Can You Mix Glycolic Acid and Tranexamic Acid?

Why

This is another prevent-and-clear pairing, but tranexamic acid works through an unusual route. Rather than only blocking the pigment enzyme like arbutin or kojic acid, tranexamic acid interferes with the plasmin pathway and the messengers passed from keratinocytes to pigment cells, which calms the overproduction of melanin that drives melasma and heat- or inflammation-triggered darkening. Glycolic acid contributes nothing to that signalling; it is an AHA that removes the dead, pigment-laden cells sitting at the surface, so the discolouration already present clears faster while tranexamic acid slows what is coming. That division of labour is why they are used together for difficult, recurring pigmentation. Tranexamic acid is generally well tolerated and not itself an exfoliant, so it does not add sting. The caution, as with any glycolic pairing, is that the acid lowers surface pH, raises UV sensitivity and can irritate, and irritation can worsen melasma. Steady, gentle use plus disciplined sun protection beats aggressive layering every time with pigment.

How to combine them

Tranexamic acid can be used morning and night because it is mild, so an easy structure is tranexamic acid twice daily with glycolic acid slotted into the evening a few nights a week. Morning: cleanse, apply tranexamic acid, moisturise, then SPF 30+, which is critical for any pigment treatment. Evening: cleanse, on acid nights apply glycolic to dry skin then moisturiser; on other nights apply tranexamic acid again. If layering in one routine, apply glycolic first, let it settle a few minutes, then tranexamic acid. Start the glycolic at twice weekly and build up only if comfortable. Because melasma is chronic and easily reignited by sun and heat, treat sunscreen and shade as part of the active routine, not an optional extra.