Can Sauna Help With Microplastics and Chemical “Detox”?

INTRODUCTION

“Detox” is one of the most abused words in health marketing. Most of the time it means nothing more than “we’d like to sell you something.”

Bryan Johnson’s sauna experiment is different in one important way: he actually published before-and-after lab tests on specific chemicals and microplastics, and he explicitly credits high-heat sauna as a major lever. (Blueprint Bryan Johnson)

At Simply Sauna — a mobile wood-fired barrel sauna rental based in Bedminster, New Jersey — we’re interested in what’s real here: what he measured, what changed, what research actually says about sauna, sweat, and toxins, and what a normal person should take away from “sauna detox” claims.

This article walks through:

• what he measured

• what changed

• what existing research says about sauna, sweat, and toxin elimination

• and how a reasonable person should interpret “sauna detox” claims

WHY SAUNA “DETOX” CLAIMS ARE SO POPULAR

The story is intuitive:

• You sit in a hot box.

• You sweat a ton.

• Sweat feels like you’re “pushing stuff out.”

On top of that, we live in a world where:

• microplastics have been found in blood, semen, placenta, and other tissues (ACS)

• pesticides, flame retardants, heavy metals, and phthalates show up in most people tested in biomonitoring surveys

So the desire for some kind of “clean out the junk” protocol is understandable. The question is not “does this feel good?” but “what’s actually happening?”

WHAT BRYAN JOHNSON ACTUALLY MEASURED

Environmental chemicals

In his sauna write-ups and related content, Bryan has shared lab results for specific environmental chemicals, including:

• herbicide metabolites like 2,4-Dichlorophenoxyacetic acid (2,4-D)

• phthalate metabolites (MBP, MEHP, MEP, etc.)

• other non-metal toxicants measured via a urine toxicant panel (Blueprint Bryan Johnson)

He frames sauna as a key intervention and reports moving several markers from “high” to “medium” or “low” after a period of frequent, high-heat sauna sessions.

Microplastics in blood and semen

He has also talked about microplastic measurements in his own body:

• reporting an ~85% reduction in microplastics in semen (for example, from around 165 down to about 20 particles/mL over several months)

• similar large reductions in microplastics in his blood over time

He’s shared those numbers directly in posts on X and LinkedIn. (X, LinkedIn)

He attributes this mainly to:

• daily or near-daily 200°F dry sauna for about 20 minutes

• combined with a general reduction in plastic exposure (glass containers, filtered water, avoiding plastic tools, etc.)

HOW HE INTERPRETS THOSE RESULTS

Bryan’s narrative is straightforward:

• modern life loads you with microplastics and industrial chemicals

• frequent, high-heat sauna plus reduced exposure can meaningfully lower that burden

• his lab tests are a proof-of-concept that this approach can work for at least one person (Blueprint Bryan Johnson)

He’s careful to say “we’re going to put it to the test” more than “this is proven for everyone,” but the implication is clear: sauna is a central detox lever in his Blueprint.

WHAT WE KNOW ABOUT SAUNA, SWEAT, AND TOXINS

There actually is some research here, separate from Bryan’s story.

Sweat can carry certain pollutants

Several studies have shown that induced sweating (by sauna, exercise, or heat) can increase excretion of certain compounds, including:

• some phthalates (DEHP, MEHP)

• some flame retardants and PCB-type chemicals

• some heavy metals in specific contexts (PMC)

One review framed sauna as potentially useful to help eliminate selected toxicants in people with known exposures, while also highlighting how limited the data is and how carefully it should be interpreted. (PMC)

Microplastics are newer

For microplastics, the science is much younger:

• We now know microplastics show up in blood, semen, placenta, and other tissues in humans. (ACS)

• We don’t yet have large, controlled studies showing how different interventions (sauna, diet changes, filters, etc.) alter those levels over time.

So Bryan’s data is more like an early, well-documented case study than something sitting on top of a big evidence base.

