the product page.
Common questions
Is panthenol good for eyelashes?
Yes. It is a well established humectant that improves the moisture and flexibility of hair, and lashes are hair. Flexible lashes break less.
Is panthenol safe with lash extensions?
Panthenol itself is water soluble and does not affect extension adhesive. Check that the rest of the formula is oil-free.
What is the difference between panthenol and vitamin B5?
Panthenol is the form used in cosmetics. It converts to pantothenic acid, vitamin B5, on contact with skin and hair.
Other ingredients in the formula
- Acetyl Tetrapeptide-3 and Capixyl™
- Biotin
- Hyaluronic Acid (Hydroxypropyl Trimonium Hyaluronate)
- Centella Asiatica, Licorice Root and Houttuynia Cordata
Also worth reading: lash serum ingredients to avoid and what prostaglandin-free means.
Sources and standards
Ingredient facts are checked against our published formula and the sources below. We describe how lashes look and feel, never growth: that is a drug claim, and our serum is a cosmetic.
See the whole formula
Prostaglandin-free. Fragrance-free. Oil-free. Every ingredient published.
View Lash Conditioning Serum