Lactobacillus/Phragmites Communis Root Extract Ferment Filtrate: 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: July 1, 2025
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We verify all information on this page using publicly available nomenclature standards from The Personal Care Products Council (PCPC), the European Commission's CosIng database and documentation provided directly by ingredient manufacturers. Our analysis is based on technical data from these sources to ensure accuracy and reliability.

What Is Lactobacillus/Phragmites Communis Root Extract Ferment Filtrate?

Lactobacillus/Phragmites Communis Root Extract Ferment Filtrate is produced when the roots of Phragmites communis, better known as common reed, are fermented with beneficial Lactobacillus bacteria. The process breaks down the root’s tough plant matter and releases a mix of small peptides, amino acids, sugars, lactic acid and antioxidants that are easily absorbed by skin. Fermented botanicals gained popularity through Korean beauty formulations in the early 2000s, and this particular ferment caught the eye of cosmetic chemists for its soothing and barrier-support qualities.

To make it, freshly harvested reed roots are cleaned, chopped and placed in a controlled vessel with a Lactobacillus culture. Over several days the bacteria convert plant compounds into skin-friendly molecules while lowering pH, which helps preserve the mixture. The liquid is then filtered to remove solids, yielding a clear ferment filtrate that is added to finished products.

You will commonly spot this ingredient in hydrating sheet masks, calming moisturizers, barrier-repair creams, sensitive skin toners, lightweight serums, after-sun gels and anti-aging products that aim to strengthen the skin’s natural defenses.

Lactobacillus/Phragmites Communis Root Extract Ferment Filtrate’s Cosmetic Benefits/Uses

This ferment brings a one-two punch of conditioning and protection to topical formulas.

  • Skin conditioning: The mix of amino acids, sugars and lactic acid draws moisture to the surface layers, smooths rough texture and leaves skin feeling soft and supple
  • Skin protecting: Antioxidants and barrier-support molecules help defend against everyday environmental stress, reduce visible redness and support a healthy moisture barrier

Who Can Use Lactobacillus/Phragmites Communis Root Extract Ferment Filtrate

This ferment filtrate is generally well tolerated by all skin types including dry, oily, combination and especially sensitive skin thanks to its soothing and barrier supportive profile. Very oily or acne prone users do not normally experience clogged pores because the ingredient is lightweight and water based

The ferment is made from plant roots and Lactobacillus bacteria so it contains no animal derived material and is suitable for both vegans and vegetarians. Manufacturing practices vary, so cruelty free status depends on the finished brand’s policies

No specific warnings exist for pregnancy or breastfeeding, and the ingredient’s gentle nature makes it a low risk choice. That said this information is not medical advice and anyone who is pregnant or nursing should show the full product ingredient list to a qualified healthcare provider before use

The filtrate does not increase photosensitivity so it can be used day or night without heightening the chance of sunburn. It layers well with common actives such as niacinamide, hyaluronic acid and ceramides and does not interfere with sunscreen efficacy

Potential Side Effects/Adverse Reactions

Responses to topical Lactobacillus/Phragmites Communis Root Extract Ferment Filtrate differ from person to person. The issues listed below are only potential outcomes and are unlikely for most users when the ingredient is properly formulated and preserved

  • Mild stinging or warmth may occur on freshly exfoliated or compromised skin
  • Transient redness in very reactive skin types can appear shortly after application typically fading within minutes
  • Allergic contact dermatitis is rare but possible in individuals sensitive to certain plant proteins or fermentation byproducts
  • Eye irritation if the product accidentally gets into the eyes, especially with higher concentration formulas like essences

If any persistent burning, swelling or rash develops discontinue use immediately and consult a healthcare professional

Comedogenic Rating

Rating: 0 / 5. Lactobacillus/Phragmites Communis Root Extract Ferment Filtrate is water based, oil free and made up of small molecules like amino acids and sugars that rinse off or absorb quickly rather than sitting in pores. It does not leave an occlusive film, so it poses virtually no risk of clogging. Because of this, people who break out easily can usually use products featuring this ferment without worry. If the finished formula also contains heavier oils or waxes, those other ingredients, not the ferment itself, would be the factors to check.

Summary

Lactobacillus/Phragmites Communis Root Extract Ferment Filtrate conditions skin by drawing in water with its natural sugars, amino acids and gentle lactic acid then shields the surface with antioxidants that support the moisture barrier. The K-beauty boom put ferments like this on the map, and while it is not as mainstream as hyaluronic acid it appears in a growing number of calming serums, masks and creams aimed at sensitive skin.

Overall it is considered low risk, vegan friendly and non comedogenic, with side effects limited to rare irritation in very reactive users. As with any new skincare step, a small patch test on the inner arm or jawline is a smart move before slathering it on your face.

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