2025 INGREDIENT TRENDS: ECTOIN IS THE NEW HYALURONIC ACID - What is Ectoin? What’s the difference between Ectoin and Hyaluronic Acid?
Ingredient trends in skincare are as common as New Year’s resolutions to get more exercise, get more disciplined, and get more rest. They’re often just as fleeting.
Yet, sometimes buzzy ingredients persist and even become mainstays. Niacinamide started trending as an active around 2017. Today it’s everywhere. Retinol, Vitamin C and Hyaluronic Acid all started as ingredient trends, too. And all have endured.
Until this year, each of those powerhouse ingredients has played a central role in my own daily skincare routine. But as I’ve delved into ingredient science and the intricacies of product formulation – specifically the ability (or inability!) of actives to penetrate the skin barrier – I’ve become more discerning. And that’s meant dropping Hyaluronic Acid from my repertoire. (More on why below.)
As the skincare category continues to blur the lines between beauty, wellness and science, a new generation of transformational ingredients is coming to market. Some are backed by rigorous data, others by social buzz – but all are reshaping what expectations – and results – look like in 2025 and beyond.
Key Takeaways:
Several ingredient trends have risen to the surface this year: exosomes, growth factors, Ectoin and NAD+ boosters.
Ectoin is a multi-functional active with both humectant and reparative properties.
Two excellent hydrating serums with Ectoin were introduced: Paula’s Choice 7% Ectoin Booster Serum and The INKEY List’s Ectoin Hydro-Barrier Serum.
This year, several ingredient trends have risen to the surface in the dynamic beauty marketplace: exosomes, growth factors, Ectoin and NAD+ boosters. I’ve explored the science and benefits of each in my conversations with brand founders, dermatologists and cosmetic chemists on my blog and podcast throughout the year.
I’ve been particularly intrigued by Ectoin and joked that it is the new Hyaluronic Acid. It isn’t yet, but it should be! Both actives are effective humectants that lock hydration in the skin. And each possesses benefits beyond mere hydration: HA helps to soothe irritation; Ectoin helps to repair damage.
Over the past year, two well-formulated hydrating serums with Ectoin have stood out to me: the Paula’s Choice 7% Ectoin Booster Serum and The INKEY List’s Ectoin Hydro-Barrier Serum – which I reviewed on the Skincarma Blog here.
Each of these superb serums has found a place in my skincare routines (one AM, one PM), replacing Hyaluronic Acid entirely.
1. What is ectoin?
So what exactly is Ectoin that makes it exceptional and even essential?
An extremolyte or stress-protection molecule found in microorganisms living in extreme environments;
A powerful humectant proven more effective than Hyaluronic Acid (HA);
Due to its lower molecular weight than HA, Ectoin penetrates skin more deeply;
Beneficial for barrier repair, long-term hydration and soothing sensitivity.
Hydration is key for healthy skin and humectants are an essential component in optimizing your skin’s hydration. Due to its lower molecular weight (below the “500 Dalton Rule”), Ectoin, penetrates deep into the skin to lock water in more effectively than the most common humectant, Hyaluronic Acid.
Sources: PubMed Central - In vivo assessment of Ectoin: a randomized, vehicle-controlled clinical trial; Paula’s Choice - What Does Ectoin Do for Skin?
2. What does ectoin do in skincare?
Ectoin is a multi-functional active with both humectant and reparative properties.
Shields skin cells from stress by forming a protective “hydration shell” around proteins, lipids, and cell membranes.
Reduces inflammation and irritation, leaving skin more resilient and calm.
Strengthens the skin barrier and helps normalize structure and functions under environmental stress.
Reduces trans-epidermal water loss (TEWL) and supports long-lasting hydration.
Supports recovery in sensitive, compromised, or post-procedure skin.
Penetrates easily and deeply due to its low molecular weight (~142 Da), allowing it to work beyond the skin’s surface where Hyaluronic Acid can’t reach.
Sources: Paula’s Choice - What Does Ectoin Do for Skin?; The INKEY List - What is Ectoin?
3. What’s the difference between ectoin and hyaluronic acid?
Both Ectoin and Hyaluronic Acid are naturally occurring humectants popular in skincare products for hydrating and soothing the skin. But that’s where their key similarities end.
Ectoin protects the skin barrier by forming a shield around skin cells, preventing water loss and environmental damage. Hyaluronic Acid hydrates by drawing moisture from the air into the skin and pulling water to the surface from skin’s deeper water reserves. (This is not ideal.)
Ectoin is great for more long-lasting hydration and repair while Hyaluronic Acid is best for instantly boosting hydration and plumping the skin surface.
Notably, Ectoin has a small molecular weight (~142 Da), easily passing the 500-Dalton rule which governs penetration of molecules through the skin barrier. On the other hand, the molecular weight of Hyaluronic Acid can range from <20,000 Da for low molecular weight HA to >1,000,000 Da for high molecular weight molecules.
