Aspergillus/Rice Germ Ferment Extract Filtrate

This ingredient is the filtered liquid you get from fermenting rice germ with Aspergillus (a type of koji mold).

It is an emollient with skin conditioning properties.

Fermenting the rice adds some interesting benefits: the microbes break down the starches, proteins, and lipids into smaller, more skin-available molecules like amino acids, peptides, organic acids, and antioxidants like ferulic acid.

Lab research backs up several of these claims as well. A 2024 in vitro study on red rice fermented with Aspergillus found the ferment boosted markers tied to anti-aging, moisturizing, barrier repair, skin brightening, and inhibited melanin synthesis.

A 2025 study on fermented rice bran extract showed it increased collagen and elastin synthesis in cell and 3D skin models.

Earlier work on Aspergillus-fermented rice grains also measured real antioxidant and brightening activity.

One honest caveat worth keeping in mind is that most of this evidence comes from cell and lab models, and not large human clinical trials.

So for now, it's worth thinking of this ingredient as promising and well-supported rather than clinically proven on faces.

For those worried about the Aspergillus part of the ingredient: Aspergillus is the same food grade koji used in soy sauce and sake.

Published concentration data is sparse, but comparable rice/ferment filtrates are typically used somewhere in the 0.5-5% range. Suppliers also recommend 0.5-4% for leave-on products.