You've developed 'new sensitive skin' — except you haven't
Sound familiar? Products your skin has tolerated for years suddenly sting or cause redness. You develop a reaction to a fragrance that never bothered you. Your skin feels unpredictably reactive and you've started doing an elimination diet but for your skincare shelf.
Here's what's likely actually happening: your skin's microbiome has been disrupted by hormonal changes. And the solution isn't to strip back everything — it's to rebalance what's there.
What is the skin microbiome?
Your skin is home to billions of microorganisms — bacteria, fungi, and viruses — that form a complex ecosystem on your skin's surface. When this ecosystem is balanced, these microorganisms actively protect you: they crowd out harmful bacteria, maintain skin pH, support barrier function, and regulate immune responses.
When the microbiome is disrupted — through illness, stress, antibiotic use, or hormonal shifts — the skin loses this protection. The result is increased sensitivity, reactivity, dehydration, and a tendency towards inflammation.
Here's where oestrogen comes in
Oestrogen directly regulates your skin's microbiome. Research shows that oestrogen supports the diversity and abundance of beneficial bacterial strains — particularly lactobacillus species — that keep the skin's pH slightly acidic (which is where you want it for healthy barrier function). When oestrogen declines, this microbial balance shifts. The diversity of good bacteria decreases. Skin pH can rise, making the barrier less effective. And the skin's immune response becomes more easily triggered.
This is why the reactivity often feels 'sudden' — it's not about individual product ingredients, it's about a fundamental shift in how your skin's ecosystem is functioning.
What prebiotics actually do
Prebiotics are not probiotics — an important distinction. Probiotics introduce live microorganisms. Prebiotics are nutrients that feed the beneficial bacteria already present on your skin, helping them repopulate and restore balance. Applied topically, they help shift the microbiome back towards the balanced state it had when oestrogen was doing its job.
When the microbiome is functioning well again, something quite lovely happens: the skin calms down. Products stop stinging. Redness reduces. The barrier functions better. It's not magic — it's just biology working properly again.
The prebiotic serum approach
Our Microbiome Reset Serum was formulated around Lactobacillus Ferment Lysate — a prebiotic that feeds the beneficial bacteria your skin's microbiome needs to function. Paired with Hydrolyzed Hyaluronic Acid and Sodium PCA, it also addresses the dehydration that comes alongside microbiome disruption.
It's a jelly texture (slightly unusual, very satisfying) that absorbs instantly and sits comfortably under moisturiser morning and evening. Consistency is what makes this one work — the microbiome responds to regular feeding, not occasional applications.
What else disrupts the microbiome?
A few things worth knowing: harsh cleansers strip the skin's natural bacterial population alongside the grime (another argument for oil-to-milk over foaming). Over-exfoliation does the same. Very high-pH or very low-pH products can shift the balance. The goal is a routine that cleanses effectively without destroying everything beneficial in the process.
Your skin's microbiome is remarkably resilient — it responds quickly when you give it the right support. Most people with reactive, newly-sensitive skin notice significant calming within two to four weeks of consistent prebiotic use.