Deltamethrin (DEL) and other synthetic repellents like N,N‐diethyl benzamide (DEB), N,N‐diethyl phenylacetamide (DEPA), and N,N‐diethyl meta toluamide (DEET) are widely used due their high efficacy against mosquitoes. We evaluated the safe dose on exposure to insecticide and insect repellent individually and in combination in Wistar rats. Rats were administrated with individual chemicals DEL, DEB, DEPA, and DEET and in combination of DEL along DEB, DEPA, and DEET. The reduced glutathione and its detoxifying enzymes were significantly increased in DEL treated rats. Serotonin, dopamine, and noradrenaline were increased in DEL alone and its combination groups. Histopathology revealed that DEL and along with other insect repellants can cause lung toxicities. This study suggests that DEL in combination with other insect repellents showed antagonistic effect against oxidative stress, and there was no significant toxicological effect in the combination groups. The insect repellents with DEL cause less toxic effect and is safe for use.