health
Where Has All the Testosterone Gone?
Levels of the hormone have dropped in the past half century—but no one knows exactly why.
TL;DR
- Average testosterone levels in men have declined by approximately 20-50 percent over the past half century.
- Potential causes for the decline include environmental endocrine-disrupting chemicals and lifestyle changes such as obesity and reduced physical activity.
- The decline is observed even in normal-weight men, suggesting factors beyond obesity are at play.
- Low testosterone can affect mood, sexual function, energy, muscle mass, heart health, bone health, and fertility.
- Widespread testing for low testosterone, as proposed by the Trump administration for the military, is considered unnecessary and potentially harmful by many medical experts.
- The long-term implications of this hormonal shift and its potential impact on human biology are still unknown.