Sources: Paula’s Choice - What Does Ectoin Do for Skin?; JOJ Dermatology & Cosmetics - Skin Penetration Ability of 12 Hyaluronic Acids with Different Molecular Weights After Topical Application
4. What are the best ectoin serums?
There are several well-formulated face serums with Ectoin that have been introduced over the past year, including excellent face serums and creams from: Allies of Skin, The INKEY List, Skinfix and Paula’s Choice. (All are 1 oz. / 30 mL)
Paula’s Choice 7% Ectoin Booster Serum | $44 – contains the highest concentration of Ectoin I’ve seen and combines Ectoin and seven distinct Hyaluronic Acid molecules.
The INKEY List Ectoin Hydro-Barrier Serum | $15 – is the most affordable Ectoin serum and combines 2% Ectoin, 2.5% multi-molecular Hyaluronic Acid and 1% ceramides.
Allies of Skin Copper Tripeptide & Ectoin Advanced Repair Serum | $199 – blends 2% Ectoin with a 5% peptide complex, including copper peptides; it’s relatively expensive.
Skinfix Exo + Ectoin Intensive Repair Baume | $69 – is dubbed a Retinol alternative for sensitive skin that combines two trending actives: Ectoin and exosomes.
5. Product Review
As with the vast majority of facial skincare products, the Paula’s Choice 7% Ectoin Booster Serum is best-in-class. A seven percent concentration of Ectoin appears to be the highest among the range of hydrating serums with Ectoin introduced this year.
That high percentage is reminiscent of the 10% concentration of Niacinamide that the brand introduced in its iconic antioxidant serum, the Paula’s Choice 10% Niacinamide Booster. It was my first experience with Niacinamide and remains my favorite skincare product 8 years after it launched.
While not as light, Paula’s milky, silky 7% Ectoin Booster Serum is just as easily layered into the serum step of your existing routine.
Beyond that elevated concentration of 7% Ectoin, it also contains a complex of seven Hyaluronic Acid molecules of varying weights for broader penetration and more dispersed hydration. But, as I said above, even the lowest molecular weight HA won’t get very deep.
So why include both Ectoin and HA? Well, the combination of the two humectants means the formula will deliver both an instant and a long-term hydrating benefit. The Hyaluronic Acid plumps the skin surface for a temporary, cushiony feel while the Ectoin delivers more sustained and substantive hydration.
The smart pairing of the two molecules makes it perhaps the best hydrating serum available today.
In fact, the brand claims that the Paula’s Choice 7% Ectoin Booster Serum is “clinically proven to soothe, help protect, restore resilience and visibly repair the barrier in 7 days – for dewier, stronger, makeup-optional skin.”
If you’re using a hydrating serum with Hyaluronic Acid, you should consider finishing it up then stepping up your game with an Ectoin serum like this one – or any of the four I’ve recommended above.
6. Pros & Cons
What I like about it: The Paula’s Choice 7% Ectoin Booster Serum is likely the best hydrating serum with Ectoin available today. With what appears to be the highest concentration of Ectoin in a single formula, its combination of both Ectoin and multi-molecular HA make it effective as an instant and long-term hydrator. I also love how easily layered it is into an existing routine.
What I don’t like about it: Though I’m not a fan of Hyaluronic Acid, this serum overcomes the ingredient’s main drawbacks, particularly the temporary plumping effect.
Who it’s for: All skin types.
SHOP THE BLOG: Want to try it for yourself? Purchase the Paula’s Choice 7% Ectoin Booster Serum for $44 here.
FIND OUT WHICH SERUM PERFORMED BETTER – AND BY HOW MUCH!
The Ingredient List of the Paula’s Choice 7% Ectoin Booster Serum:
aox|so|h, Isopentyldiol solv|h|emo, Triethylhexanoin emo|perf, Diisopropyl Adipate emo|solv 0 0, Isoamyl Laurate emo, Dicaprylyl Carbonate emo, Undecane emo, Polyglyceryl-4 Oleate emu, Squalane sii|emo 0 1, Tridecane perf, Polyglyceryl-6 Oleate emu, Polyhydroxystearic Acid emu, 1,2-Hexanediol solv, Simmondsia Chinensis (Jojoba) Seed Oil emo 0 0-2, Sodium Hyaluronate sii|h 0 0, Caprylic/Capric Triglyceride emo, Tocopherol aox 0-3 0-3, Hydroxyacetophenone aox|pres, Glycogen h, Coco-Caprylate/Caprate emo, Hydrogenated Olive Oil Unsaponifiables emo, Sodium Phytate chel, Citric Acid buff, Stearalkonium Hectorite vc, Polyglyceryl-3 Diisostearate emu 0 4, Polyglyceryl-3 Polyricinoleate emu|vc
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