Marine polysaccharides are emerging as some of the most versatile biopolymers in cosmetic science. Extracted mainly from brown and green algae, these high–molecular weight sugars deliver a combination of film-forming, moisture-retaining, and soothing benefits that are difficult to match with purely synthetic systems. Because they support barrier function while improving sensorial properties, marine polysaccharides such as fucoidan, laminarin, and ulvan are becoming core tools for chemists developing next-generation hydrating and barrier-care formulas.
Unlike classic humectants that primarily bind water, marine polysaccharides interact with the skin surface through hydrogen bonding, ionic interactions, and bioadhesion. Consequently, they can create breathable films that help maintain water content in the stratum corneum while also modulating biological pathways related to inflammation and extracellular matrix quality. This article reviews their origin, structure, key benefits, and formulation considerations, focusing on how cosmetic chemists can integrate them into hydrating skincare.
What Are Marine Polysaccharides?
Marine polysaccharides are long-chain carbohydrates produced by macroalgae, microalgae, and certain marine microorganisms. In algae, they serve structural, storage, or protective roles, helping cells tolerate osmotic stress, UV radiation, and fluctuating salinity. From a cosmetic perspective, the most relevant classes include:
- Fucoidan: A sulfated fucose-rich polysaccharide mainly obtained from brown seaweeds such as Fucus vesiculosus and Undaria pinnatifida. It shows notable bioactivity in wound healing and anti-inflammatory models.
- Laminarin: A β-1,3-glucan with occasional β-1,6 branches, also from brown algae. It functions primarily as a storage polysaccharide and displays immunomodulating and antioxidant properties.
- Ulvan: A sulfated heteropolysaccharide from green seaweeds of the genus Ulva, rich in rhamnose, glucuronic acid, and iduronic acid. It has shown moisturizing and film-forming behavior in topical systems.
Because of their sulfate groups and carboxylated sugars, many marine polysaccharides carry a net negative charge. This anionic character enables ionic interactions with cationic species, influences rheology, and contributes to their bioadhesive behavior on skin.
Mechanisms of Hydration and Barrier Support
The hydration performance of marine polysaccharides arises from several overlapping mechanisms that extend beyond simple water binding.
Water Retention and Film Formation
Marine polysaccharides have high affinity for water due to multiple hydroxyl and sulfate groups along their chains. When applied on the skin, they absorb and retain water within a three-dimensional network. Simultaneously, they form thin, cohesive films that slow transepidermal water loss. Studies on fucoidan-based gels, for instance, demonstrate improved stratum corneum hydration and decreased TEWL compared to control formulations.
These films are usually flexible and breathable rather than occlusive. As a result, they provide a comfortable alternative to heavy occlusive agents, especially in lightweight gel serums or fluid emulsions.
Interaction With Stratum Corneum Components
Because of their charge density and chain architecture, marine polysaccharides can interact with keratin, natural moisturizing factors, and intercellular components in the outer epidermis. Such interactions may enhance cohesion and improve surface smoothness. In some models, fucoidan has been shown to stimulate markers associated with barrier recovery and extracellular matrix quality, which indirectly supports hydration by reinforcing structural integrity.
Anti-Inflammatory and Soothing Effects
Inflammation often compromises barrier function and accelerates water loss. Marine polysaccharides like fucoidan and laminarin exhibit anti-inflammatory activity in vitro, including inhibition of pro-inflammatory mediators and modulation of immune cell responses. By calming subclinical inflammation, they help maintain a more resilient barrier, which in turn preserves hydration.
Key Marine Polysaccharides in Hydrating Skincare
Fucoidan
Fucoidan is perhaps the best studied marine polysaccharide in cosmetic science. Its branched, sulfated structure provides both strong water affinity and biological activity. In topical models, fucoidan has been associated with enhanced wound closure, increased collagen synthesis, and reduced UV-induced damage. These properties make it attractive for formulations that combine hydration with anti-aging or soothing claims.
Fucoidan typically contributes a soft, slightly gel-like texture and can improve the feel of aqueous gels and oil-in-water emulsions. Because of its anionic charge, formulators must consider compatibility with cationic conditioning polymers or preservatives to avoid unwanted complexes.
Laminarin
Laminarin, a β-glucan-like polysaccharide, offers structural similarity to terrestrial β-glucans while retaining unique marine characteristics. It shows antioxidant and immunomodulating properties and can support skin comfort in compromised conditions.
In hydrating products, laminarin helps improve perceived plumpness and resilience. It can also be combined with classic humectants such as glycerin or hyaluronic acid, as it contributes film-forming benefits while humectants draw water into the stratum corneum. This combination leads to longer-lasting hydration with a refined texture.
Ulvan
Ulvan from green algae has a distinct sugar composition that includes rhamnose and uronic acids. This profile contributes to both hydrating and antioxidant behavior. Several studies describe ulvan’s ability to form viscoelastic gels and to protect against oxidative stress in biological systems.
