Ebio3 is a selective potassium ion channel (KCNQ2) inhibitor with an IC50 of 1.2 nM. It binds to the KCNQ2 channel via its hydrophobic tail, causing the inward movement of the S6 helix, which results in the closure of the internal gate. The inhibitory effect of Ebio3 is equally effective on pathogenic KCNQ2 mutants, such as R75C and I238L, reducing their outward current by approximately 80%. Ebio3 holds potential for research in neurological disorders like epilepsy.