Life-Extension Guru Bryan Johnson Says He Has Way More Microplastics in His Semen Than His Blood

Bryan Johnson seems to have never heard the phrase “too much information.” The anti-aging tech guru, who is currently engaged in a grand effort to turn himself back into a (physical) teenager, has documented his bizarre journey with a stark candor that is at once deeply cringe-inducing and somehow also sorta amazing. In the past, Johnson has shared quite startling facts about himself, revealing that—in his effort to turn back biological time—he has sometimes resorted to electro-shocking his own penis (this was supposed to produce better erections) and once accepted blood transfusions from his own teenage son.

This week, Johnson shared yet another personal insight that nobody asked for: His jizz has substantially more microplastics in it than his blood does. On X on Tuesday, Johnson posted: “I have microplastics in my ejaculate. 2x the concentration than my blood. + 167 microplastic particles in 1 ml of ejaculate + 70 microplastic particles in 1 ml of blood Ejaculate levels are 238% higher than blood. This was in Nov 2024.” He added: “Compared to my blood, my ejaculate has 239% the amount of microplastics.”

Wow, thanks dude! Very interesting stuff. Pardon me while I go wash out my ears.

Johnson is always running a battery of tests on himself, as he seeks to study the activities and practices that might crack the code of eternal youth. In that sense, Johnson has put himself up as a guinea pig in the pursuit of more optimized health regimens, which is admirable, I guess, if not a little bit insane. Johnson shared some of the insights, “Since this test in Nov 2024, I’ve dramatically reduced microplastics in my blood,” Johnson also shared on X. “By 93%. I’m going to retest ejaculate soon to see if the reduction has happened there too.”

Admittedly, Johnson is referencing a serious issue here, which is that our modern world is so plush with plastic that it’s toxically leaking into our bloodstreams (and, apparently, our jizz). In his tweets, Johnson cited a meta-analysis study published in 2024 that discussed 39 different papers on “male reproductive toxicity of microplastics (MPs) and nanoplastics (NPs).” The study found that increased levels of microplastics in males led to reduced testosterone, testicular inflammation, and “impaired spermatogenesis at tissue/organ levels.” The study concluded that, ultimately, “decreased sperm quality or quantity was noted and [had been] proved by meta-analysis.”

The glut of microplastics in our bodies is something that the scientific community has increasingly sought to warn the public about, though regulatory and political solutions remain frustratingly out of reach. With Robert F. Kennedy Jr. running the federal health bureaucracy, I wouldn’t expect an incoming top-down solution anytime soon.