Laminaria Saccharina Extract

This ingredient comes from the brown algae called Laminaria saccharina (aka Saccharina latissima or sugar kelp).

What is it made up of?

• alginates and laminarin which are big water loving sugar molecules that form a light film on the skin. This gives you some moisturizing and skin protecting action
• phlorotannins, or polyphenols that brown algae make which bring antioxidant and soothing properties to the party

Now the honest part:

The manufacturer sells this as an anti-seborrhoeic active that calms down oil production and refines the look of pores. This comes from supplier data and not published clinical trials so there is no randomized controlled trial on this ingredient for oiliness, acne, or anything else.

What does exist is one in-vitro study where the extract reduced melanin production in cultured cells + bumped up gluthatione (kind of promising for brightening, but petri dishes are not the same as skin).

The safety profile is the strongest part of this ingredient: human repeat insult patch tests on 50 people came back with zero sensitization. Patch testing at 8% and 16% also showed no irritation at all with only slight irritation when applied neat at 100%

Typical use levels are around 1-3% of the trade material.

Acne

You'll see algae listed as a 5/5 on a lot of pore-clogging charts and that number doesn't come from anywhere; it's not in the original rabbit-ear studies that most comedogenic ratings trace back to.

The reasoning behind the reputation is that seaweed is high in iodine and iodine can trigger acne-like breakouts when eaten. This traces back to a 1976 letter in Archives of Dermatology describing two women whose breakouts cleared after they stopped taking high-dose kelp supplements orally.

And the reaction of these two women wasn't clogged pores at all: it was an iodine-triggered pustular rash. Later research found normal dietary iodine doesn't meaningfully affect acne either and nobody has shown topical algae delivers enough iodine to matter.

What we do have is dozens of brown and red algae ingredients found to be non-irritating and non-sensitizing, and a handful of studies that found algae compounds may actually help acne.

However, plenty of people do report breaking out from algae-containing products. Skin is individual and it's worth avoiding if yours has reacted to algae before.