TESTOSTERONE LEVELS HAVE BEEN DECLINING AT 1% PER YEAR SINCE 1982.

DR SHANA SWAN, REPRODUCTIVE EPIDEMIOLOGIST, PROFESSOR OF ENVIRONMENTAL MEDICINE AND PUBLIC HEALTH - COUNTDOWN (2020)

Testosterone is essential to male health, regulating energy, muscle mass, mood, cognitive function, and reproductive health. It's the hormone that defines masculine vitality.

Yet emerging science reveals a troubling trend: testosterone levels in men have been declining for decades, with environmental factors increasingly implicated as a primary cause.

AVERAGE TESTOSTERONE LEVELS (ng/dL)

580 570 560 550 540 530 520 510 500
568
553
523
520
2006-09 2010-12 2013-15 2016-19

THE EVIDENCE

Multiple peer-reviewed studies have documented this decline. Research published in the Journal of Clinical Endocrinology & Metabolism found that average testosterone levels in American men dropped by roughly 1% per year between 1987 and 2004.

A 2020 meta-analysis confirmed these findings, showing the trend has continued and potentially accelerated in recent years.

Source: Travison et al., Journal of Clinical Endocrinology & Metabolism, 2007; NHANES data 2006-2019