Bacillus/Folic Acid Ferment Filtrate Extract: What Is It, Cosmetic Uses, Benefits & Side Effects

Curious about this ingredient? In this article we're explaining exactly what it is and why it's used within cosmetic formulations.
Updated on: June 23, 2025
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All information on this page is verified using The Personal Care Products Council's (PCPC) INCI database. Our ingredient analyses are based exclusively on PCPC's technical data to ensure accuracy and reliability.

What Is Bacillus/Folic Acid Ferment Filtrate Extract?

Bacillus/Folic Acid Ferment Filtrate Extract is a skin care ingredient that starts with folic acid rich growth medium and a friendly soil bacterium named Bacillus. During fermentation the bacteria break down the folic acid and other nutrients into smaller, skin friendly compounds. Once the process is complete the liquid is filtered to remove the bacteria, leaving behind a clear extract packed with bio-available vitamins, peptides and amino acids.

Fermented ingredients have been a part of beauty rituals for centuries, but modern interest surged when formulators noticed that these post-biotics increase moisture and boost antioxidant protection without heavy oils or strong preservatives. As a result brands began adding Bacillus/Folic Acid Ferment Filtrate Extract to lightweight moisturizers and soothing treatments in the early 2010s.

Production is straightforward: technicians prepare a tank filled with water, plant sugars and a high dose of folic acid, introduce the Bacillus culture, then keep the mix at an optimal temperature for a few days. After the microbes finish fermenting, the liquid is filtered, concentrated and stabilized for use in cosmetics.

You will most often see this extract in hydrating serums, sheet masks, calming gels, anti-aging lotions, eye creams, essence toners and after-sun treatments where a non greasy boost of moisture and antioxidant support is desired.

Bacillus/Folic Acid Ferment Filtrate Extract’s Cosmetic Benefits/Uses

This multitasking ferment contributes several useful actions in skin care formulas

  • Antioxidant – helps neutralize free radicals created by UV light and pollution which can lead to dullness and early wrinkles
  • Humectant – draws water from the air and deeper skin layers to the surface so the complexion feels plump and comfortable
  • Skin Conditioning – smooths rough texture and supports a healthy skin barrier leaving skin soft and supple

Who Can Use Bacillus/Folic Acid Ferment Filtrate Extract

This gentle ferment is generally suitable for all skin types. Dry and mature complexions appreciate the extra moisture pull while oily or combination skin benefits from weightless hydration that will not clog pores. Sensitive skin often tolerates it well thanks to its soothing peptides, though individual sensitivities can never be ruled out.

The extract is produced by bacteria grown in a plant based medium so it contains no animal derived raw materials, making it appropriate for vegetarians and vegans.

No specific contraindications have been noted for pregnant or breastfeeding women, but this is not medical advice. Anyone expecting or nursing should run new skin care products past a doctor to be on the safe side.

The ingredient does not increase photosensitivity and can be used both morning and night. It also layers nicely under actives like vitamin C and niacinamide without destabilising them.

Potential Side Effects/Adverse Reactions

Reactions to topical Bacillus/Folic Acid Ferment Filtrate Extract vary from person to person. The following lists potential side effects that are unlikely to occur for most users when the ingredient is formulated and used correctly

  • Mild redness or warmth immediately after application
  • Tingling or slight stinging on very compromised skin
  • Itchiness or small bumps in individuals allergic to fermentation by-products
  • Rare cases of contact dermatitis in people with multiple sensitivities

If any of these effects appear or persist discontinue use and consult a healthcare professional or dermatologist

Comedogenic Rating

Rating: 0–1

Bacillus/Folic Acid Ferment Filtrate Extract is water based and contains mostly low-molecular weight peptides, amino acids and vitamins that do not form an occlusive film on skin. There are no heavy oils or waxes that typically block pores, so the risk of congestion is minimal. For this reason it earns a 0–1 on the comedogenic scale.

Suitable for acne-prone or breakout-prone skin because it delivers hydration without adding pore-clogging ingredients.

Formulas that pair the extract with richer emollients could raise the overall comedogenicity, so always check the entire ingredient list of the finished product.

Summary

Bacillus/Folic Acid Ferment Filtrate Extract works as an antioxidant, humectant and skin-conditioning agent. Fermentation breaks folic acid into bio-available compounds that mop up free radicals while small peptides and sugars pull moisture to the surface and smooth rough patches.

Though not as famous as niacinamide or hyaluronic acid, the ferment is quietly gaining fans in K-beauty style essences and lightweight moisturizers for its ability to hydrate without heaviness.

Overall safety profile is strong with low irritation and virtually no pore-clogging potential. Still, skin is personal so perform a patch test when trying any new product containing this ferment to ensure it plays nicely with your unique barrier.

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