Last Updated on November 5, 2025 by Giorgia Guazzarotti
Is thermal water in skincare a scam or do the French know something we don’t? Like, they go gaga over this stuff. You can’t enter a pharmacy in France without bumping into shelves stocked to the brim with all kinds of fancy water. To the rest of the us, thermal water looks like plain old water in a pretty bottle (and a high price tag)… Does it really do anything for your skin? Yes. As it turns out, it IS a godsend for sensitive, irritated skin. Here’s what the science says:
What The Heck Is Thermal Water?
Thermal water is water that comes from hot springs. It’s born deep into the ground where geothermal activity (i.e. the Earth’s natural heat) keeps it warm. As the water rises to the top, it flows through soils and rocks, eroding them. It’s this erosion that fills the water with minerals, like sodium, calcium and magnesium. They go from the soil straight into the water.
That’s why no two mineral waters are alike. What minerals – and in what amounts – are in a thermal water depends on where it comes from. For example, Avene Thermal Water has 4.8 ppm sodium, 42.7 calcium and 21.2 magnesium, while La Roche Posay Thermal Water has 10ppm sodium, 140 calcium and 4.9 magnesium.
(P.S. If you’re curious about the exact composition of popular thermal waters, check out Michelle’s post at Lab Muffin).
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What Does Thermal Water Do For Skin?
First thing first: most of the studies on thermal water are done by the companies themselves. And in vitro (not real skin), too. Take them with a grain of salt. Still, the little research we have show that thermal waters have a few superpowers:
- Boost hydration: they make skin softer and suppler.
- Reduce UV damage: the minerals in them have antioxidant properties that destroy sun-induced free radicals and reduce the risk of sunburn.
- Soothe inflammation: they decrease the amount of pro-inflammatory chemicals skin cells produce, reduce the symptoms of eczema and psoriasis and even minimise irritation from tretinoin. This, in turn, also helps your skin heal faster.
How Do You Actually Use This Stuff?
So you’ve got your fancy bottle of water. Now what? Honestly, just spray it on your face whenever. But here are the times it’s especially good:
- Right after you wash your face, before putting anything else on
- Between your serum and moisturizer to help everything sink in better
- During the day when your skin feels tight or annoyed
- After being in the sun (it feels SO good)
- When you get home from the gym and your face is all red
- On airplanes because the air up there is absolute hell on your skin
- When you’re using strong actives like retinol and your face is being dramatic about it
Important: Don’t just spray it and leave it. Pat it in or spray something else on top, otherwise it’ll evaporate and actually make your skin drier. I learned this the hard way. Also, keeping it in the fridge is chef’s kiss. Cold thermal water on angry skin? Heaven.
Who Should Actually Use Thermal Waters?
Real talk: if your skin is chill and never gets irritated, you probably won’t notice much. You might like it, but it won’t change your life. But if you have:
- Sensitive skin that hates everything
- Rosacea
- Eczema or psoriasis
- Skin that freaks out when you use retinol or acids
- Skin that gets red and angry for no reason
Then yeah, get yourself a bottle. There are actual clinical studies showing it helps – like one study had people with psoriasis see a 47% improvement after 3 weeks. That’s not nothing. It’s also really good for post-procedure skin if you’ve gotten a peel or laser treatment and your face is raw.
Are There Any Side Effects?
Here’s the thing: thermal water has basically no side effects. Like, almost none. No irritation, no breakouts, nothing. The only “problems” are:
- It’s expensive
- If you let it evaporate without patting it in, it can dry your skin out
That’s it. It’s literally one of the safest things you can put on your face, which is probably why it’s so popular for sensitive skin.
What Are The Best Thermal Waters?
I wouldn’t say there is a best thermal water. It just depends on what your skin likes best. But the most popular options are:
- Avene Thermal Water ($20.00): available at Cult Beauty, Dermstore, Look Fantastic, Superdrug, and Ulta
- La Roche Posay Thermal Spring Water ($19.00): available at Boots, Dermstore, and Look Fantastic, Superdrug, and Ulta
- Vichy Mineralizing Thermal Spa Water ($11.99): available at Dermstore and Look Fantastic
FAQs
Wait, is this just expensive tap water?
No! Studies actually compared thermal water to regular tap water and found real differences in how it affects your skin’s bacteria and overall condition. According to science, “The thermal water decreased the number of certain inflammatory infectious agents and could enhance some of their positive effects, which have been proven at the molecular level.” The minerals do matter.
Can I make it at home?
Nope. You can’t just add minerals to water and get the same thing. The specific combination and concentration matters, and that only happens naturally underground.
Which brand should I get?
La Roche-Posay and Avène have the most actual scientific studies backing them up. Other brands might be great too, but there’s less research proving it. Different thermal waters have different minerals – some have more selenium, others more silica or calcium – so they each do slightly different things.
Can I use it with my other products?
Yes! It plays nice with everything. Actually, studies found it helps reduce the irritation from tretinoin, so it’s good to pair with strong actives.
Is it worth the money?
Depends on your skin. If you have reactive, sensitive, or inflamed skin, probably yes. If your skin is tough and unbothered, maybe skip it. You’re not missing out on miracles, but it genuinely helps when your skin is being a drama queen.
How long does a bottle last?
If you’re spraying it twice a day every day, maybe 1-2 months. If you only use it when your skin acts up, way longer.
Can I just use this instead of moisturizer?
God no. Thermal water adds moisture but doesn’t lock it in. You still need a moisturizer on top or everything just evaporates.
The Verdict: Should You Buy Thermal Water?
Look, I’m not gonna lie – it feels ridiculous to pay $15-20 for water in a spray bottle. I get it. But here’s the deal: if you have sensitive or reactive skin, this stuff is actually legit. The research shows it’s anti-inflammatory, helps your skin’s immune response, and has antioxidant properties. It’s not magic, but it’s not bullshit either.
The French aren’t crazy (well, not about this anyway). They’re just really into taking care of sensitive skin, and thermal water is genuinely one of the best things for it. Is it essential? No. Will it change your life? Probably not. But will it calm down your angry skin faster than almost anything else? Yeah, actually.
So if your skin is constantly pissed off at the world, maybe give it a shot. If your skin is fine, save your money for something more exciting. f you’re curious to see what they can do for you or need a little extra hydration, they may be worth a try. But they’re by no means a must have for everyone. I use one just on hot summer days. I like to keep my skincare routine as short as possible. 😉 Either way, at least now you know what all those French pharmacy shelves are about.
is the nitrogen used as a propellant bad for skin?
JR, no it’s not. Nitrogen gas is very unreactive and won’t cause problems for your skin.
I have a question – When do you use it? I mean, do you use it on top of makeup, after washing your face in the morning but before using skincare products, after skincare products but before sunblock, or after sunblock but before makeup? Or is that supposed to replace water when you wash your face? I’m sorry to ask what seems like a silly question but I never really understood how this product is supposed to be used.
JD, you can spray it on straight after cleansing or just use it throughout the day on top of makeup if you need a little refresh.
Thermal water completely changed my dry, sensitive skin. It’s the real deal! I use it after cleansing and to refresh my face on hot summer days. It’s also great for long flights. Spray a little on your face before you land and it’s a great way to feel more refreshed.
Emily, thanks for sharing your experience. So glad it’s working so well for you!