“Testosterone levels have been declining at 1% per year since 1982.”
Dr Shana Swan, Reproductive epidemiologist, Professor of Environmental Medicine and Public Health - Countdown (2021)

Men’s innate hormone balance is key to their masculine potential. Testosterone is a key hormone in men’s health, driving both physical performance and mental clarity. It supports muscle growth, bone density, fertility, and recovery while also influencing energy, motivation, and cognitive function.

The emerging science shows a significant decline in average testosterone levels over time, independent of age. The scientists sounding the alarm link the collapse of testosterone levels to men’s modern lifestyle and environmental chemicals called Endocrine Disrupting Chemicals.

Testosterone decline graph Testosterone decline graph

Various studies have documented the decline in men's testosterone levels over recent decades. They demonstrate a testosterone decline of approximately 1% per year, independent of age and of BMI, suggesting that environmental chemicals and lifestyle factors are driving a broader hormonal shift across the male population.

Graph data from ‘Gleicher, N., Shachar, Y., & Hod, M. (2020). Secular trends in testosterone: Findings from a large state-mandated health organization. Reproductive Biology and Endocrinology, 18, 23.

“People are recognising we have a reproductive health crisis… I am not saying other factors aren’t involved.  But, I am saying chemicals play a major causal role.” Dr Shanna Helen Swan. The Guardian, March 2021. Reproductive epidemiologist, Professor of Environmental Medicine and Public Health 

The steep decline in average testosterone levels has produced growing scrutiny of prevalent endocrine disrupting chemicals. Endocrine disrupting chemicals interact and interfere with endocrine system receptors. Endocrine disrupting chemicals are found in personal care products, cosmetics, food and packaging, cookware, as well as many other consumer products. These chemicals can block binding of natural hormones to receptors and alter normal hormone function.