Updated: Jun 2

5 min read by Roberta Stringer, Nutrition Magician and Co-Founder of DNA.


[ tes-tos-tuh-rohn ]


Biochemistry. the sex hormone, C19H28O2, secreted by the testes, that stimulates the development of male sex organs, secondary sexual traits, and sperm.

Pharmacology. a commercially prepared form of this compound, originally isolated from bull's testes and now also produced synthetically, used in medicine chiefly for treatment of testosterone deficiency and for certain gynaecological conditions.

What is testosterone and how does it affect your health?

Testosterone is a steroid hormone that plays a key role in optimal hormonal health in men. It’s the primary male sex hormone responsible for the development of male sexual characteristics.

When you see or hear the word testosterone, you might think about sexual vigour, bodybuilders, or your favourite sports heroes. You rarely think about it in terms of your own health. The fact is you are a man because of testosterone!

Our hormonal health journeys start in the womb.

A baby’s sex is determined at conception by his or her genes. Embryos with XY chromosomes become boys, and those with XX chromosomes become girls.

However, throughout pregnancy it’s the exposure to hormones decided by your baby’s genes that affect a baby’s anatomy, physiology and even behaviour from birth.

It’s only when the foetus is around 7 – 8 weeks old that the actual gender specific body parts to develop. In fact, all babies would develop female sex organs if it weren’t for the male hormone testosterone.

Men (and women) understand the important role testosterone (and all hormones) play at puberty, but what happens after then? Why is it that women continue to be informed about their hormones for the rest of the life but men’s relationship with theirs is so disjointed?

That’s a whole other story! One that we will address in another blog.

Age and Testosterone Levels:

Testosterone levels in men rise during puberty, peak around age 20.

It naturally declines after the age of 30, although the prevalence of low T in younger men is increasing due to lifestyle factors.

Over the age of 40, the decline can become rapid and cause negative symptoms more commonly now recognised as Andropause. Also known as male menopause, Testosterone Deficiency (TD) and Hypogonadism.