Bryan Johnson: Is Sauna Worth the Hype?

There's evidence that sauna is a potential detox and longevity intervention with benefits to heart, metabolism, brain health, and skin. We’re going to put it to the test.

Here’s what you need to know…

POSTED: 6/18/25

0/ Baseline: toxin levels showed one high exposure and six moderate exposures. Approximately one month prior to starting the sauna regimen, urine tests indicated one high exposure (levels exceeding the 95th percentile), and six moderate exposures ( levels between the 75th and 95th percentiles).Post-sauna: high exposures completely eliminated, only one medium exposure remained, and three previous moderate exposures became undetectable.

POSTED: 5/14/25

Interesting effects from 7 days of sauna (200°F for 20 min). It's early and I'll get more data in the coming weeks so we'll see.

Central systolic blood pressure 103→97 mmHg:

My heart, brain and all major organs are experiencing 5.83% less pressure than a week ago. I started in the lower normal range, now it is even lower in the lowest 2.5-5% for 20-year olds. 

Central pulse pressure 28→22 mmHg:

21.43% more flexible aorta and less load on my heart. 

Augmentation pressure 2→1 mmHg, and augmentation index 8→6 % 

Both indicating further decrease in my arterial stiffness and increase in aortic compliance.

Subendocardial variability ratio SEVR 220-212%

Small downwards shift of 3%, while still in mid normal range reflecting normal heart oxygenation. 

How sauna helps achieve these results?

Heat-induced vasodilation and lower sympathetic activity at rest due to repeated heat exposure.

Arterial structure remodeling and increased aortic elasticity.

Confounders to rule out

Change could be due to a small reduction in plasma volume due to repeated heat exposure, will rule out by testing my urine for hydration markers and keeping them stable.

Change can also be within the normal levels of variance for this measurement, this can be ruled out with repeated measurements showing the same trend as I continue my sauna protocol.

These improvements are in line with the strong clinical evidence supporting the cardiovascular protective effects of sauna.

POSTED: 5/14/25

My body sweats 18 oz during a 20 min sauna at 200 °F, with a sodium concentration of 25-39 mg/oz.

A single sauna session flushes 450–700 mg of sodium out of my body. ~30-50% of ideal daily intake.

I measured this because I got intense muscle cramps during sleep after starting sauna and needed to figure out the electrolyte balancing.

These results now inform my sodium sweat profile (everyone is different) and needed fluid intake before and after.

My protocol is to consume 20 oz before and 20 oz after each sauna session, each with 350 mg of sodium, 80 mg of potassium and 24 mg of magnesium. This is a Blueprint concoction that we've sourced and tested ourselves.

I used the Gatorade Sweat Patch for measurement.

POSTED: 5/7/25

0/ How it works

Heat exposure in a sauna puts your body under mild stress, triggering natural repair processes that improve overall health. Finnish dry saunas specifically use controlled heat to stimulate these beneficial responses, including: Repairing and maintaining proteins (heat shock proteins)
+ Improving blood flow and relaxing blood vessels
+ Boosting antioxidant activity
+ Optimizing metabolism
+ Enhancing fitness
+ Reducing inflammation
+ Strengthening immunity
+ Recycling and repairing cells (autophagy)

All these processes combine to give whole-body health benefits.

1/ It protects your heart

Regular sauna use (4–7 times a week, sessions lasting at least 19 minutes) can significantly improve heart health and lower blood pressure. Research shows the more often you sauna, the greater your protection from heart disease:

Heart disease risk:
2–3 times/week → 23% lower risk
4–7 times/week → 48% lower risk

High blood pressure risk (in healthy men aged 42–60):
2–3 times/week → 17% lower risk
4–7 times/week → 47% lower risk

In patients with existing heart failure, using a sauna 5 times a week for 3 weeks improved heart function by nearly 7%, lowered stress hormones by 25%, and reduced heart failure markers by over 20%. Longer and more frequent sauna sessions offer the strongest protection.

2/ It can improve mental health

Regular sauna use can lower your risk of dementia and boost your overall mental health.

