What Is Thalassiosira Pseudonana Extract?
Thalassiosira Pseudonana Extract is a marine derived ingredient obtained from the microalga Thalassiosira pseudonana, a type of diatom that lives in cold ocean waters. The alga’s cells contain polysaccharides, amino acids, minerals, protective pigments such as carotenoids and a natural silica shell that helps it withstand harsh sea conditions. Interest in its protective qualities led marine biotechnologists to explore it for skincare during the early 2000s, and it has been appearing in cosmetic formulas ever since.
To produce the extract, the microalga is grown in large seawater tanks under controlled light and nutrient conditions. Once the culture reaches the right density, the algae are harvested, rinsed and mechanically disrupted to release their inner compounds. The bioactive solution is then filtered, purified and concentrated before being preserved for use in cosmetics.
You will most often see Thalassiosira Pseudonana Extract in daily moisturizers, anti pollution serums, anti aging creams, sheet masks and after sun products, where it supports the skin’s natural barrier against environmental stress.
Thalassiosira Pseudonana Extract’s Cosmetic Benefits/Uses
This ingredient is valued for one main performance benefit.
Skin protecting: The mix of marine polysaccharides and antioxidants helps reinforce the skin’s surface, forming a breathable film that limits moisture loss while shielding against pollutants and oxidative stress. Regular use may leave skin feeling smoother, calmer and more resilient to everyday environmental damage.
Who Can Use Thalassiosira Pseudonana Extract
This microalgae extract is generally suitable for all skin types, including dry, oily, combination and sensitive skin, because it is lightweight and non occlusive. People with a known allergy to algae or sea-derived ingredients should avoid it, as they could experience irritation.
The extract is plant based and harvested from microscopic algae, so it is considered appropriate for both vegans and vegetarians provided the finished formula contains no animal-derived additives.
There are no specific restrictions for pregnant or breastfeeding women, yet this is not medical advice and anyone who is expecting or nursing should run new skincare products past a healthcare professional to be on the safe side.
The ingredient is not known to cause photosensitivity, meaning it does not make skin more prone to sunburn, though daily sunscreen is still recommended for overall skin health.
Potential Side Effects/Adverse Reactions
Side effects and reactions to topical Thalassiosira Pseudonana Extract can vary from person to person. The points below list potential issues that may occur, yet they remain uncommon when the ingredient is properly formulated and used as directed.
- Mild skin redness or flushing
- Transient stinging or burning sensation
- Localized itching
- Allergic contact dermatitis in individuals sensitive to algae
- Rare cases of rash or hives
If you notice any of these reactions, stop using the product and consult a healthcare professional for guidance.
Comedogenic Rating
Rating: 1 out of 5. Thalassiosira Pseudonana Extract is water based and rich in light polysaccharides rather than heavy oils or waxes, so it rarely blocks pores. A rating of 1 reflects a very low chance of clogging while acknowledging that any ingredient can potentially cause issues in a small number of users.
Suitable for acne-prone skin, as the extract is non greasy and does not leave a residue that traps oil or debris.
Because formulas differ, the overall pore-clogging potential of a finished product will also depend on the other ingredients and the texture of the base.
Summary
Thalassiosira Pseudonana Extract acts mainly as a skin-protecting agent. Its mix of marine sugars, minerals and antioxidants forms a thin flexible film on the surface, helps slow water loss and neutralizes stress from pollution or UV exposure, leaving skin calm and resilient.
The extract is still a niche addition compared with big-name actives like hyaluronic acid yet it is popping up more often in daily moisturizers, anti-pollution serums and after-sun gels as brands look for novel marine ingredients.
Safety studies and real-world use show the extract is well tolerated for most skin types, with only rare reports of irritation in people sensitive to algae. As with any new product, patch test first to make sure your skin is happy.