Mediheal
N.M.F Intensive Hydrating Mask
Key ingredient: NMF + Hyaluronic Acid
For acute dehydration — post-flight skin, post-illness skin, the morning after a heavy night out — the Mediheal N.M.F Intensive Hydrating Mask delivers a single-use 27ml serum saturated with Natural Moisturising Factor components (HA, amino acids, sugars, urea derivatives) in a sheet format that holds the active layer against skin for 20 minutes — the most-bought sheet mask in K-beauty history.
The ingredient story
Hero ingredient
NMF (Natural Moisturising Factor) complex
Concentration
NMF is the natural humectant system the skin produces itself — a mix of free amino acids, urea derivatives, sugars, and salts that bind water in the stratum corneum. This mask delivers the externally-sourced versions: Hydroxyethyl Urea (urea-derivative humectant), Trehalose (sugar humectant), Betaine, Arginine (amino acid), and Sodium Hyaluronate. Combined with Willow Bark Extract (mild salicylic acid for surface exfoliation) and Panthenol for skin-softening.
Deep-dive
Read the full guide →How it works
The skin's natural NMF gets depleted by over-cleansing, low humidity, illness, and aging — that depleted skin feels tight regardless of how much serum you apply, because the humectant system that holds water inside the stratum corneum is missing. Topical NMF (the components in this mask) refills that humectant system from the outside, restoring the skin's own ability to hold water. The sheet-mask format isn't marketing — pressing the saturated cellulose against skin for 20 minutes physically prevents the actives from evaporating, increasing absorption vs the same serum applied as a leave-on.
What the evidence shows
NMF replenishment as a barrier-repair strategy is one of the most-studied mechanisms in cosmetic dermatology (Rawlings & Harding, 2004 — review of NMF and skin hydration). Mediheal's 2009-launched line has been continually reformulated and is the most-frequently-purchased K-beauty sheet mask globally (over 1.6 billion units sold since launch).
Willow Bark Extract contributes mild surface BHA activity — patch-test on highly reactive skin before nightly use. Pregnancy-safe at this dose. Single-use packaging prevents bacterial contamination.
The brand
Philosophy
“Industrial-scale, dermatology-derived sheet masks at drugstore prices. Pioneer of 100% automated mask manufacturing in Korea.”
Mediheal was launched in 2009 by L&P Cosmetic Co. as a sheet-mask-first Korean indie focused on industrial-scale dermatology-derived sheet masks. The company was the first in Korea to use 100% automated mask manufacturing — meaning the cellulose sheets are saturated and packed without human contact, eliminating bacterial-contamination risk that plagued the early Korean sheet mask category. By 2015 Mediheal had become Korea's #1 sheet mask brand by units sold; by 2019 it had crossed 1 billion units sold globally. The N.M.F Intensive Hydrating mask is the anchor SKU within the brand — the mask Korean shoppers buy by the box (10-pack) for routine 2–3x weekly use, and the mask Western shoppers buy as their first K-beauty sheet mask trial. Mediheal's broader range covers a dozen targeted concerns but the colour-coded line is the recognisable identity: red NMF for hydration, green tea tree for blemishes, blue Madecassoside for redness, white collagen for firming.
Where this fits in your routine
Routine step
Sheet mask — 2–3x weekly, evening, replaces toner-essence-serum steps for that night
After cleansing, place the sheet on clean dry skin. Smooth out air bubbles. Leave on for 15–20 minutes (set a timer — over-use causes the dried-out sheet to wick moisture OFF skin, the opposite of intended). Remove and gently pat remaining essence into skin. Skip toner, essence, and serum for that night — the mask delivers all three. Apply moisturiser as normal to seal.
Cadence: 2–3 nights a week for hydration maintenance. Nightly during acute dehydration (post-flight, post-illness, winter). Once weekly during normal periods.
Layers especially well with: any moisturiser to seal (AESTURA, Dr.Jart+ Ceramidin, COSRX Advanced Snail Cream).
Avoid: active treatment nights (retinol, AHA, BHA) — use the mask on rest nights instead to recover from those. Do NOT sheet mask post-exfoliation; the actives in the mask can sting on freshly exfoliated skin.
Pregnancy-safe. The Willow Bark BHA content is too dilute to be of concern at this dose.
Note on sheet masks generally: Korean sheet masks are designed to be 15–20 minute treatments, not hour-long sessions. Leaving a mask on past 25 minutes lets the cellulose dry out and reverses the hydration effect.
Pairs especially well with
COSRX Advanced Snail 96 Mucin Power Essence — mask night + snail night = the K-beauty "skin emergency" combo for post-flight, post-illness recovery
AESTURA Atobarrier 365 Cream — sheet mask first to load humectants, AESTURA cream after to seal in the moisture overnight
Round Lab 1025 Dokdo Toner — mask on hydration-emergency nights, 1025 toner as the daily baseline — both K-beauty minimalist hydration leaders
Full ingredients
Free from
Full INCI ingredient list (manufacturer)
Water, PEG/PPG-17/6 Copolymer, Glycereth-26, Glycerin, 1,2-Hexanediol, Salix Alba (Willow) Bark Extract, Butylene Glycol, Xanthan Gum, Hydroxyethyl Urea, Panthenol, Trehalose, Betaine, Arginine, Polysorbate 80, Carbomer, Sodium Hyaluronate, Aloe Barbadensis Leaf Extract, Hydrolyzed Collagen, Hamamelis Virginiana (Witch Hazel) Extract, Tromethamine, Disodium EDTA, Allantoin, Citric Acid, Hydroxyacetophenone, Phenoxyethanol
What real users say
“I buy these by the box (10-pack from Olive Young when I visit Seoul). Three a week and my skin stays plump through London winters. Cheapest "miracle" in my routine.”
— r/SkincareAddictionUK, 2024
“The mask after a flight is non-negotiable in my routine now. I land, shower, mask, and the dehydration that used to take three days to recover is gone by morning.”
— Reddit r/AsianBeauty, 2024
“1.6 billion sold is not an accident. This is the sheet mask that defined the category — pleasingly simple, consistently effective, drugstore-cheap.”
— TikTok review with 1.2M views
Texture / feel
Generously saturated cellulose sheet — leaves measurable essence in the pouch even after 20 minutes wear. Cold from the fridge is preferred (extra de-puffing). Fragrance-free with a clean mild scent from the willow bark and witch hazel extracts. The cellulose sheet itself is the standard Korean weave — comfortable enough to lie down with, not the more advanced bio-cellulose used by luxury sheet masks.
Buying authentic
Verified UK retailers
Counterfeit warning
Mediheal counterfeits exist on Amazon UK marketplace third-party sellers and Korean shopping middleman services. Genuine masks have crisp Korean printing on individual pouches with a clear lot code. Box should show the L&P Cosmetic manufacturing reference. Buy authentic 10-pack boxes from listed retailers rather than singles from marketplace sellers.
This page was last reviewed on 2026-05-21. We update product storytelling when formulation, retailer availability, or evidence changes meaningfully.
About this product
Korea's #1 selling sheet mask with Natural Moisturising Factor complex. Delivers intensive hydration in 15 minutes, plumping dehydrated skin instantly.
Why NMF + Hyaluronic Acid works
NMF + Hyaluronic Acid attracts and holds up to 1,000× its weight in water, plumping dehydrated skin from within.
Best for these skin types
Concerns addressed
Ceramides, centella asiatica, and panthenol are the gold standard for rebuilding a compromised barrier.
