Galactomyces is a type of yeast. Ferment that yeast and strain out the liquid and you get galactomyces ferment filtrate, the ingredient that carried K-beauty essences into their golden age. SK-II's famous "Pitera" is exactly this filtrate. The story goes that researchers in the 1970s noticed how unusually smooth the hands of elderly sake brewers were and traced it back to the yeast. The ingredient works on several fronts at once, from refining texture to lifting clarity and holding in moisture.
The short version Galactomyces ferment filtrate is a fermented liquid that naturally carries several kinds of amino acids along with vitamins, minerals and organic acids. It tends to show the clearest results in products that contain 90% or more of it.
| Also known as | Pitera (SK-II), Galactomyces Ferment Filtrate, GFF |
|---|---|
| Family | Fermented yeast extract |
| EWG rating | 1 (very safe) |
| Pregnancy & breastfeeding | Generally considered usable (check with your doctor) |
| Photosensitivity | None (use day or night) |
| Key benefits | Texture, clarity, hydration, pores |
It keeps the cycle of shedding old cells and bringing up new ones running on a steady rhythm. That smooths the surface and adds a little shine. Run it for four to eight weeks and the first change you notice is usually a dull tone turning brighter.
Fermentation creates natural moisture-binding ingredients called humectants that draw water into the outer layer of skin. It does not sit heavy on the face. It simply tops up hydration with a light touch, which is why it suits every skin type.
It helps regulate how much oil comes through and keeps surface cells tidy, so pores look smaller. The difference shows up most around the nose and on the larger pores of the cheeks.
Several B vitamins and antioxidants in the filtrate slow the formation of dark pigment (melanin) and ease the discoloration that comes from oxidative stress. The change is gradual rather than instant. Keep at it for twelve weeks or more and the complexion settles into a noticeably more even tone.
A synthetic ingredient isolates one active molecule and concentrates it. A fermented extract works the other way. It is a blend of dozens or even hundreds of compounds that the microbes produce on their own. The galactomyces filtrate carries a mix like this.
Because all of these work together, the filtrate stays gentle on skin while still delivering visible results.
The molecules in galactomyces filtrate are small enough to absorb quickly into the outer layer of skin. Once they are in, they encourage the cells that form the surface (keratinocytes) to renew themselves and support healthy keratin production. The result is a smoother, more refined texture.
The vitamin B3 (niacin) family in the filtrate plays a second role here. It holds back the transfer of dark pigment (melanin) to neighboring cells and supports the production of NAD+, the molecule cells lean on to make energy. That steadier energy metabolism is where the "my skin looks brighter" feeling comes from.
Pitera™ is the trademark SK-II gives to its own galactomyces ferment filtrate. In other words, Pitera is SK-II's take on galactomyces filtrate. Other brands draw their galactomyces ferment filtrate from the same yeast.
The differences come down to a few things: the exact strain of yeast, the fermentation conditions of temperature, time and nutrients, and the way it is filtered. SK-II leans on decades of know-how. That said, galactomyces formulas at 95% or higher from brands like Missha and COSRX are worth considering for similar benefits.
More ingredient guides
VERIFIED DUPES
Verified dupe pairs featuring Galactomyces: 9
Pairs confirmed by comparing both full ingredient lists.
The information on this page is written for general cosmetic-ingredient education. It does not replace medical diagnosis, prescription, or treatment.
If you notice an adverse reaction, stop using the product immediately and see a professional.
Found this useful?
