Do thermal water sprays really work?

First Posted on February 3, 2021 in:insights & debunkssensitive skinshop like a pro

Do thermal water sprays really work? Does spritzing that magical hot spring water provide any proven skin benefits? Should I go with Avene or La Roche Posay thermal water? These are just a few of the questions we have gotten about thermal water based skin mists. We’ll admit, before our friends asked about decoding thermal waters, it wasn’t a topic we really thought much about. Some of the concepts and outrageous claims that came with them felt like it had BS all over it. We even ran a quick insta-poll and many of you agreed as more than 75% of you also thought that there are no proven benefits. So imagine our surprise when we went down the rabbit hole and discovered enough content that doesn’t even fit neatly into a simple Insta post…

The Data

    Thermal water of different sources have different compositions. There are a long list of skin benefit claims made around thermal water, but the unifying theme is its soothing, anti-inflammatory properties. In fact, many of the studies around thermal water were on its therapeutic benefits for patients suffering from chronic inflammatory conditions such as eczema, psoriasis, and atopic dermatitis. Here’s a quick highlight and source of some of the papers we have found.

  • An animal study on Comano thermal water that compared petrolatum wound dressing vs thermal water wound dressing on skin healing in rabbits. Study was very small, and it’s on bunnies, but did show anti-inflammation benefits.
  • An Avene study on how their thermal water decreases inflammation in patients with atopic dermatitis. It’s mostly in French, so this is just a note, we had no real takeaways here.
  • Detailed La Roche Posay thermal water overview from in vitro evidence to some clinical studies. Includes a n=92, clinical on patients with psoriasis, which combines drinking a liter of thermal water a day with a high-pressure shower for 3 weeks. Interestingly enough, it was found that the men in the clinical trial had a statistically significant improvement after treatment, but not women.
  • A Portuguese study with 22 patients with psoriasis, eczema, and atopic dermatitis that tested a cream with Monfortinho spring water versus a cream with regular lab-grade purified water.  The study showed that the thermal water performed similarly, maybe sliiighhtly better than lab water at decreasing itchiness with no statistical significance.
  • Another Portuguese study on São Pedro do Sul thermal water improving TEWL on irritated skin on just 17 people.
  • An overview article that covers various clinicals done on this subject for the uber curious.

    There’s actually a few more studies that were done but that we didn’t include on the list. Of all the thermal waters out there, unsurprisingly, Avene and La Roche Posay both have performed many tests validating their thermal water. So what does this mean? That thermal waters are worthy skin saviors after all?

Chemists’ Recommendations

Not quite… many of the studies outside of La Roche Posay and Avene are very very small with unrealistic test conditions. And if you look closer at La Roche Posay and Avene studies, many of the benefits are done at their therapy centers that use treatment methods that are a LOT more intensive than just misting a few times a day (um… let’s be real, you’re not drinking a liter of thermal water a day). So here are some of our recommendations if you would like to give thermal water mists a try.

  • For those with eczema, psoriasis, or atopic dermatitis, at most, these waters could potentially mitigate symptoms. Definitely go with an Avene or LRP since they’ve actually attempted to test these for compromised skin types. However, this absolutely does not replace any derm recommended/prescribed treatments. 
  • In fact, if you like thermal waters, just go with an Avene or LRP. Thermal water profiles vary from location to location. Just like peptide sourcing, testing is important here to indicate if there’s any skin benefit.
  • If you’re using it as a refresher on airplanes, dry offices, do follow up with a moisturizer. Mists will not help seal in the moisture especially if you have dry skin. Check out our moisturizer article for more!
So our one liner takeaway to wrap this rabbit hole up: we were pleasantly surprised that it isn’t nothing, however, in typical skin mist form, it probably wouldn’t be the missing miracle piece in your life either.


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