Anti-perspirants act on the eccrine and apocrine sweat glands, reducing sweat secretion. Because there’s less sweat you’ll notice less dampness and less odour. Most anti-perspirants contain the active substances Aluminium Chlorohydrate (ACH) and Aluminium Chloride (AC). AC molecules are smaller and have a lower pH value than the ACH molecules so they can get even deeper into the sweat ducts and keep them closed for longer. Even small quantities of antiperspirant can effectively reduce sweating.