Skin Conditioning

Laminaria Japonica Extract

INCI: LAMINARIA JAPONICA EXTRACT

Reviewed by Emma · Last updated 14 Aug 2026

Also known as: Laminaria Japonica Extract

A seaweed extract that supports skin hydration and helps protect against environmental stress

Best For Skin Types

All, Dry, Sensitive, Mature

Addresses

Dryness, Hydration, Sensitivity, Barrier repair

Effective Concentrations

Up to 10%

Usage Frequency

Daily

What Is Laminaria Japonica Extract?

Laminaria japonica extract is derived from a species of brown kelp harvested from East Asian waters. It contains naturally occurring polysaccharides and other bioactive compounds that have been studied for their effects on skin hydration and protection.

In skincare formulations, this ingredient functions primarily as a skin protectant, helping to maintain moisture levels and support the skin's natural barrier function.

How It Works

The polysaccharides in Laminaria japonica extract work as humectants, drawing moisture into the outer layers of the skin and helping it remain hydrated. The extract also appears to strengthen the skin's lipid barrier, which reduces water loss through the skin surface.

At a cellular level, preliminary research suggests the extract may modulate inflammatory pathways activated by UV exposure, potentially helping to minimise photodamage responses. It may also influence the balance between collagen-building and collagen-degrading enzymes in the skin.

Clinical Evidence & References

Clinical research on hydration shows that a 10% concentration of Laminaria japonica extract increased skin hydration by approximately 14% and reduced transepidermal water loss by around 20% in human testing. These effects were measured over an 8-hour period, with the strongest activity observed at the 2-hour mark.

Animal studies have demonstrated that the extract may support collagen maintenance and help suppress inflammatory markers associated with skin ageing and UV damage. However, these results are from laboratory and animal studies; long-term human efficacy data remains limited. The ingredient appears to be well-tolerated, though further research on diverse skin types would strengthen the evidence base.

How to Use

Laminaria japonica extract is typically found in hydrating serums, moisturisers, and barrier-support products. Apply to clean skin as part of your regular routine. It pairs well with other humectants and barrier-supporting ingredients, and can be used morning and evening as part of a consistent skincare regimen.

Safety & Precautions

Laminaria japonica extract is generally considered well-tolerated in cosmetic formulations. Those with known sensitivities to seaweed or iodine should exercise caution, as seaweed extracts may contain trace iodine.

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