TIRTIR PHA 15% Serum 30ml
PHA 15% Serum, TIRTIR's gentle chemical exfoliant serum built on Gluconolactone rather than glycolic acid. It is part of TIRTIR's Korean-market skincare lineup.
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- Suited to
- Skin looking to add a targeted treatment step to an existing routineDehydrated or tired-looking skin needing a hydration boostSkin new to the specific active this serum is built around
- Helps with
- Skin new to chemical exfoliation or sensitive to AHA/BHAA gentler nighttime exfoliating stepDull, uneven texture that wants smoothing without irritation
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How it works
Gluconolactone is a polyhydroxy acid, a gentler cousin of the AHA family that exfoliates with a larger molecule size than the smaller-molecule AHAs it does not contain, which is why PHA formulas are the usual starting point for exfoliation-sensitive skin. Squalane and Adenosine sit in the base to keep the exfoliating serum from feeling stripping, and a run of fruit and root extracts, including Vaccinium Myrtillus (bilberry), sugarcane and lemon, rounds out a formula built around gentle acid exfoliation rather than one active alone. It is meant to follow toner and precede a moisturizer, applied to skin that is still slightly damp so the actives have a receptive surface to absorb into. This particular listing is the 30ml size TIRTIR sells for the line, packaged and formulated for the Korean market rather than a separate US release.
Key benefits
- Gluconolactone (PHA), rather than a smaller-molecule AHA, for gentler exfoliation
- Squalane and Adenosine to offset stripping
- Bilberry, sugarcane and citrus fruit extracts in the base
- Built for exfoliation-sensitive skin starting out with acids
- Sold as TIRTIR's authentic Korean-market formula, the same version sold through Korean retail rather than a US-reformulated substitute
Key actives
AdenosineSkin-soothing nucleoside
A naturally occurring skin nucleoside included in most modern Korean formulas for its soothing, texture-supporting role, almost always used at a low, well-tolerated concentration.
SqualaneLightweight emollient
A plant-derived emollient that mimics the skin's own natural oils, chosen across Korean formulas for a lightweight, fast-absorbing feel rather than a heavy, greasy one.
GluconolactonePolyhydroxy acid (PHA)
A polyhydroxy acid with a larger molecule size than the smaller-molecule AHAs it does not contain, which is why PHA formulas are typically the gentler starting point for skin new to chemical exfoliation.
TocopherolVitamin E, antioxidant
Vitamin E, a widely used antioxidant that also helps stabilise a formula's other oil-soluble ingredients against breaking down over the product's shelf life.
glycerinHumectant
A basic, well-tolerated humectant that draws water to the skin's surface, doing quiet supporting work in almost every Korean skincare and base makeup formula.
Is PHA gentler than a standard AHA exfoliant?
Yes. Rather than a smaller-molecule AHA, Gluconolactone's larger molecule size means it exfoliates the skin's surface more gradually, which is why PHA formulas are typically recommended for sensitive or acid-new skin.
How often should I use this?
Start two to three nights a week and increase only if skin tolerates it well, the same introduction pace recommended for any new exfoliating acid. This is general guidance rather than a fixed rule, so adjust it based on how your own skin or the product itself responds.
Do I need sunscreen when using this?
Yes, every day this is in the routine. Any exfoliating acid increases how easily skin sunburns, so daytime sun protection is a separate, necessary step. This is general guidance rather than a fixed rule, so adjust it based on how your own skin or the product itself responds.
Is this the same formula sold in Korea, or a version made for the US market?
This is TIRTIR's Korean-market formula, sourced and shipped with its original Korean-market packaging and batch coding rather than a separate US-reformulated version. Korean Pharmacy stocks the exact SKU sold through Korean retail rather than a substitute built for US shelves, which is the point of buying from a specialist rather than a general beauty retailer.
How should I store this to keep it in good condition?
Keep the cap or compact closed between uses and store it away from direct sunlight and heat, the same way you would any cosmetic. A cool, dry spot such as a drawer or cabinet keeps the texture and finish consistent for longer than leaving it exposed on a warm windowsill or in a hot car.
- Ships from
- California
Duties are prepaid. Nothing is owed at delivery. Returns are accepted for 30 days, by mail.
Orders ship from our California warehouse, dispatched within 2 business days, and arrive in 3 to 5 days. Shipping is free on orders of $100 or more.
We split shipments free, so one out-of-stock item never holds up the rest of your order.
Where this unit came from
- 1Seoul
Bought as Korean-market stock - 2Customs
Duty paid by us before it enters the US - 3California
Ships domestically, no international leg
We stock the version of a formula that is sold in Korea, not the release a brand prepares for another market under the same name.
Every unit keeps its original barcode and batch code intact, so the unit in your hands can be checked against the brand’s own records.
Import duties are paid by us before the parcel reaches you, so nothing is owed at the door, and returns run for 30 days.
Every claim on this page traces to the unit in the box, the barcode, the batch code and the price you can read for yourself.
Payment and security
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How to use
- Apply to clean, dry skin at night, starting two to three times a week rather than daily until skin has adjusted. Follow with a moisturizer, and always use daytime sun protection separately since any acid exfoliant increases sun sensitivity.
Worth knowing
- Introduce any new active serum gradually, a few nights a week at first, rather than daily right away.
- Follow an exfoliating or retinoid-containing serum with daytime sun protection the next morning as a separate step.
Reviews
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Korean-market original
Exfoliation, without the sting of a smaller-molecule acid.
Verify your unit when it arrives
Verify your unit when it arrives
Korean-market stock with the original barcode and batch code intact, exactly as it left Korea.
Match the batch code on the box against the code printed on the bottle or tube itself; the two are stamped separately and should agree.
On the unit itself
- The Korean-market barcode, unaltered from the retail package.
- The manufacturer’s batch code, exactly as the maker printed it.
정품Genuine article, Korean-market stock
What professionals say
What professionals say
What skin-care professionals say about the key actives in this formula, quoted from the medical sources linked beside each.
Squalane comes from a lipid that occurs naturally in your skin.
Alok Vij, MDDermatologist, Cleveland Clinic People with dry, flaky skin are more likely to see a benefit from using vitamin E because it enhances moisturization.
Amy Kassouf, MDDermatologist, Cleveland Clinic
1 more professional perspective
This means that gluconolactone acts as an exfoliating acid, but also as a moisturizer. It has moisturizing, soothing, and lightening properties, working well on dry skin.
Paola PeruginiPhD, Journal of Cosmetic Dermatology
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