Biohacker Bryan Johnson claims he 'eliminated' most of the toxic microplastics from his body in less than a year.
The 48-year-old, who claims to be more than a decade younger biologically, wrote on X this week that from November 2024 to July 2025, he lowered the amount of microplastics in his semen from 165 particles per milliliter (particles/mL) to 20, an 88 percent decline.
And the microplastics in his blood allegedly diminished 85 percent between October 2024 and May 2025, from 70 particles/mL to 10 particles/mL.
Microplastics are tiny particles smaller than a grain of sand that seep from food containers, water, baby toys and even face masks popularized by the Covid pandemic, into the blood. From there, they accumulate in the brain, heart and other vital organs and lead to widespread inflammation, infertility and potentially some forms of cancer.
Virtually all humans have microplastics circulating in their body, and studies estimate the average person ingests 50,000 of these particles every year.
While research into where exactly microplastics are coming from is still ongoing, experts have suggested avoiding plastic food containers, swapping out non-stick cookware and ditching toilet paper for a bidet could gradually slow exposure.
Johnson claims using a sauna every day for 20 minutes helped him sweat microplastics out of his body, as well as cutting out plastic microwavable containers and plastic cutting boards.
He also touted a reverse osmosis water system, a device that uses a high-pressure pump to force water through a barrier with extremely small pores that allows water to pass through but traps harmful contaminants.

However, the evidence surrounding the devices, which cost upwards of $600, is limited.
Johnson wrote on X: 'To our knowledge, this is the first report of any correlation (esp in the same person over two timepoints) between blood and semen microplastic levels, demonstrating successful microplastic detoxification in the semen following that in the blood.
'My results offer a new sense of hope for the detoxification of microplastics from the testis and semen, especially after the concerns raised by a study last year.'
The study in question, published last May in the journal Toxicological Sciences, looked at microplastic levels in 23 testes from deceased men, as well as testicular tissue from deceased dogs.
All of those tested showed detectable levels of 12 types of microplastics, which the researchers warned could lead to low sperm count and infertility.
A recent meta-analysis of 36 studies, for example, found that microplastics induce oxidative stress in the male reproductive organs, leading to testicular inflammation, cell death, and reduced testosterone levels, sperm production and motility, which is how well sperm moves to fertilize an egg.
Johnson said: 'Microplastics in the testis and semen can disrupt sperm motility, hormones and fertility markers. The good news [is] this seems all reversible based on my results.'
Johnson claimed he uses a sauna set at 200 degrees Fahrenheit (93 degrees Celsius) for 20 minutes each day and then he puts ice on his testicles.


'The therapy we think most responsible for this reduction is sauna as it also eliminated most environmental toxins in my body, including those linked to various plastics,' he said.
Saunas induce intense sweating, a process that may help filter chemicals found in microplastics, such as BPA and phthalates, out of the body. However, the relationship between saunas specifically and microplastics has not been studied.
Icing the testicles after is thought to help protect against sperm damage caused by the intense heat.
As for plastic kitchen tools, a study published in February found eating out of plastic containers regularly led to a 13 percent increased risk of developing heart failure due to microplastics damaging heart tissues.
It's unclear how exactly Johnson tested his microplastic blood and semen levels and if he has sustained that progress.