What should you drink after a sauna?
Water plus sodium. Sweat carries both out of your body, and the sports-nutrition evidence is that restoring fluid balance takes more fluid than you lost, with electrolytes, particularly sodium, replaced as well. Water alongside salty food does that. So does an electrolyte drink. Skip alcohol during sauna use: it raises the risk of low blood pressure.
Part of the Glow Protocol guide. Start here: The Glow Protocol
Five things worth knowing
- Drink more than you sweated out, not the same amount.
- Sodium is the electrolyte that matters most for getting fluid balance back.
- Arrive hydrated. A deficit you bring in only gets bigger.
- Sweating is not a detox. The kidneys and gut clear waste.
- Alcohol and saunas do not mix.
Does a sauna dehydrate you?
It can. Sweating removes water and salt, and if you do not replace them you are left with a fluid deficit. In a 2025 study, young adults using a portable infrared sauna in repeated rounds reliably lost more than 2% of their body mass. That was a deliberate dehydration protocol, not a typical relaxing session.
How much do you sweat in a sauna?
The clearest numbers in our evidence set come from that 2025 study. Fifteen healthy young adults, 11 men and 4 women, sat in a portable infrared sauna at about 66°C (151°F) for up to 20 minutes at a time, then rested for 5 minutes at room temperature, about 23°C (73°F). They repeated the rounds until they had lost a target share of body mass: 2.8% for the men and 2.4% for the women. The protocol got people past 2% in under 180 minutes, and did so consistently when repeated at least 72 hours later.
To put 2% in everyday terms: for someone who weighs 70 kg (154 lb), it is 1.4 kg (about 3 lb).
Read that study for what it is. The researchers were trying to dehydrate people, on purpose, to a set level. It shows what a sauna can do when you keep going back in. It does not tell you how much you lose in one ordinary session.
How much water should you drink after a sauna?
More than you lost. Weigh yourself before and after: researchers use that drop in body mass as their measure of fluid lost. The evidence on rehydration is that you need a volume greater than your sweat loss, with sodium, to restore fluid balance. Your normal daily fluid needs sit on top of that.
Why more than you lost? A review of fluid and electrolyte needs states it plainly: for effective restoration of fluid balance, consuming a volume of fluid in excess of the sweat loss, and replacing electrolyte losses, particularly sodium, are essential.
Your daily baseline. The National Academies set the adequate intake of total water, from drinks and food together, at 2.7 liters a day for women and 3.7 liters for men aged 19 to 30. In US survey data, drinks supplied about 2.2 liters (74 fl oz) of that for women and 3.0 liters (101 fl oz) for men. A sauna session adds to that baseline. It does not replace it.
Should you drink electrolytes before or after a sauna?
Both moments matter, for different reasons. Before, the goal is simply to start hydrated, because a fluid deficit carries forward. After is when electrolytes do their job: the evidence calls for more fluid than you sweated out, plus sodium. They matter most after long or repeated sessions, when sweat losses are larger.
Water alone, or electrolytes?
Sweat is not plain water. It contains salt, sodium chloride, which is why the rehydration evidence singles out sodium.
That does not mean every session calls for a special drink. Food contains sodium, so water with a meal is one way to cover both. An electrolyte drink is the convenient route when you are not about to eat, or when you have sweated a lot.
Two details from a major review of sweat physiology are worth knowing:
- Salt losses vary between people. People with very salty sweat, such as those with cystic fibrosis, are at higher risk of salt imbalance during long periods of heavy sweating.
- Sweat does not drain your vitamins. The review found that sweat-induced deficiencies of trace minerals and vitamins appear to be of minimal risk.
Does sweating in a sauna detox you?
No. The same review found that the role of sweating in eliminating waste products and toxicants is minor compared with the kidneys and gastrointestinal tract. Sweat glands do not adapt to excrete more. Studies that suggested otherwise may reflect problems with their methods.
This matters for what you drink. You do not need a "detox" drink after a sauna. You need fluid and sodium.
What about alcohol?
Avoid it. A medical review of sauna benefits and risks concluded that alcohol consumption during sauna bathing increases the risk of low blood pressure, irregular heart rhythm and sudden death, and should be avoided.
A simple plan: make it a Glow Protocol
- Before. Drink normally through the day so you arrive hydrated. If you want a number later, weigh yourself.
- During. Keep water within reach for longer sessions. If you feel dizzy, faint or unwell, get out and cool down. If it does not pass, get medical help.
- After. Drink more than you lost, and include sodium, through food or an electrolyte drink. Hold off on alcohol.
- Daily. Skin hydration is built every day, not only on session days. That daily layer is Step 0.
H2Glow is Step 0: the hydration layer underneath the routine. It does not make any device work better. See the full Glow Protocol.
Check with your doctor first if you have a heart or kidney condition, are pregnant, or take medication that affects fluid balance or blood pressure.
Does a sauna hydrate your skin?
Not by adding water to it. But regular sauna use and skin hydration do appear together in one study. In 41 healthy adults, regular users of a traditional Finnish sauna had higher hydration in the outer skin layer and a more stable skin barrier than non-users. A review also found that sauna bathing does not dry the skin.
More: Does infrared sauna help your skin?
What a post-sauna drink does not do
- It does not flush toxins.
- It does not need to replace vitamins. Sweat losses of those are minimal.
- It does not make the sauna work better. It replaces what the sauna took out.
- It does not undo a session that went too long. If you feel unwell, stop.
Where H2Glow fits
After a sauna you need fluid and sodium. H2Glow is mixed into water and provides 300 mg sodium, 200 mg potassium, 150 mg magnesium and 515 mg chloride, so it covers both in one glass. How much sodium you lose depends on how much you sweat, so after a long session you may need more fluid and salt than one serving supplies.
Alongside the electrolytes, H2Glow carries skin actives, including 250 mg sodium hyaluronate and 40 mg rice phytoceramides, for the skin's own water content and barrier. No study has tested H2Glow with sauna use.
Frequently asked questions
What should you drink after a sauna?
Water plus sodium. Restoring fluid balance takes more fluid than you sweated out, with electrolytes, particularly sodium, replaced too.
How much water should you drink after a sauna?
More than you lost. Weighing yourself before and after shows the loss. The evidence does not support simply matching it.
Should you drink electrolytes before or after a sauna?
After is when they matter most, because that is when you are replacing sweat losses. Before, the aim is to start hydrated.
Does a sauna dehydrate you?
It can if you do not replace what you sweat. Repeated rounds in a portable infrared sauna took young adults past 2% body-mass loss in a 2025 study.
Is water enough after a sauna?
Water replaces the fluid but not the sodium. Water with salty food, or an electrolyte drink, covers both.
Can you drink alcohol in a sauna?
No. Alcohol during sauna bathing increases the risk of low blood pressure, irregular heart rhythm and sudden death.
Is the weight you lose in a sauna fat?
No. Researchers treat body mass lost in a sauna as fluid loss. It returns when you rehydrate, which is the point of rehydrating.
Does sweating in a sauna remove toxins?
Only to a minor degree. The kidneys and gut do nearly all of that work.
Further reading
- Infrared sauna vs traditional sauna: what's actually different
- Sauna blankets: do they work, and how to use one
- Does infrared sauna help your skin?
- Contrast therapy: sauna and cold plunge
- The Glow Protocol
- Why water isn't enough
- Electrolytes for skin: do they help?
- Why is my skin so dry in winter?
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. These statements are based on clinical research on individual ingredients. Results may vary.