Most underrated active for skin lightening? Tranexamic acid (TXA) is a skincare active that can be used to treat hyperpigmentation and melasma, and some say it's safer and more effective than other brightening agents like retinol, hydroquinone, and vitamin C. TXA works by inhibiting tyrosinase, the enzyme that produces darkening pigment, and by interfering with melanin production. It can also help calm the skin and restore the skin barrier. | Dr Lim Ing Kien