Zinc oxide
The Unna’s Boot itself is a compression dressing, usually made of cotton, that contains zinc oxide paste. The zinc oxide paste in the Unna’s Boot helps ease skin irritation and keeps the area moist. The zinc promotes healing within wound sites, making it useful for burns and ulcers. Zinc oxide paste is superior to gelatins used in other dressings, because it does not harden or cake. Some Unna Boots also contain calamine lotion and glycerin.