Average testosterone levels in men have fallen by 54 percent globally between 1972 and 2019, according to research presented at the European Society of Human Reproduction and Embryology annual meeting in London.
The study, reported by The Guardian, compiled data from six longitudinal tracking projects involving 118,593 men across Israel, the United States, Brazil, Finland, and Denmark.
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Findings show the hormonal decline began accelerating significantly after the year 2000, pointing to a broader systemic problem rather than an isolated health phenomenon.
Experts Warn of Reproductive Health Crisis
“I think that we have a major crisis in male reproductive health and it's currently not given enough attention,” said Prof Hagai Levine of the Hebrew University-Hadassah Braun School of Public Health and Community Medicine in Israel.
Levine’s team previously documented significant drops in historical sperm counts, which drew international attention to male reproductive trends.
“We saw an over 50% decline in total testosterone over this time period,” Levine said, adding that the trend reflects more than a 1 percent decline each year.
“This is not a fluke, this is not a statistical error. It's very strong trend.”
The underlying causes remain debated, with scientists examining modern lifestyles, metabolic issues, and shifting environmental conditions as potential drivers.
Rising rates of diabetes and obesity globally are heavily linked to lower hormonal metrics, as testosterone and body chemistry have a complex relationship.
“Reproductive health is a very important signal of general health,” Levine said, noting that public health approaches must change to mitigate external risks.
