Galactomyces is probably the most used ingredient in Korea that no one talks about in France. Present in essences, toners, and serums from almost all major K-Beauty brands, it is responsible for that luminous, even complexion that many associate with Korean skin. Specifically, it's a yeast ferment that concentrates highly bioavailable active ingredients, capable of penetrating the epidermis without irritation.
In this article, you will understand what galactomyces is exactly, why Korean skincare makes it a pillar of its formulations, and how to effectively integrate it into your routine based on your skin type.
Are you looking directly for a galactomyces essence or serum? Our selection is formulated with effective concentrations, without denatured alcohol. (see Korean essences)
What is galactomyces? 🔬
Galactomyces ferment filtrate is a filtrate obtained by fermenting Galactomyces, a unicellular fungus from the yeast family. Its history in cosmetics is directly linked to Japanese sake production: researchers observed that artisans who handled koji (the ferment used in sake production) had exceptionally smooth and luminous hands despite intense physical work.
This observation triggered years of research into the properties of this ferment. Today, galactomyces ferment filtrate is one of the most documented active ingredients in Asian cosmetics, present at concentrations of up to 95-99% in some Korean formulas.
What distinguishes it from other active ingredients is its composition: the fermentation process breaks down complex molecules into smaller fragments, making them bioavailable, meaning they can cross the skin barrier effortlessly. This filtrate contains amino acids, B vitamins, minerals, enzymes, and low molecular weight peptides.
What are the benefits of galactomyces for the skin? ✨
Galactomyces acts simultaneously on several skin functions, which explains why it is difficult to replace with a single other active ingredient.
Radiance and skin tone evening. This is the most visible and fastest effect. Galactomyces inhibits tyrosinase, the enzyme involved in melanin production. By specifically reducing this production, it gradually lightens dark spots, post-acne marks, and uneven skin tone. A study published in the Journal of Cosmetic Dermatology showed a significant reduction in pigmentation spots after 12 weeks of regular use of a product formulated with galactomyces ferment filtrate.
Hydration and strengthening of the skin barrier. The amino acids and sugars present in the filtrate act as natural humectants: they attract water into the upper layers of the epidermis and retain it. Simultaneously, lipids resulting from fermentation strengthen the skin's hydrolipidic film. The concrete result: more supple, less reactive skin that loses less water throughout the day.
Texture and pores. By regulating sebum production and promoting cell renewal, galactomyces helps refine skin texture over time. Some users observe a visible reduction in the appearance of pores after 4 to 8 weeks of use. This is not a mechanical tightening effect, but a consequence of improved hydration and accelerated epidermal renewal.
Gentle anti-aging action. Peptides and amino acids from fermentation stimulate collagen and elastin synthesis in the dermis. The effect is gradual and cumulative, making it an anti-aging active suitable for young skin that wants to prevent, as well as mature skin that wants to correct.
Expert tip: many confuse galactomyces and niacinamide because both act on skin tone. They don't target the same things. Galactomyces acts upstream on melanin production and barrier quality. Niacinamide blocks melanin transfer to keratinocytes. Both are complementary and well tolerated together.
Galactomyces, bifida ferment, ferment filtrate: what are the differences? 🧪
The world of ferments in Korean cosmetics can be confusing. Here are the essential distinctions.
| INCI Ingredient | Source organism | Main action | Typical texture |
|---|---|---|---|
| Galactomyces Ferment Filtrate | Galactomyces yeast | Radiance, uniformity, hydration | Essences, toners, light serums |
| Bifida Ferment Lysate | Bifida bacteria | Microbiome, barrier, anti-reactivity | Creams, soothing serums |
| Saccharomyces Ferment Filtrate | Saccharomyces yeast | Hydration, suppleness, antioxidant | Creams, masks |
| Lactobacillus Ferment | Lactic acid bacteria | Microbiome, skin pH, gentle radiance | Toners, gentle essences |
Galactomyces stands out for its potential for very high concentration (up to 99% of the formula) and its broad spectrum of action: it is simultaneously hydrating, brightening, and restructuring. Other ferments are often more targeted at a single mechanism.
