It shows that 4-Butylresorcinol (4-n-butylresorcinol) significantly inhibits melanin synthesis in a concentration-dependent manner. In addition, it is also found to inhibit the activity of tyrosinase, the rate-limiting melanogenic enzyme. 4-Butylresorcinol does not induce ERK, Akt activation, or MITF degradation, and has no effect on cAMP response element binding protein (CREB) phosphorylation, which stimulates MITF expression. 4-Butylresorcinol strongly reduces tyrosinase activity in a cell-free system. Moreover, 4-Butylresorcinol shows an additive effect in combination with hinokitiol, which reduces MITF expression.