5-Hydroxyindole is primarily utilized in biochemical research as a precursor or intermediate in the synthesis of more complex compounds, particularly those related to neurotransmitters. It plays a significant role in studies involving serotonin pathways, as it is structurally similar to serotonin, a key neurotransmitter in the human body. Researchers use it to investigate the effects of serotonin on mood, appetite, and sleep, as well as its role in neurological disorders. Additionally, 5-Hydroxyindole is employed in the development of pharmaceuticals targeting conditions like depression, anxiety, and migraines. Its applications also extend to organic synthesis, where it serves as a building block for creating indole derivatives with potential biological activity.