COSRX
COSRX Low pH Good Morning Gel Cleanser
The low-pH claim you can check yourself.
Sodium benzoate only works below about pH 5.5 — its presence on the list is the proof.
Slippery gel, modest foam.
What this cleanser does
A 150 ml gel cleanser built on two mild surfactants at an acidic pH, with Betaine Salicylate, tea tree leaf oil and a seven-part botanical complex.
Three ways this label confirms the name
"Low pH" is a claim you cannot see, taste or feel with certainty. But the ingredient list contains three independent pieces of evidence.
One: there is no hydroxide. No potassium hydroxide, no sodium hydroxide, no fatty acid to saponify. Nothing here can make soap, and soap is what forces a cleanser alkaline.
Two: citric acid is present, at position nineteen, doing the acidifying.
Three: sodium benzoate is the preservative. This is the interesting one. Sodium benzoate only functions in its active form in an acidic environment — above roughly pH 5.5 it stops protecting the product. No formulator would choose it for a formula that was not genuinely acidic, because the product would spoil. The preservative is circumstantial evidence, and it agrees with the other two.
Three independent lines from one label. That is what a claim looks like when it is true.
Why an acidic cleanser is worth wanting
Healthy skin surface sits around pH 4.5 to 5.5. The enzymes that let dead surface cells detach work in that band, and so does the microbial population living there. Wash with something alkaline and it takes hours to recover — which is fine occasionally and less fine twice a day, every day.
That is the whole argument for this product, and it is a good one.
There is a BHA in here
Betaine Salicylate at position eighteen is salicylic acid bound to betaine — a gentler, slower-releasing BHA. Unlike its sibling the Salicylic Acid Daily Gentle Cleanser, which is a soap and therefore alkaline, this formula is acidic enough for a salicylate to be in a working form.
Contact time is still short. Do not expect a rinse-off product to replace a leave-on BHA. But it is genuinely present and genuinely in a usable state, and if you already use acids elsewhere it is worth counting as one more exposure.
One thing to weigh
Tea Tree Leaf Oil at fourteen is an essential oil in a product bought largely by people with sensitive skin. It is above the allantoin and above the BHA. Small, but there — and if you react to tea tree, this is why.
Key ingredients
Ingredient · What it is, and what it is used for
- Cocamidopropyl Betaine
- Betaine surfactant. Does the cleansing — mild, and stable at low pH. Second on this list.
- Sodium Lauroyl Methyl Isethionate
- Isethionate surfactant. Does the cleansing — one of the mildest in wide use, and it foams well in soft water.
- Betaine Salicylate
- Salicylic acid bound to betaine. A slower-releasing BHA — oil-soluble, so it works inside the follicle.
- Citric Acid
- Alpha hydroxy acid, used here as pH adjuster — this is what sets the low pH.
- Sodium Benzoate
- Salt of benzoic acid. Only works as a preservative below about pH 5.5 — evidence the formula is acidic.
- Styrax Japonicus Branch/Fruit/Leaf Extract
- Extract of Japanese snowbell. Fifth on this list, which is high for a botanical.
- Saccharomyces Ferment
- Yeast ferment. First entry of the seven-part botanical block.
- Cryptomeria Japonica Leaf Extract
- Extract of Japanese cedar leaf. Pulls water into the surface and holds it there.
- Pueraria Lobata Root Extract
- Extract of kudzu root. Pulls water into the surface and holds it there.
- Melaleuca Alternifolia (Tea Tree) Leaf Oil
- Essential oil of tea tree leaf. Carries scent.
- Allantoin
- Heterocyclic diureide. Used to calm irritation.
- Trisodium Ethylenediamine Disuccinate
- Biodegradable chelator. Binds hard-water metal ions so the surfactants keep working.
How the formula works together
Only three cleansing agents, and none of them harsh: Cocamidopropyl Betaine, Sodium Lauroyl Methyl Isethionate and Polysorbate 20. That is a deliberately weak cleansing system — which is the point of a morning wash, where there is nothing on your face but last night's skincare.
Positions seven to thirteen are the botanical block — yeast ferment, Japanese cedar leaf, lotus leaf, longleaf pine, elm root, evening primrose flower and kudzu root. That same seven appears in the Salicylic Acid Daily Gentle Cleanser, lower down its list. One prepared complex, used across the range.
Two chelators rather than one, which suggests this was formulated with hard water in mind.
Who it is for
Labelled for all skin types. Built as a morning cleanser and as a second cleanse at night. Genuinely gentle and genuinely acidic; contains a BHA and tea tree oil. It will not remove sunscreen or makeup on its own — the brand says to use it after a first cleanse, and that is correct.
How to use it
- Morning: massage a small amount over a wet face, then rinse with lukewarm water.
- Evening: use it as the second step, after an oil cleanser or balm.
- A little goes far — it is a low-foam gel by design, not by weakness.
- Follow with toner while skin is still damp.
Details
- Size
- 150 ml
- Made in
- Korea
- Cleansing system
- Soap-free, acidic — no hydroxide anywhere on the list
- Contains
- Betaine Salicylate (a BHA) and tea tree oil
- Ingredients
- 24, published in full below
Full ingredient list
Water, Cocamidopropyl Betaine, Sodium Lauroyl Methyl Isethionate, Polysorbate 20, Styrax Japonicus Branch/Fruit/Leaf Extract, Butylene Glycol, Saccharomyces Ferment, Cryptomeria Japonica Leaf Extract, Nelumbo Nucifera Leaf Extract, Pinus Palustris Leaf Extract, Ulmus Davidiana Root Extract, Oenothera Biennis (Evening Primrose) Flower Extract, Pueraria Lobata Root Extract, Melaleuca Alternifolia (Tea Tree) Leaf Oil, Allantoin, Caprylyl Glycol, Ethylhexylglycerin, Betaine Salicylate, Citric Acid, Ethyl Hexanediol, 1,2-Hexanediol, Trisodium Ethylenediamine Disuccinate, Sodium Benzoate, Disodium EDTA
In label order, unedited.
Ships from Korea.