+ Better sleep: Over 80% reported improved sleep quality.
+ Reduced pain: 33% experienced less muscle pain.
+ Happier mood: Regular sauna users (1–4 times/week) report feeling happier and less  stressed.
+ Lowers dementia risk: lowers by 21% (2–3 times/week) and 48% (4–7 times/week)
+ Lowers psychotic disorder risk: 4–7 times/week → 77% lower risk

3/ Reduces inflammation

Regular sauna use reduces inflammation and can ease autoimmune conditions. Studies in healthy middle-aged men show frequent sauna use lowers systemic inflammation significantly:

2–3 sessions/week: 17% lower inflammation
4–7 sessions/week: 31.5% lower inflammation

These anti-inflammatory benefits grow stronger with increased sauna frequency and are sustained over the long term. Sauna use notably reduces markers like hsCRP, fibrinogen, and white blood cell count, all linked to chronic inflammation.

As a result, regular sauna sessions improve quality of life and ease symptoms in chronic inflammatory and autoimmune diseases, such as rheumatoid arthritis.

4/ It can improve your metabolism

Sauna can improve your body composition, metabolism, and fitness levels.

It has shown:
+ Significant decrease in bad cholesterol (total cholesterol and LDL)
+ Transient significant decrease in blood fat (triglycerides)
+ Small increases in good cholesterol (HDL)

These benefits were seen in young men completing 10 sauna sessions (3 x 15 minutes, 2 min cool-downs in between).

In a low powered study (small sample size with additional limitations), research also showed a 1.07% increase in muscle mass & 7.7% increase in bone mineral density. This is based upon 12 days of high-temperature (100°C) long sauna sessions (5 x 10 min each) across 4 weeks.

6/ What about longevity?

Regular sauna use is linked to a longer lifespan. Multiple studies show that frequent, long-term sauna sessions significantly lower your risk of dying from all causes. Regular sauna use (3–7 times/week) specifically reduces the increased mortality risk from chronic inflammation (high CRP).

All-cause mortality risk (sessions >19 min):
2–3 times/week → 24% lower
4–7 times/week → 40% lower

Effect of session length:
11–19 mins → 9% lower
Over 19 mins → 17% lower

Additionally, long-term sauna use dramatically lowers the risk of dying from heart disease in men and women (average age 63, followed for 15 years):
2–3 times/week → 29% lower
4–7 times/week → 70% lower

7/ My protocol

My sauna protocol:
+ Type: Dry sauna (@thecoldplunge)
+ Temperature: 200 °F (93° C)
+ Frequency: daily, 7 days a week
+ Duration: 20-minute sessions
+ Protection: Ice pack applied to the groin area to safeguard testicular and sperm health.
+ Rehydration: 36 oz mineral-supplemented water to replenish minerals (via Blueprint electrolytes ETA this summer)

8/ How I will measure effect

Potential Benefits
+ Enhanced cellular repair mechanisms, focusing on protein and cellular maintenance and repair.
+ Increased metabolic efficiency.
+ Improved physical fitness and exercise endurance.
+ Better cardiovascular health.
+ Enhanced neurological function.
+ Possible positive changes in the gut microbiome.

Measurements
+ Heart Rate Variability (HRV)
+ Resting Heart Rate (RHR)
+ Blood Pressure (BP)
+ VO2max, grip strength, and muscle oxygenation (MOXY)
+ Bone Mineral Density (BMD)
+ Muscle Mass
+ Visceral and liver fat
+ Endothelial function markers (ADMA/SDMA, NO, and F2-Isoproteins)
+ Inflammation markers (CRP, IL-6, IL-10, TNF-a, and MMP-9)
+ Neurological markers P-tau 217 and S-100B

Bonus
+ Salt content in sweat to track my need for mineral fortification for dehydration

9/ Tips for you

+ Aim for 3–5 sauna sessions per week, lasting about 15–20 minutes each, at 175–194°F (80–90°C)
+ After workouts is ideal, as sauna use boosts muscle recovery. Always hydrate thoroughly afterward
+ Be cautious above 194°F (90°C). Cover your head with a damp cloth, breathing through it to protect your airways
+ Never use a sauna when dehydrated, and drink plenty of water afterwards to rehydrate
+ Use minerals+water to dehydrate in case you are a salty sweater (can be measured)

Skip sauna sessions if you:
+ Have serious heart issues or uncontrolled blood pressure
+ Are pregnant (consult your doctor)
+ Have an infection, fever, or feel unwell
+ Have a history of seizures
+ Struggle with respiratory conditions (asthma, COPD)
+ Have irritated or inflamed skin
+ Recently consumed alcohol or recreational drugs
+ Are taking medications such as beta-blockers, stimulants, anticholinergics, or diuretics