Updated on
08th Dec 2025
Seaweed skincare benefits: why spas and salons are embracing marine ingredients
Seaweed might be dismissed by some as little more than coastal detritus or a dinner plate delicacy, but in the spa and skincare industry, it’s one of the most potent natural ingredients on the menu.
Whether used in facials, wraps or targeted homecare, this marine botanical is experiencing a resurgence in popularity, becoming associated with regeneration, hydration and holistic healing.
What are the skin benefits of seaweed in skincare?
“Seaweed is an incredible marine plant,” explains Malcolm Macrae, scientist and co-founder of skincare brand Ishga. “It has been proven to regenerate skin cells, support collagen, contain detoxifying effects, supply a potent source of antioxidants, promote hyaluronic acid production and is a powerful hydrator for all skin types.
“It’s also an extremely resilient plant, and these properties transfer to our skin to deliver protection and healing.”
Seaweed’s strength lies in the fact that it’s not a single ingredient, but rather a category of diverse species, each with its own skin-boosting profile.
Macrae points to three seaweed varieties that can be harvested from the Hebridean coastline, each offering targeted skincare benefits.
“Fucus serratus is known to contain high levels of antioxidant polyphenols which produce anti-ageing and hydrating effects. It’s excellent at repairing skin.
“Ascophyllum nodosum, on the other hand, balances the natural moisture barrier and acts as an anti-inflammatory while gently exfoliating.
“Fucus vesiculosus improves skin condition and reduces inflammation, releasing beneficial minerals like iodine and polysaccharides.”
These seaweeds are packed with bioactive compounds – not just antioxidants, but also essential minerals, polysaccharides like alginates and fucoidans, amino acids and skin vitamins A, C and E.
Together, they address everything from fine lines to dehydration, sensitivity, acne and conditions like eczema and psoriasis.
It’s a profile that’s difficult to match with any one land-based plant, and therapists are taking note.
A trainer’s perspective on seaweed’s versatility
Leanne Roche, national trainer at Matis Paris, agrees that seaweed offers wide-ranging, multi-faceted benefits.
“Seaweed can be used to aid in the treatment of a variety of different skin concerns and combines well with other ingredients,” she explains.
“The numerous different varieties of seaweed could contain vitamins, amino acids and micronutrients. This allows you to increase microcirculation, oxygenation of cells, moisturising and protection of the skin.”
She adds that seaweed is significantly more nutrient dense than many land botanicals: “Seaweed is significantly more nutrient-dense than land-based botanicals, offering a richer, more complete profile of minerals, vitamins, and unique bioactive compounds.
“Brown algae, for example, is known for its antioxidant properties, natural sources of 12 vitamins including B12, C, E, K and beta-carotene, 18 amino acids and 42 trace elements.”
How spa therapists use seaweed in facial and body treatments
For Katrina Sutherland, owner of The Country Spa in Lybster, Scotland, and a long-time Repêchage ambassador, seaweed’s wide-ranging benefits were what first drew her to marine ingredients. At her spa in the Scottish Highlands, seaweed is central to both facial and body treatments.
“At The Country Spa, we offer a comprehensive selection of facials, plus hand and foot treatments, body exfoliations and seaweed wraps to target cellulite,” she says. “Seaweed products have been chosen for our salon as it is a natural and sustainable ingredient which delivers impressive nourishing and healing for the skin’s tissues.”
Roche echoes its usefulness within a wide treatment remit, noting that it supports multiple skin types and concerns: “Seaweed is a great ingredient for lots of different skin concerns and is suitable for most skin types. By choosing a product containing seaweed, you will help your client to achieve more resilient, hydrated and radiant skin.”
She highlights its applicability across skin profiles: “All skin types can benefit from marine extracts because of the rich nutrient profile and natural humectant properties.
“For antiageing, the amino acids and peptides found in seaweed help to promote collagen and elastin production. In an oily skin it has a natural detoxifying effect to help draw out excess oil from the skin and reduce breakouts.”
Both professionals emphasise the impact these ingredients can have on confidence and wellbeing, particularly for clients dealing with sensitivity, redness, dryness or breakouts.
Understanding different seaweed species and extracts
Roche notes that species selection matters significantly when it comes to clinical outcomes:
“The various varieties of seaweed offer different skincare benefits. Irish seaweed comes from the North Atlantic and has emollient, softening and moisturising properties. It forms a protective film on the skin, helping to prevent moisture loss. Red algae has soothing and protective properties, helping to soothe sensitive skin, reduce redness and strengthen the skin barrier.”
