4-Hydroxyindole (Standard) is the analytical standard of 4-Hydroxyindole. This product is intended for research and analytical applications. 4-Hydroxyindole is a member of the class of hydroxyindoles that is 1H-indole substituted by a hydroxy group at position 4. 4-Hydroxyindole is an important raw material or intermediate in the synthesis of pharmaceutical products and industrial polymers^[1].