In cosmetic systems, ulvan can be used to build lightweight gel networks or to adjust rheology while adding a marketing story around green algae. Its presence helps maintain uniform water distribution on the skin surface and may contribute to a subtle tightening sensation without stiffness.
Formulation Design With Marine Polysaccharides
Successful use of marine polysaccharides in hydrating skincare requires balancing their functional benefits with practical formulation constraints such as solubility, viscosity, and compatibility.
Solubility and Processing
Most marine polysaccharides are supplied as dry powders or concentrated solutions. They usually require gradual hydration under high-shear mixing in the aqueous phase. Because they may swell or form lumps if added too quickly, pre-dispersing in a portion of water or mixing with a humectant can improve handling.
Temperature also matters. Some grades dissolve more readily at elevated temperatures, while others degrade if exposed to prolonged high heat. Supplier guidelines for hydration temperature and mixing time should therefore be followed closely.
Viscosity Management
Marine polysaccharides contribute to viscosity even at relatively low inclusion levels. This is beneficial when designing gel serums or light creams, yet it can become challenging if overused. To avoid excessive thickness, formulators typically start within a range of 0.1 to 1 percent active polymer, adjusting based on the specific molecular weight and target texture.
Combining marine polysaccharides with synthetic or other natural rheology modifiers can provide more precise control over yield value, shear-thinning behavior, and sensory attributes. For instance, fucoidan may be layered over an acrylic polymer or natural gum to fine tune slip and after-feel.
Compatibility and Stability
The anionic nature of many marine polysaccharides means they may form complexes with cationic polymers or certain preservatives. These interactions can lead to haze, precipitation, or viscosity shifts. Therefore, stability screening should include combinations with conditioning agents, quaternary ammonium compounds, and cationic surfactants, especially in hair or body care systems.
From a microbiological standpoint, polysaccharides can serve as nutrient sources for microbes if preservation is insufficient. Robust preservative systems validated by challenge testing are essential, particularly in high-water activity gels and toners.
Positioning Marine Polysaccharides in Product Concepts
Because marine polysaccharides provide both functional and marketing advantages, they can be positioned in several ways within a brand portfolio.
- Barrier-repair hydrating serums: Combining fucoidan or laminarin with ceramide-supporting actives and humectants delivers robust hydration while promoting resilience.
- Urban defense moisturizers: Marine polysaccharides can be framed as shield-forming biopolymers that help the skin cope with urban stressors such as pollution and dry indoor air.
- Post-procedure soothing products: Their film-forming and calming properties make them attractive for products designed to support recovery after aesthetic procedures, provided that the overall formula is aligned with professional guidance.
- Overnight masks and sleeping packs: The gentle film formed by marine polysaccharides supports slow-release hydration throughout the night without heavy occlusion.
Because the same molecules appear in multiple product types, consistent communication of their mechanism and origin helps reinforce credibility and build a coherent algae-based narrative across the line.
Sustainability and Sourcing Considerations
Marine-derived ingredients must be evaluated not only for efficacy but also for environmental impact. Responsible sourcing of seaweed and algae is critical. Many suppliers now emphasize controlled cultivation, certified harvesting zones, and traceability systems. Such measures aim to avoid overharvesting and to maintain biodiversity in coastal ecosystems.
Fermentation and bioreactor-based production pathways are also emerging. These technologies can generate marine-like polysaccharides with reduced dependency on wild biomass, while enabling more consistent quality. For brands that prioritize sustainability, collaboration with suppliers who document eco-certifications, life-cycle assessments, and regulatory compliance provides additional value.
Regulatory and Safety Aspects
Most marine polysaccharides used in cosmetics have a long history of safe use in food, pharmaceuticals, or topical applications. Nevertheless, each extract should be evaluated individually, since composition can vary by species, harvest location, and extraction method. Safety assessment usually includes irritation testing, sensitization studies, and in some cases, evaluation of heavy metals or contaminants.
From a regulatory standpoint, proper INCI listing and adherence to regional cosmetic regulations are essential. Because many marine polysaccharides are complex mixtures, documentation from suppliers on extraction processes, purity, and residual solvent levels provides important support for product safety files.
Strategic Takeaways for Cosmetic Chemists
Marine polysaccharides offer a powerful combination of hydration, barrier support, and sensory enhancement. For chemists and product developers, they open the door to gentle yet effective moisturization strategies that align with consumer interest in marine biotechnology and natural biopolymers.
- Use fucoidan, laminarin, and ulvan to create lightweight hydrating films that improve water retention without heavy occlusion.
- Leverage their anti-inflammatory and antioxidant potential when designing products for sensitive or environmentally stressed skin.
- Consider rheology, charge interactions, and microbial stability early in development to avoid surprises during scale-up.
- Connect with suppliers that document sustainable harvesting and manufacturing practices, reinforcing responsible blue biotechnology positioning.
By integrating marine polysaccharides into modern formulations, brands can deliver hydration benefits that feel sophisticated on the skin while telling a compelling scientific story grounded in marine biology.
