The Chemical Composition of Human Sweat

Elements in Perspiration

Beads of moisture on man's neck and back, close-up
Scott Kleinman/The Image Bank/Getty Images

As you might imagine, human perspiration is mainly water. Have you ever wondered what else is in sweat? Here's a look at the chemical composition of perspiration and the factors that affect it.

Why Do People Sweat?

The main reason people perspire is so evaporation of water can cool the body. Therefore, it makes sense that the main component of perspiration is water. However, perspiration also plays a role in excretion of toxins and waste products. Sweat is chemically similar to plasma, but certain components are selectively retained or excreted.

Variations in Perspiration Chemical Composition

The chemical composition of perspiration varies between individuals and also depends on what they have been eating and drinking, why they are sweating, how long they have been perspiring, and several other factors.

General Composition

Perspiration consists of water, minerals, lactate, and urea. On average, the mineral composition is:

Trace metals that the body excretes in sweat include:

  • Zinc (0.4 milligrams/liter)
  • Copper (0.3–0.8 mg/l)
  • Iron (1 mg/l)
  • Chromium (0.1 mg/l)
  • Nickel (0.05 mg/l)
  • Lead (0.05 mg/l)