Men's testosterone levels have plummeted by 54% over the past 50 years, according to new research presented at the European Society of Human Reproduction and Embryology in London on July 7. The study, which analyzed data from 118,593 individuals, found a decline equivalent to more than 1% per year from 1972 to 2019, a trend researchers described as 'strong'.
Health implications and expert warnings
Dr Jeff Foster, author of the testosterone handbook Optimal, called the statistic 'staggering' and 'concerning for several reasons'. 'We need testosterone to stay healthy throughout our entire lives,' he told Metro. Low testosterone is linked to increased risks of heart attack, diabetes, mental health problems, social and work difficulties, and mortality. 'If your testosterone is low, you simply have a greater risk of dying sooner,' Dr Foster added. 'This is a really important statistic we cannot ignore.'
The findings have prompted major concerns for men's reproductive health. Dr Foster agreed with researchers who dubbed the decline a 'crisis'. 'It's safe to say the impact on men's health isn't going to be good,' he said. 'Worst case, this could lead to a reduction in fertility, a reduction in lifespan, and healthspan for men with a reduced level of testosterone.'
Contributing factors: obesity, climate, and chemicals
Four suspected factors are driving the decline. Obesity and diabetes are major contributors: excess body fat increases the conversion of testosterone into oestrogen. In 2024, 66% of UK adults over 16 were overweight or obese, including 70% of men, according to the NHS. Additionally, 6 million people in the UK have diabetes, 90% with type 2.
Global heating also plays a role. Earth's average temperature is roughly 3.2°C above pre-industrial levels, according to the Met Office. Perhaps more surprising is the impact of endocrine-disrupting chemicals found in household items like non-stick cookware, personal care products, and canned foods. 'A lot of the blame has been put down to environmental contaminants, things like microplastics or endocrine disruptors, and there is no doubt these play a role in reducing male testosterone production,' Dr Foster said. 'But we don't know how much these environmental contaminants actually impact overall testosterone levels.'
Hidden health costs and NHS strain
Beyond visible symptoms like fatigue and reduced libido, Dr Foster warned of 'things you cannot see'. Testosterone is essential for metabolism, cardiovascular health, and neurological function. 'If you start to reduce this, over time, the overall health of the male population will go down. That is catastrophic,' he said. 'A significant drop in testosterone is going to lead to a much poorer quality of life. You will be less happy. You will be less healthy. Your physical, your mental, and your sexual health will be worse, and your overall risk of multiple medical problems will go up.' This will place increasing strain on the already stretched NHS.
How to boost testosterone naturally
Dr Foster emphasized that lifestyle factors remain within men's control. He recommends getting six to seven hours of unbroken sleep per night, reducing stress (nine in 10 Brits have experienced high stress in the last year, per Mental Health UK), and exercising at least three to four times per week. 'The evidence is that it doesn't matter what type of exercise it is, as long as it is intense enough to get your heart rate going or get your muscles aching,' he explained. A healthy diet is also key, though only 32.5% of adults aged 16 and over consume five or more portions of fruit and vegetables daily. Maintaining a healthy weight is paramount.
If lifestyle changes don't help, Dr Foster urges men to get their testosterone levels checked. 'This is because all the lifestyle changes in the world will not undo a medically caused testosterone deficiency,' he said. 'If you have true testosterone deficiency, then the only way to treat that is with male hormone replacement, TRT.' He is seeing increasing use of TRT and advises men over 30 to get tested.
