How Do Men Make Testosterone?

Hormones & Testicles

Men make 95% of testosterone in their testicles

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Disclaimer: This information isn’t a substitute for professional medical advice, diagnosis, or treatment. You should never rely upon this article for specific medical advice. If you have any questions or concerns, please talk to your doctor.

How Men Make Testosterone

Men make nearly all of their testosterone in the testicles. When your brain senses low testosterone in your blood, it triggers a complicated chain reaction of hormones. This kickstarts testosterone production in the Leydig cells of the testicles. (Testosterone production in women mostly happens in the ovaries). Your adrenal glands also produce a little testosterone.

7 Steps of Testosterone Production

  1. When your brain senses low testosterone levels it makes GnRH hormone
  2. This causes the pituitary gland to makes two more hormones—Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH)
  3. FSH is important for sperm production
  4. LH starts testosterone production in your testicles
  5. Testosterone gets released into your bloodstream
  6. Your brain senses normal testosterone levels and shuts off GnRH, and testosterone production stops
  7. When your brain senses low testosterone levels, it makes more GnRH and the cycle revs up again

Your Testosterone Levels are Always Changing

Think of testosterone production like a brain-to-balls thermostat. When testosterone levels get low, you make hormones that kickstart testosterone production. When you produce “enough” testosterone, your brain flips the hormone switch, and production shuts off. This on/off cycle is part of why testosterone levels are highest in the morning and why testosterone levels vary throughout the day.

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