Ingredient review
Ceratoneis Closterium Extract
INCI: CERATONEIS CLOSTERIUM EXTRACT
A gentle marine extract that may help hydrate and calm the skin, but research is still early.
In plain English
Ceratoneis Closterium Extract comes from a type of microalgae found in the ocean. In skincare, it's used to help add moisture to the skin and reduce redness or irritation. Think of it as a gentle, watery ingredient that supports your skin's natural barrier without feeling heavy or greasy.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is still emerging, so marketing claims deserve extra caution.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- natural
- Evidence
- emerging
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Ceratoneis Closterium Extract is generally a lower-concern ingredient when the full formula suits your skin.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging Ceratoneis Closterium Extract.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
emergingThe ingredient may be promising, but claims should be treated more cautiously.
What it is
A natural extract derived from the marine diatom Ceratoneis closterium, a type of single-celled algae. It is rich in polysaccharides and other compounds that can help retain moisture.
How it works
It forms a thin, hydrating film on the skin's surface, helping to lock in moisture and temporarily soothe minor irritation. The polysaccharides in the extract attract water molecules, supporting the skin's natural hydration levels.
Pros
Gentle hydration
Provides a light layer of moisture without clogging pores, making it suitable for most skin types, including oily and combination skin.
Soothing potential
Early research suggests it may help calm minor redness or irritation, which can be beneficial for sensitive skin.
Cons and cautions
Limited evidence
Most studies are lab-based or very small; there is not yet strong clinical evidence for its effectiveness on human skin.
Rare allergy risk
As a marine-derived ingredient, it could trigger an allergic reaction in people with specific sensitivities to algae or seafood.
Best for
- People with dry or dehydrated skin
- Those looking for a gentle, natural hydrating ingredient
Use caution if
- Individuals with known allergies to algae or marine products
Usage tips
Safety summary
Ceratoneis Closterium Extract is considered safe for topical use with a low risk of irritation. As with any new ingredient, patch testing is recommended for those with sensitive skin or allergies.
Research notes
Current research is preliminary, focusing on the extract's hydrating and soothing properties in lab settings. More human studies are needed to confirm its benefits.
Common label clues
- Typical concentration
- 0.5% to 2%
- Regulatory status
- Generally recognized as safe for cosmetic use in the US and EU, with no specific restrictions.
- Common uses
- Serums, Moisturizers, Face masks
- Environmental note
- Harvested from cultivated microalgae, which has a lower environmental impact than wild harvesting of marine organisms.
Good to know
- This ingredient is often found in 'blue beauty' or ocean-inspired product lines.
- It is considered a sustainable ingredient when harvested responsibly.
Common questions
What is Ceratoneis Closterium Extract in beauty products?
Ceratoneis Closterium Extract comes from a type of microalgae found in the ocean. In skincare, it's used to help add moisture to the skin and reduce redness or irritation. Think of it as a gentle, watery ingredient that supports your skin's natural barrier without feeling heavy or greasy.
What does Ceratoneis Closterium Extract do in a beauty product?
It forms a thin, hydrating film on the skin's surface, helping to lock in moisture and temporarily soothe minor irritation. The polysaccharides in the extract attract water molecules, supporting the skin's natural hydration levels.
Is Ceratoneis Closterium Extract safe for most people?
Ceratoneis Closterium Extract is considered safe for topical use with a low risk of irritation. As with any new ingredient, patch testing is recommended for those with sensitive skin or allergies.
Who should be careful with Ceratoneis Closterium Extract?
Individuals with known allergies to algae or marine products
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.