Nyda is a revolutionary topical treatment for the eradication of head lice. It is very safe and effective. Nyda spreads easily over the scalp and penetrates deeply into the respiratory system of lice, larvae, and eggs replacing the air and killing in the three stages from eggs to adult lice with only one application. Kills the eggs and not only the lice. No resistance. Free of insecticide or pesticide. Suitable for all ages including pregnancy and breastfeeding. Simple and easy to use. Only one application.