Research shows men's testosterone down 54% over 50 years

A new analysis of long-term data indicates that average testosterone levels in men have fallen by more than 50 percent over the past five decades, a trend researchers describe as a strong signal of a broader crisis in male reproductive and general health. The findings were presented on July 7, 2026, at the annual meeting of the European Society of Human Reproduction and Embryology in London.

The research, led by Professor Hagai Levine of the Hebrew University-Hadassah Braun School of Public Health in Israel, synthesized data from six longitudinal studies conducted between 1972 and 2019. The analysis included information from 118,593 men across five countries: Israel, the United States, Brazil, Finland, and Denmark. The results showed an average decline of 54 percent in total testosterone levels over that period, equating to a drop of more than one percent per year. The pace of decline appears to have accelerated particularly after the year 2000.

Testosterone is a crucial hormone for men, regulating not only sperm production and libido but also muscle mass, bone density, mood, energy levels, and overall metabolism. A sustained population-wide decline, therefore, has implications...