How performance drugs work

Many performance-enhancing drugs use the hormonal system (also known as the endocrine system), and they’re not without their risks. Here’s how that system works.

Still curious? Read more: Drugs in sport

Have you ever wanted to be stronger, faster, or more energetic? Plenty of athletes have, and some take drugs in an effort to chemically enhance their bodies. Many of those drugs use the hormonal system (also known as the endocrine system), and they're not without their risks. Here's how that system works.

  1. Hormones are produced naturally throughout the body by glands.
  2. The hormones enter the bloodstream and are transported around the body.
  3. When hormones encounter cells with receptors that fit, it binds to that cell.
  4. This triggers chemical changes to the cell, thus causing changes in bodily functions.

The glands

  • Pineal gland
  • Hypothalamus
  • Pituitary gland
  • Thyroid gland
  • Parathyroid gland
  • Thymus
  • Adrenal glands
  • Pancreas
  • Kidneys
  • Ovaries (female)
  • Testes (male)

Each gland produces hormones (such as testosterone, oxytocin, and growth hormone) which affect the body in many different ways.

Affected bodily functions

  • Blood pressure
  • Metabolism
  • Growth rates
  • Appetite
  • Cell production
  • Arousal
  • Heart function
  • Liver function
  • Brain function
  • Temperature
  • Alertness
  • Gastric activity
  • Body fat
  • Pain
  • And plenty more

Performance drugs mimic hormones

Like hormones, these chemicals bind to target cells and trigger changes in bodily functions. So if you want to enhance your body, you take a drug that mimics a hormone which produces the effect you want (like anabolic steroids, which mimic testosterone, which bind to target cells, resulting in increased muscle size)... right?

Side effects in a complex system

Unfortunately, this hormonal system is so complex that you cannot seek one effect without a range of other possible effects, many of which can be unwanted or dangerous. Here are some of the side effects of common performance drugs.

Anabolic steroids

Why they're used
  • To increase muscle size
  • To increase muscle strength
  • To decrease body fat
  • To decrease recovery time
Other effects
  • More body hair
  • Decreased voice pitch
  • Increased blood pressure
  • Acne
  • Liver problems
  • Decreased fertility
  • Increased chance of kidney failure
  • Increased chance of heart disease
  • Aggression
  • Baldness


Why it's used
  • To increase bone strength
  • To increase red blood cells
  • To increase heart function
  • To increase energy
  • To increase bone growth
Other effects
  • Abnormal growths
  • Heart and organ failure
  • Decreased life expectancy
  • Diabetes


Why it's used
  • To increase red blood cells
  • To increase blood cell regulation
  • To increase aerobic capability
Other effects
  • Blood clotting
  • Heart attacks
  • Stroke