Hearing Extract is a nutrient-dense marine botanical, scientifically identified as Codium fragile, that functions as a potent humectant and anti-inflammatory agent. This green algal extract excels at strengthening the skin barrier while providing deep, long-lasting hydration similar to high-molecular-weight polysaccharides.
- INCI Name:
- Codium Fragile Extract
- Chemical/Scientific Name:
- Codium fragile (Suringar) Hariot Extract
- Common Aliases:
- Hearing Extract (Common K-Beauty translation), Sea Staghorn Extract, Green Sea Fingers, Dead Man’s Fingers Extract.
| Category: | Active Substances |
| Source Origin: | Marine (Green Algae) |
| Comedogenic Rating: | 0 |
| Primary Industries: | Cosmeceuticals, Personal Care, Oral Care |
| Solubility: | Water-soluble |
At a Glance: Properties & Effects
| Hydration/Moisture: | |
| Soothing/Calming: | |
| Barrier Repair: | |
| Irritation Risk: |
- Primary Benefits: Intensively hydrates the stratum corneum, reduces pro-inflammatory cytokine expression, and stimulates filaggrin production to reinforce the skin’s physical barrier.
- Potential Risks: Extremely low risk of irritation; generally suitable for sensitive and reactive skin types.
Biological Action & Cosmetic Profile
Marine biology research classifies Codium fragile as a “siphonous” green seaweed rich in sulfated polysaccharides, particularly galactans and arabinogalactans. These complex carbohydrates act as superior humectants by creating a non-occlusive, moisture-binding film on the skin surface. Unlike simple humectants such as Glycerin, these algal polysaccharides offer sustained hydration by resisting rapid evaporation and maintaining osmotic balance within the skin cells.
Cellular studies demonstrate that this extract significantly upregulates the expression of essential barrier proteins, including filaggrin, involucrin, and loricrin. By reinforcing these structural components, the ingredient reduces trans-epidermal water loss (TEWL) and enhances the skin’s resilience against environmental stressors. Its anti-inflammatory profile is equally substantive, as it has been shown to inhibit nitric oxide (NO) production and suppress the release of tumor necrosis factor-alpha (TNF-α) and various interleukins in stimulated keratinocytes.
The antioxidant capacity of the extract stems from its high content of phenolic compounds and chlorophyll derivatives. These molecules neutralize reactive oxygen species (ROS) generated by UV exposure and pollution, thereby mitigating oxidative damage to dermal collagen and elastin fibers. In specialized formulations, such as those targeting the eye contour, the extract may also assist in improving microcirculation and reducing the appearance of puffiness by stabilizing capillary permeability.
Broader Applications & Origins
The term “Hearing Extract” is a literal linguistic translation of the Korean word for this seaweed, cheong-gak (청각), which also denotes the sense of hearing. While the nomenclature may appear unusual in English-speaking markets, the ingredient is a staple in East Asian marine-based skincare. Beyond topical cosmetics, the alga is utilized in oral care for its ability to inhibit biofilm formation on tooth surfaces and is traditionally consumed for its nutritional density, which includes high levels of vitamin A, vitamin C, and essential minerals.
Routine Integration
- Synergies: This ingredient pairs exceptionally well with Sodium Hyaluronate for multi-level hydration and Panthenol for enhanced soothing. It is frequently found in formulas containing Aqua and Butylene Glycol to facilitate rapid absorption.
- Conflicts: There are no known chemical incompatibilities with common cosmetic actives.
Clinical Consensus & Safety
Dermatological assessments and the Cosmetic Ingredient Review (CIR) Expert Panel categorize algal extracts like Codium fragile as safe for use in personal care products. Peer-reviewed studies in journals such as the Journal of Microbiology and Biotechnology highlight its potential as a therapeutic adjunct for inflammatory conditions like atopic dermatitis due to its low immunogenicity. Current regulatory frameworks in the EU (CosIng) and the USA permit its use without specific concentration restrictions, provided the extract is free from heavy metal contaminants common to marine sources.
Why is it called “Hearing Extract” in my skincare?
The name is a direct translation from the Korean name for the seaweed (cheong-gak). Scientifically, it is Codium fragile, a green alga used for its skin-soothing and hydrating properties.
Is it suitable for acne-prone skin?
Yes. This extract has a comedogenic rating of 0, meaning it does not clog pores. Its anti-inflammatory properties can also help calm the redness associated with active breakouts.
How does it compare to Hyaluronic Acid?
While both are humectants, Hearing Extract provides additional benefits like antioxidant protection and skin barrier repair through the stimulation of structural proteins, whereas hyaluronic acid focuses primarily on water retention.