How seaweed skincare products are made: extraction and formulation
Delivering results like these starts with careful extraction. “Our seaweed extract is the cornerstone of our range,” explains Macrae.
“It’s extracted directly into Hebridean spring water using a low-temperature extraction process, which protects the beneficial compounds and enzymes. Our process has been independently tested and is rich in polyphenols for healthy skin.”
Formulation isn’t without challenges – early on, Ishga had to overcome the strong marine scent of raw seaweed without losing its therapeutic properties.
“After much testing and trialling, we developed the low-temperature extraction process that’s at the heart of our range, which allows minimal odour while retaining all the incredible benefits,” he says.
Stability and potency are also key concerns, but Macrae points out that marine extracts are now widely recognised for their scientific efficacy.
“Recent scientific advancements have highlighted marine ingredients as potent allies in skincare, offering solutions for hydration, anti-ageing and inflammation management,” he says.
Ongoing research is exploring how seaweed could help with chronic skin conditions such as acne, psoriasis and atopic dermatitis – with early results looking promising.
Why seaweed is a sustainable skincare ingredient
In an industry increasingly focused on sustainability, seaweed is a natural frontrunner.
“As a marine plant, seaweed does not need soil, fresh water or fertiliser to grow; it is completely self-sufficient, nutrient-dense and grows rapidly year-round,” explains Macrae, adding that responsible harvesting methods are also important: “ensure it is cut properly to allow for quick, natural regeneration.”
Roche adds, “Seaweed farming is a low-impact process that requires no fertilisers, pesticides, or feed. The seaweed farms can also act as artificial reefs, providing habitats for diverse marine life and increasing biodiversity.”
Ishga’s seaweed harvesting is certified by the Biodynamic Association, with hand-harvesting methods and a rotating shoreline schedule to protect biodiversity and encourage natural regrowth.
Macrae says, “There’s definitely growing enthusiasm among consumers and skincare therapists for marine-based, sustainable products. People are increasingly mindful of their skincare choices, actively seeking solutions that are effective, natural and eco-friendly.”
Sutherland agrees: “Clients today want to know where ingredients come from, how they are harvested and what impact they have. Seaweed ticks all the boxes; it’s traceable, sustainable and offers real results.”
Choosing and recommending seaweed-based skincare
Therapists are increasingly expected to understand ingredient lists and assess product quality. According to Roche, quality starts with origins.
She says, “The quality of the seaweed can be determined by multiple factors such as sourcing location, harvesting methods and processing techniques. Brands should be transparent about their methods when asked.”
Contraindications to consider
While seaweed is very safe, Roche emphasises a few important cautions: “Those with thyroid conditions should be cautious due to the iodine content. Open wounds should also be avoided and those with any marine allergies (seafood, shellfish).”
Combining seaweed skincare with scientific actives for better results
Despite its natural credentials, seaweed isn’t at odds with modern science. In fact, it often works in harmony with synthetic actives.
“Seaweed-based ingredients are excellent for holistic, gentle skincare, ideal for barrier support, hydration and antioxidant protection,” says Macrae.
“Synthetic actives are better suited for treating specific concerns quickly and efficiently. Many modern formulations now combine both for optimal results.”
Roche explains, “Seaweed is great combined with hyaluronic acid as it protects the skin’s moisture levels, while hyaluronic acid acts as a moisture magnet. As seaweed is known to stimulate natural collagen production and inhibit the enzymes that break the existing collagen down, it is amazing paired with marine collagen.”
She adds that seaweed works well alongside peptides, ceramides and even acids. “Marine-derived peptides act as messengers to help maintain the skin’s youthful appearance. The fatty acids in some seaweed complement the accompanying ceramides, and they can also help to mitigate any potential irritation caused by acids when formulated correctly.”
At The Country Spa, this translates to seaweed being at the heart of personalised, science-informed spa protocols. “Seaweed products and protocols provide a relaxing but very effective treatment, which is endorsed by years of scientific research and training,” says Sutherland.
“Clients are confident in our suggestions when we can explain the effects that the various products will have on the skin’s function.”
The future of seaweed in professional skincare
Roche believes interest in marine ingredients will continue to grow, driven by consumer values as well as results.
“She says, As consumers are becoming more environmentally aware, I think sustainable ingredients that still give incredible results will be more sought after. Using seaweed provides a natural and vegan alternative to some animal-derived ingredients, such as collagen, and supports a growing awareness of eco-friendly and renewable resources within the beauty industry.”
From soothing dryness and rosacea to supporting teenage skin health, seaweed continues to show itself as a versatile, sustainable and effective tool in the therapist’s kit, whether used alone or as part of a carefully constructed, multi-active formula.
