Spirulina Extract
INCI · Spirulina Platensis Extract · also Arthrospira Platensis, Blue-Green Algae, Phycocyanin
How it works
Spirulina is a cyanobacterium rather than a plant or a true algae, and the extract carries a mixture: phycocyanin — the blue pigment-protein that gives it its colour — along with amino acids, carotenoids, B vitamins and minerals. Phycocyanin is the component with the most interesting activity, showing antioxidant and anti-inflammatory effects in laboratory work, including inhibition of COX-2.
On skin the practical contribution is that of a supporting antioxidant with some soothing action, plus the humectant behaviour of the amino acid fraction. It is not a targeted active and no single mechanism is being relied on.
The evidence
The literature on spirulina is substantial and overwhelmingly oral — supplementation studies on lipids, blood pressure, allergic rhinitis. None of that transfers to an extract in a serum, and the size of that body of work is routinely used to imply topical evidence that does not exist.
Topically there are small studies and in vitro results supporting antioxidant activity and some anti-ageing claims. That is enough to justify including it in an antioxidant blend and not enough to make it the reason to buy a product.
Suitability
- All skin types; particularly unobjectionable for sensitive skin
- Best as part of an antioxidant mix rather than as a standalone step
- No specific group needs to avoid it beyond general botanical allergy
Concentration
Low, and the colour is why. Phycocyanin is intensely blue-green, so a formula either uses a small amount, uses a decolourised fraction, or commits to being a coloured product. A pale cream claiming spirulina is telling you the amount is small.
Conflicts & combinations
No conflicts. Two practical notes: phycocyanin is heat- and light-sensitive, so the same packaging logic that applies to vitamin C applies here; and spirulina material can be contaminated with microcystins if harvested from open water, which is a supplier-quality issue rather than an ingredient one, and one reason cosmetic-grade sourcing is not interchangeable with food-grade.
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- Max safe
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Does spirulina do anything for skin?
Phycocyanin has antioxidant and anti-inflammatory activity in laboratory work. Topically it is a reasonable supporting antioxidant, not a targeted active.
Does the spirulina supplement research apply?
No. That literature is oral — lipids, blood pressure, allergic rhinitis — and none of it transfers to an extract applied to skin.
Why is there so little spirulina in products?
Phycocyanin is intensely blue-green. A formula either uses a small amount, a decolourised fraction, or commits to being visibly coloured.
Is spirulina safe in skincare?
Yes, and it is well tolerated. Beyond general botanical allergy there is no specific group that needs to avoid it.
What are microcystins?
Toxins that can contaminate spirulina harvested from open water. It is a supplier-quality issue, and a reason cosmetic-grade sourcing is not interchangeable with food-grade.