Prebiotics. Probiotics. Postbiotics. Most of us have heard at least one of these words on a skincare label by now. But what's actually the difference, and which ones are worth paying for?
Here's the short answer: each works differently in a formula, and understanding how changes what you should look for.
Why your skin's microbiome matters
Healthy, radiant skin relies on two fundamentals. One is a strong skin barrier. The other is a diverse, balanced microbiome, the trillions of bacteria, yeasts and other microorganisms living on your skin right now.
Unlike your gut, which offers a fairly stable environment, your skin is exposed and vulnerable. Sunlight, preservative-rich skincare, temperature changes, sweat and stress all chip away at that balance daily. When the less helpful microbes get the upper hand, that's when sensitivity, breakouts and dryness tend to follow. When the microbiome is supported, skin becomes calmer, more resilient and better at holding onto hydration.
What are prebiotics?
Prebiotics are plant fibres that feed the beneficial bacteria already living on your skin. Found in ingredients like oats, mushrooms, rice and seaweed, they help good bacteria thrive while crowding out the bacteria that cause problems.
Crucially, prebiotics are stable in a formula. They don't break down when mixed with other ingredients, so what's on the label is what reaches your skin. This is why we build our Cleanser and Serum around them, they're the most reliable way to support the microbiome every day.
What are probiotics?
Probiotics are the live, beneficial bacteria themselves. In theory, they work by keeping harmful bacteria from breaching the skin barrier.
In practice, live bacteria are unstable once formulated. Preservatives, temperature changes and pH shifts can kill them off before the product ever reaches your face, which means many probiotic skincare products may offer little real benefit despite the promise on the label.
What are postbiotics?
Postbiotics are the byproducts that healthy bacteria produce naturally, things like antioxidant and anti-inflammatory compounds. Unlike probiotics, they don't need to survive as living organisms to work, which makes them far more stable in a formula.
A well-supported microbiome produces these for you over time. But stabilised postbiotic ferments, as an ingredient, can also deliver those same benefits directly and immediately, which makes them useful when skin needs concentrated barrier support.
The Darl' approach
We formulate around prebiotics first, because a healthy, supported microbiome produces its own postbiotic benefits over time. That's why you'll find prebiotic ingredients like Glucomannan, Beta Glucan and Seaweed Extract throughout the range, in the Darl' Cleanser and Darl' Serum.
But there's a place for postbiotics too. When the barrier needs concentrated, immediate support, stabilised postbiotic ferments can deliver those same calming, barrier-strengthening benefits directly - without waiting for the microbiome to catch up. That's the thinking behind our upcoming moisturiser, which pairs postbiotic ferments with our ceramide complex for targeted barrier repair.
Feed the microbiome daily. Support it directly when it needs backup.