Who is galactomyces for and who is it less for? 🎯
The good news: galactomyces is one of the best-tolerated active ingredients in Korean cosmetics. Its fermentation process degrades potentially irritating molecules, making the final filtrate very low in allergens.
Particularly suitable for:
- Dull, tired skin with an uneven complexion
- Skin with post-acne marks or light to moderate dark spots
- Combination to oily skin that wants to hydrate without feeling heavy
- Minimalist routines: a good galactomyces product can replace several steps
- Skin in transition (stopping birth control, post-pregnancy) with recent complexion irregularities
Use with caution if:
- You have a known allergy to yeast or fungi (rare, but worth checking)
- Your skin is very dry and dehydrated: galactomyces alone is not enough; an occlusive agent must be combined to retain hydration
On sensitive or rosacea-prone skin, galactomyces is generally well-tolerated, but introducing the product gradually is still recommended, as with any new active ingredient.
How to use galactomyces in your Korean routine? 📋
Galactomyces is primarily found in three formats: essences, toners, and serums. Their position in the routine varies slightly depending on the format.
Galactomyces essence or toner (e.g., Mixsoon Galactomyces Ferment Essence, COSRX Galactomyces 95 Tone Balancing Essence): applies after cleansing, on slightly damp skin, before other serums. Pat gently rather than rubbing — galactomyces is absorbed in seconds.
Concentrated galactomyces serum (e.g., Some By Mi Galactomyces Pure Vitamin C Glow Serum, iUNIK Rose Galactomyces Synergy Serum): applies after toner, before cream. If the serum combines galactomyces and vitamin C, apply it in the morning, always followed by an SPF.
What concentration to choose? Formulas with 70 to 99% galactomyces ferment filtrate are the most effective. Below 50%, the active ingredient is present but in insufficient quantity for a visible effect. Check the INCI list: if "Galactomyces Ferment Filtrate" appears in the first 3 ingredients, the concentration is significant.
Preferred combinations:
- Galactomyces + niacinamide: excellent synergy for even skin tone
- Galactomyces + hyaluronic acid: multi-layer hydration, luminous texture
- Galactomyces + SPF in the morning: protects the results obtained on the complexion
Compatibility with acids (AHA/BHA): galactomyces is compatible with low-concentration chemical exfoliants. When using strong acids, stagger applications (galactomyces in the morning, acids in the evening) to avoid overloading the skin barrier.
Results on radiance and texture are visible within 3 to 4 weeks. Skin tone evening and spot reduction take between 8 and 12 weeks of regular use. Consistency trumps applied quantity.
The best Korean galactomyces products available in France 🛍
The French market offers some solid references. Here are the most relevant ones based on skin profile and budget.
Mixsoon Galactomyces Ferment Essence. Purified formula with very high concentration of galactomyces ferment filtrate, fragrance-free, denatured alcohol-free. Format: light essence. Ideal for beginners with the ingredient or for sensitive skin that wants a risk-free formula.
COSRX Galactomyces 95 Tone Balancing Essence. The entry-level reference. 95% galactomyces ferment filtrate, very light watery texture, almost immediate absorption. Suitable for all skin types. First visible effect on radiance in 2 to 3 weeks.
iUNIK Rose Galactomyces Synergy Serum. Combines galactomyces and rose water for a simultaneous soothing and brightening effect. Serum format, slightly more nourishing than essences. Suitable for combination to dry skin looking for both hydration and radiance.
Some By Mi Galactomyces Pure Vitamin C Glow Serum. Combines galactomyces and stabilized vitamin C for enhanced anti-spot and antioxidant action. Reserved for skin that already tolerates vitamin C. Use exclusively in the morning, followed by SPF.
You can consult our selection of Korean serums to find the format that matches your current routine.
Galactomyces deserves its reputation with real potential for radiance and even skin tone that few active ingredients offer with such broad tolerability. If you only add one ingredient to your Korean routine this season, it's probably this one.
To identify which galactomyces product corresponds to your specific skin type, the Holy Skin skin diagnostic gives you a personalized recommendation in 2 minutes.
