What Is Galactomyces?
Galactomyces is a genus of yeast — a single‑celled fungus — that produces a filtrate during the fermentation process containing a complex mixture of amino acids, vitamins, minerals, organic acids, and polysaccharides. In skincare, it is the filtered and sterilised liquid collected from this fermentation that is used as the active ingredient.1
The fermentation of yeast has been used in food production for thousands of years, but its skincare application was discovered in Japan in the 1970s when researchers noticed that sake brewery workers had remarkably smooth, youthful hands despite harsh working conditions. Investigating this phenomenon led to the identification of galactomyces ferment filtrate as the active agent — and to the development of SK‑II’s Pitera™, one of the most commercially successful skincare ingredients of the last forty years.
Korean cosmetic chemists later reverse‑engineered and improved upon the formulation, producing high‑concentration galactomyces products at dramatically lower price points. The Some By Mi, MISSHA, and COSRX galactomyces ranges deliver comparable or superior active concentrations to SK‑II at 10–20% of the cost.
The SK‑II Connection — Same Ingredient, Fraction of the Price
SK‑II’s Facial Treatment Essence (approximately £130–160 for 230ml) is one of the bestselling luxury skincare products globally. Its primary active ingredient — Pitera™ — is galactomyces ferment filtrate produced from the yeast strain Saccharomyces cerevisiae. SK‑II holds the Pitera™ trademark but the ingredient itself, produced from similar or identical fermentation processes, is freely available in Korean skincare.
The MISSHA Time Revolution First Treatment Essence (approximately £20–35) contains galactomyces ferment filtrate at comparable concentrations and is explicitly marketed as a Korean alternative to SK‑II’s Pitera Essence. Independent consumer testing and cosmetic chemistry analysis consistently shows comparable performance on brightening and texture outcomes.
What Galactomyces Ferment Filtrate Contains
The bioactive content of galactomyces filtrate is what makes it distinctive — it is not a single compound but a complex mixture produced during fermentation:
Vitamins — B vitamins (B1, B2, B6, B12), vitamin C precursors, and niacin. These contribute to skin cell metabolism, antioxidant protection, and brightening activity.
Amino acids — including glutamic acid, aspartic acid, and leucine. Amino acids are the building blocks for protein synthesis and contribute directly to skin hydration and barrier function through Natural Moisturising Factor (NMF) components.
Organic acids — citric acid, malic acid, and succinic acid. These provide gentle exfoliation and improve skin texture over time.
Minerals — zinc, copper, selenium, and magnesium. These support enzymatic processes in skin cell metabolism and provide antioxidant protection.
Polysaccharides — complex sugars that bind water and contribute to the moisture‑retention properties of the filtrate.
Galactomyces Benefits: What It Does for Your Skin
Brightening and evening skin tone. The vitamin C precursors, organic acids, and overall antioxidant activity of the filtrate reduce melanin overproduction and improve skin translucency. The “glass skin” glow associated with galactomyces is real: consistent users describe skin that looks lit from within rather than surface‑shiny. Clinical studies show measurable improvement in skin luminosity at eight weeks.
Pore appearance. The combination of gentle organic acid exfoliation and sebum regulation produces visibly smaller‑looking pores. The exfoliation clears pore openings; the vitamin B complex regulates oil production in sebaceous glands.
Texture refinement. Consistent galactomyces use produces measurably smoother skin texture — the surface irregularities from enlarged pores, minor acne scarring, and uneven skin cell accumulation are progressively reduced over six to eight weeks.
Moisture retention. The polysaccharide and amino acid content contributes to water retention in the stratum corneum — galactomyces essences consistently outperform plain water in barrier hydration measurements, contributing to the plumpness associated with glass skin.
Why Galactomyces Suits UK Skin
Who Should Use Galactomyces
Oily and combination skin benefits most — the sebum regulation and pore refinement mechanisms address the primary concerns of these skin types while the brightening adds clarity and glow.
Dull, uneven, or post‑acne skin — galactomyces is one of the most effective brightening ingredients available without prescription, working through multiple simultaneous mechanisms rather than the single pathway of most brightening actives.
Ageing skin — the texture refinement and moisture retention properties improve fine line appearance over time. The glass skin effect that galactomyces produces is also the most visible anti‑ageing outcome available without retinoids.
Sensitive skin — galactomyces is generally well tolerated and does not cause the irritation associated with dedicated exfoliants or brightening actives. The organic acid content provides very gentle exfoliation that does not trigger sensitivity in most users.
How to Use Galactomyces in a Korean Routine
Galactomyces is used at the essence step — after toning and before serum or moisturiser. It is typically the first essence applied, creating a base of fermented actives that subsequent layers build upon.
Application: Pour a small amount (5–7 drops or a 10 pence coin‑sized amount) into clean palms, press between hands to warm slightly, then press into skin using the patting method. Allow 20–30 seconds to absorb before continuing.
Morning use: Galactomyces applied in the morning before SPF contributes to the dewy, glowing base that Korean skincare is known for.
Evening use: The brightening and texture‑refining mechanisms work overnight — PM application allows the fermented actives to work during the skin’s natural repair cycle.
Frequency: Daily use is safe and recommended for best results. Unlike exfoliating actives, galactomyces does not require rest days.
Best Galactomyces Products Available in the UK
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Reading Galactomyces on Ingredient Labels
- Galactomyces Ferment Filtrate — the most common INCI name for high‑concentration formulations.
- Saccharomyces Ferment Filtrate — the filtrate from Saccharomyces cerevisiae fermentation. Functionally similar; the primary distinction is the specific yeast strain used.
- Position in INCI list: At 50%+, galactomyces will appear within the first two to three ingredients. Products listing it at position eight or lower contain insufficient concentrations for the brightening and texture benefits.
- Pitera™ — SK‑II’s proprietary trademark for their specific galactomyces filtrate. You will not see this name on Korean products but will see equivalent INCI names.
Galactomyces — Frequently Asked Questions
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