The world of seaweed
Fucus vesiculosus: Ocean’s Antioxidant Shield
Fucus vesiculosus, a brown macroalga from the genus Fucus, is widely distributed in temperate and cold coastal regions and is recognised as a rich source of bioactive compounds with diverse biochemical functions that contribute to multiple skin-related benefits. Scientific studies highlight its potency as an antioxidant, capable of neutralising reactive oxygen species (ROS) and mitigating oxidative stress in skin cells.
The polyphenolic content of Fucus vesiculosus includes phenolic acids such as gallic acid, gentisic acid, chlorogenic acid, vanillic acid, caffeic acid, and protocatechuic acid, along with other compounds reported in literature, including p-coumaric acid, catechin, epicatechin, rutin, and ferulic acid. Of particular note are phlorotannins, a unique class of polyphenols found only in brown seaweeds, which demonstrate strong free radical-scavenging capacity and are considered major contributors to the antioxidant potential of this species (Wang et al., 2012; Getachew et al., 2012).
In addition to polyphenols, Fucus vesiculosus contains antioxidant pigments such as chlorophyll-a, pheophytin-a, β-carotene, and zeaxanthin. Fucoxanthin, a marine-exclusive carotenoid characteristic of brown algae, exhibits potent antioxidant properties and helps protect cellular structures from oxidative damage (Quintana et al., 2024). The antioxidant activity of Fucus vesiculosus is attributed to its ability to scavenge free radicals, chelate pro-oxidant metal ions, and inhibit lipid peroxidation, thereby supporting skin barrier integrity, reducing oxidative damage, and helping protect against premature ageing.
Saccharina japonica – Ocean’s Hydration Reservoir
Saccharina japonica — previously known as Laminaria japonica — is a prized brown seaweed cultivated in cold, nutrient-rich marine environments where it thrives under the dynamic forces of tides and changing waters. This resilience is closely linked to its biochemical composition: the seaweed is naturally rich in peptides, amino acids, and unique polysaccharides that work together to support skin hydration, moisture balance, and overall vitality.
Scientific studies over the years have explored these naturally occurring polysaccharides in Saccharina japonica and highlighted their remarkable humectant properties — the ability to attract, bind, and retain water molecules. This water-binding capacity is one of the reasons why the seaweed is able to withstand dehydration stress in its natural habitat. Interestingly, in carefully controlled laboratory conditions, some polysaccharides from Saccharina japonica have been reported to show strong water-retention capacity, in some cases higher than that of hyaluronic acid — a benchmark compound that is widely regarded as one of the gold standards in modern skincare hydration.
Hydration in Saccharina japonica is not driven by a single compound, but rather by a synergy of its key components. Peptides and amino acids contribute to maintaining skin’s natural moisture balance, while the diverse family of polysaccharides provides additional humectant strength. Among these polysaccharides, alginate has drawn particular scientific interest. Unique to brown algae and absent in terrestrial plants, alginate is often highlighted in scientific literature for its exceptional ability to interact with water. In nature, alginate allows the seaweed’s cells to swell, remain flexible, and preserve hydration even under challenging marine conditions. This same characteristic, when translated to skincare, is often discussed in research as a notable natural mechanism for moisture retention. Scientific literature has reported that sodium alginate is capable of absorbing up to 200–300 times its own weight in water, demonstrating an extraordinary capacity for retaining and holding moisture.
It is insights from such studies that guided Kelp kiss to select Saccharina japonica as one of its key hydration-supporting ingredients, drawing inspiration from the depths of the ocean in developing modern skincare.
Porphyra umbilicalis: Ocean’s Natural Sunscreen
Seaweeds like Porphyra umbilicalis have evolved photoadaptive mechanisms to protect themselves, including antioxidant activity and the production of UV-absorbing secondary metabolites. This red algae thrives in the intertidal zone, where it is naturally exposed to high levels of sunlight and environmental stress, making it a resilient and potent ingredient for skin protection.
A key component of its defense is the presence of mycosporine-like amino acids (MAAs) — water-soluble molecules that absorb ultraviolet light in the 309–360 nm range. MAAs act as natural UV filters, efficiently dissipating absorbed radiation while supporting antioxidant defense. Porphyra umbilicalis is rich in MAAs such as palythine, shinorine, and porphyra-334, known for their strong UVA/UVB-absorbing capacity and remarkable stability, making them highly relevant for modern sunscreen formulations.
In addition, the algae contains sulfated polysaccharides like porphyran, a hot-water-soluble component of its cell wall. These molecules offer antioxidant and skin-soothing properties, further enhancing skin resilience against daily environmental stress.
Together, the combination of MAAs and polysaccharides in Porphyra umbilicalis provides natural photoprotection and antioxidant care for the skin.