What is Testosterone?

It’s time to take a look at testosterone. This sex hormone is typically associated with male biology, but in reality, it also plays an important role in female bodies too! In this post, we’re going to look at testosterone’s function, where it's made, and its roles in both female and male biology.

Illustration of the testosterone hormone

Testosterone’s function

 What does testosterone do? Well, testosterone’s function differs between men and women, although it is closely linked to libido in both sexes. Testosterone in men is one of the major sex hormones, whereas in women it’s still important, but more so in relation to the female sex hormones that regulate the menstrual cycle

Where is testosterone produced?

In men, testosterone is produced in the testes, and, in women, it’s produced in the ovaries. Small amounts of testosterone are also produced in the adrenal glands in both sexes, while the production of hormones is regulated by the pituitary gland in the brain.  

Testosterone in men

Testosterone is more prevalent in males. It’s responsible for many of the changes boys experience in puberty such as growth spurts, deepening of the voice, growth of pubic hair, and enlargement of the penis. In adult males, testosterone is key in sperm production. It also helps with the production of red blood cells and keeps muscles and bones strong. Testosterone levels in men are usually higher in the morning, hence morning erections, and decline throughout the day. Hormone levels also continue to dip as men age. 

What impacts testosterone production in males?

Testosterone production can be affected by the use of anabolic steroids that are often taken to quickly increase muscle mass. It has become a significant cause of male infertility, although many men are unaware of this side effect. Anabolic steroids increase testosterone production in the body - this blocks the production of testosterone in the testicles themselves, which is essential for sperm production. If taken at a high enough dose and for long enough, it can permanently reduce fertility, while sperm production may return to normal as much as one year if the damage is not permanent.

Testosterone in women  

In women, testosterone is directly linked to the menstrual cycle, in that it is essential for the production of the main female sex hormone, estrogen. Testosterone is also useful for the growth and repair of reproductive tissues. In some cases, high levels of testosterone in the blood can be an indication of polycystic ovary syndrome (PCOS) in women, and may also be accompanied by symptoms such as acne and increased body and/or facial hair. If you have concerns about PCOS, or are experiencing changes to your cycle, you should speak with your healthcare professional.

Tracking changes throughout your cycle

The shifts in hormones that happen throughout our cycle, may be subtle but they are definitely noticeable once you start getting to know the pattern of your cycle. While you might feel capable of anything around ovulation, once estrogen levels dip and progesterone levels rise towards the end of your cycle, you’re more likely to feel the lethargy and irritable symptoms of PMS. This is all down to hormones, and those of us on hormonal birth control can go long periods of time without experiencing these changes through the cycle. 

Here at Natural Cycles, we offer a hormone-free birth control method that helps you learn the science of your cycle, so you can prevent pregnancy on your own terms. Our app also makes it easy to track the pain, emotions and other symptoms you might experience over the course of your cycle. This is a really useful way to get to know your body better, all while preventing pregnancy hormone-free. Why not find out if Natural Cycles could work for you?

Discover Natural Cycles today

Jen on the roof terrace at Natural Cycles headquarters.

Written By

Jennifer Gray

A writer with a passion for women’s health, Jennifer Gray has years of experience writing about various reproductive health topics including birth control, planning pregnancy, women’s anatomy, and so much more.

Jack in a suit and tie holding a microphone and giving a presentation.

Scientifically Reviewed

Jack Pearson

With 10 years of experience working in the field of fertility, Jack Pearson is Natural Cycles’ in-house expert. As Medical Affairs Manager, he dedicates his time to conducting groundbreaking research and educating healthcare professionals.

Keep Reading: Related Articles