Tranexamic acid

What is tranexamic acid?

Tranexamic acid is a synthetic lysine derivative developed as an antifibrinolytic drug — it inhibits plasminogen activation and is used clinically to reduce bleeding. Its pigmentation use came from the observation that plasmin activity contributes to melanogenesis, particularly in melasma.

How does tranexamic acid work?

Most brightening actives inhibit tyrosinase, the rate-limiting enzyme in melanin synthesis. Tranexamic acid does something different: by interfering with the plasminogen–plasmin pathway it reduces the inflammatory and vascular signalling that drives melanocyte stimulation, particularly UV- and hormone-triggered pigmentation.

That difference is clinically useful, because it means tranexamic acid addresses a pathway that tyrosinase inhibitors do not — which is why it is often combined with them rather than substituted for them, and why it performs relatively well in melasma, where inflammation and vascular components are prominent.

Levels

Topical formulations generally run 2% to 5%. The Youlief DIA Clear Serum uses 5%, which is the top of the usual range and consistent with the concentrations used in clinical comparisons. This is one of the ingredients in the range where the stated level clearly matches the literature.

What does tranexamic acid not do?

It is not a rapid fix; pigmentation work is measured in months. It does not remove pigment already deposited in the epidermis, so it must be paired with sun protection to show any benefit. And topical use is a different proposition from oral tranexamic acid, which carries thrombotic considerations and belongs entirely with a clinician.