Tranexamic Acid

What it is

Tranexamic acid is a synthetic derivative of the amino acid lysine. It was developed and is still used systemically as an anti-fibrinolytic — a drug that reduces bleeding. Its use in topical skincare is a repurposing, and a fairly well-evidenced one.

How it works — and why it is different

Most tone actives do one of two things: inhibit tyrosinase (the enzyme that manufactures melanin), or accelerate the shedding of pigmented surface cells. Tranexamic acid does neither. It works upstream, on the signalling: it inhibits plasmin, which in turn reduces prostaglandin and arachidonic acid release, both of which are signals that activate melanocytes. In plain terms, it intercepts the instruction rather than fighting the output.

The keyword evidence

The exact-match dark spot term carries a supply-demand ratio of 0.35 — more than 22,000 listings competing for under 8,000 searches. Tranexamic acid sits at 89.0, and tranexamic acid serum at 175.5, with roughly 109,000 monthly searches against 622 listings.

The concentration we chose

We publish every percentage because you should be able to compare. In leave-on facial products we use 5%. In the eye area we drop to 3%, because that skin is thinner and more reactive. In the toner pad we use 2%, where contact is briefer. None of these numbers are secret, and none of them are the point. The point is that you can check them.

Where the evidence is thinner

Most topical tranexamic acid research is in melasma, which is a chronic, hormonally influenced condition — not the same thing as a sun spot or a post-acne mark. The mechanism is sound across all three, but the effect sizes are best established in melasma. We use it because it complements the other two mechanisms, not because it is a standalone solution.

Mechanism: upstream signal interception (plasmin → prostaglandin). Not a tyrosinase inhibitor, not an exfoliant. This is why it pairs well with both.