A two-week treatment for soft nails that bend, split and break
Herôme Nail Hardener Strong is a clear hardening varnish for soft, thin and brittle nails that break before they can grow. It hardens the keratin of the nail plate so nails become firmer and less likely to split or peel, and it lets them grow longer without snapping. A 15-day course is usually enough to see nails that feel harder and stronger. After the course, the same bottle works as a base coat under your usual polish, as a clear top coat that adds shine, or as a protective layer on bare nails. The formula contains no TFS resin and no toluene.
How it works
The active ingredient is a small amount of formaldehyde, which binds the keratin fibres of the nail together and makes the free edge firmer. Applied in thin layers on the nail only, it dries to a clear, glossy finish.
Who it suits
- Soft, thin nails that bend and tear easily
- Nails that split or peel in layers
- Anyone growing out nails after acrylics or gel
- People who want one clear coat that also works as a base and top coat
Worth knowing before you buy: this hardener contains formaldehyde. Apply it only to the nail, keeping it off the cuticles and surrounding skin, and do not use it on damaged, infected or very dry nails. Stop the course once nails feel hard enough, as overuse can make them rigid and brittle.
How long one bottle lasts
One 10ml bottle covers several 15-day courses and months of use as a base or top coat.
Complete the routine

Herôme Cuticle Cream
Softens and nourishes dry cuticles.
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Vitry Ceramic Nail File
Files fragile nails smoothly without splitting them.
Shop →Characteristics
- Texture: clear nail varnish
- Nail type: soft, thin, brittle and splitting nails
- Concerns: breakage, splitting, peeling
- When to apply: in the evening, as a 15-day course
- Main benefits: hardens soft nails, reduces splitting and breakage, helps nails grow longer, can be used as a base or top coat
- Formulated without: TFS resin, toluene
How to use
Apply to clean, dry nails in the evening for at least 15 days. Day 1: apply one thin coat to the nail only, without touching the cuticles. Day 2: apply a second coat. Day 3: remove the varnish. From day 4, start the cycle again. After the course, use it as a base coat, top coat or protective clear coat.
Active ingredients
- Formaldehyde: hardens the keratin of the nail plate
- Nitrocellulose and film formers: form a clear, protective, glossy film
- Acetyl tributyl citrate: keeps the film flexible
Ingredients
BUTYL ACETATE · NITROCELLULOSE · ETHYL ACETATE · HEPTANE · ISOPROPYL ALCOHOL · ACETYL TRIBUTYL CITRATE · ADIPIC ACID/ISOPHTHALIC ACID/NEOPENTYL GLYCOL/TRIMETHYLOLPROPANE COPOLYMER · FORMALDEHYDE · TOSYLAMIDE/EPOXY RESIN · STEARALKONIUM HECTORITE · CI 77891 · DROMETRIZOLE · STYRENE/ACRYLATES COPOLYMER · CAMPHOR · OXIDIZED POLYETHYLENE
Formulations are updated by the manufacturer from time to time. Always check the packaging you receive.
Manufacturer information
Brand: Herôme Cosmetics B.V.
Address: De Paal 18, 1351 JC Almere, Netherlands
EAN: 8711661004345
