Bryan Johnson’s latest biohack is nuts.

Over the years, the tech mogul has turned his quest for eternal life into a public spectacle, subjecting himself to extreme anti-aging experiments and sharing how they affect even the most intimate parts of his body in startling detail .

This week, the 48-year-old raised eyebrows by boasting about a new feat involving his testicles, which he said “may be a world-first breakthrough in fertility research.”

“This should not be possible,” Johnson wrote in a May 7 post on X .

Biohacker Bryan Johnson, 48, claims to have pulled off a first-of-its-kind achievement with his testicles. Bloomberg via Getty Images

The breakthrough?…