Men’s Testosterone Levels Have Halved Over the Past 50 Years - Here's WhyTestosterone Decline Explained: Causes, Limits, and Risks

A striking new estimate has intensified a long-running debate about male reproductive health. The headline is simple, but the evidence behind it requires careful interpretation.

The decline appears across several populations, yet researchers have not identified one decisive cause. The strongest explanations, remaining uncertainties and medical implications are set out below.