The clinical impact is still unknown

Even where we can show increased excretion or lower lab values:

• It’s not always clear how much total body burden changes.

• It’s definitely not clear how much that changes future disease risk.

Having a lower urine level of a metabolite is directionally good. It’s not the same as “sauna cured my toxin problem.”

THE EVIDENCE PROBLEM: N=1 VS SMALL, IMPERFECT STUDIES

Bryan’s case: valuable but anecdotal

With his n=1 experiment:

• there’s one person

• on many simultaneous interventions

• measuring lots of variables over time

That makes his data:

• much more interesting than vague marketing

• still not a general law for all humans

We can say “this protocol coincided with big drops in certain markers for him,” not “this protocol will cause the same drops for you.”

The detox literature: real, but fragile

On the other side, the “sauna detox” literature:

• often has small sample sizes

• focuses on people with specific high exposures (e.g. workers with known PCB or solvent exposure)

• uses pre/post designs without control groups

• carries all the issues John Ioannidis flagged in “Why Most Published Research Findings Are False”: low power, bias, and flexible analysis choices (PLOS)

So you have:

• interesting n=1 data

• suggestive, small-scale studies

Both point to “sauna can help move some things out.” Neither justifies a guaranteed, quantified detox promise.

A SANE TAKEAWAY ON SAUNA AND “DETOX”

Here’s a more grounded way to think about it:

1. Reduce exposure first

• Less plastic, fewer pesticides, cleaner water, better air → less incoming load.

• This is the most reliable “detox protocol” you’ve got.

2. See sauna as a plausible supporting tool

• High-heat sauna definitely increases sweat.

• Sweat can carry some pollutants out.

• For some people with specific exposures, this may be clinically meaningful.

3. Don’t expect miracles

• You’re not power-washing your tissues with one weekend of sauna.

• Even with intense, frequent sauna like Bryan’s, it’s hard to attribute exact percentages to any single lever.

4. Treat your own use as an experiment

• If you’re concerned, you can work with a clinician to test specific toxicant panels before and after a period of consistent sauna use.

• Just recognize the limitations in the tests themselves and in the research.

WHERE A TRADITIONAL FINNISH-STYLE SAUNA FITS IN

If you want to explore this without building an entire Blueprint lab, you basically need:

• the same kind of environment

• but on human terms.

A wood-fired barrel sauna (like Simply Sauna’s units):

• recreates the dry, high-heat Finnish-style conditions that both the detox studies and Bryan’s protocol rely on (PMC)

• lets you experience deep sweating in a controllable, time-limited way

• doesn’t require tearing up your house or buying a big infrared setup

If you’re in our service area — roughly a 60-mile radius from Bedminster, New Jersey into parts of NJ, NY, and PA — you can treat a weekend rental as:

• a concentrated trial run: two or three evenings of proper sweating

• a way to see how your body responds, subjectively, to real Finnish-style heat

• a starting point, not a complete detox program

It’s a practical way to test sauna as one part of a longer-term “less junk in, more junk out” strategy.

CLOSING THOUGHTS

Sauna as “detox” is neither pure snake oil nor a magic filter.

What we can say, with a straight face, is:

• Some toxins and microplastics can be measured in human sweat and appear to decrease with certain sauna protocols.

• Bryan Johnson’s data is a vivid example of one person using daily high-heat sauna and seeing large shifts in his own markers.

• The broader science is promising but small and compromised enough that dogmatic claims are not honest.

If you like the idea of using sauna as part of a long-term strategy to reduce toxic load:

• start with exposure reduction,

• add real Finnish-style heat as a supportive tool,

• and keep your expectations curious, not magical.

And if you’re near Bedminster, NJ and want to experiment with a Bryan-style high-heat routine in a real Finnish-style environment, a mobile wood-fired barrel sauna rental from Simply Sauna lets you do that in your own driveway — no construction, no permanent commitment, just a few days of honest heat and sweat to see how you feel.