What it actually does: interrupts the signalling between UV-stressed skin cells and pigment cells - upstream of where vitamin C and arbutin work. Originally a medication for bleeding; dermatology borrowed it after noticing patients’ melasma improving.
Who it’s for: melasma (the symmetrical patches often triggered by hormones and heat - extremely common here and famously stubborn), plus general dark marks on sensitive skin.
How to use it: 2–5% topically, morning and/or night. Combines well with niacinamide and arbutin - melasma especially demands the team approach, plus fanatical sun protection, because heat and light are its fuel.
Honest expectations: eight to twelve weeks. Melasma managed, not cured - it recurs if protection lapses. Severe cases: dermatologist.
The BYOUT Library is educational content, not personalised medical advice. For persistent or severe skin concerns, a dermatologist beats any article, including ours.