How To Formulate Modern Serums: What Actually Matters Now

Skin hasn’t become more complex - but our understanding of it has. 

We know how it hydrates, repairs, protects, and responds. We even know that your skin hosts an entire world of... not bugs – but it certainly looks like bugs under a microscope. 

And with that, the way we care for our skin has evolved too. 

One of the simplest ways we’ve done that is through serums. 

They’ve always been a favourite; easy to formulate, easy to use, and a great way to deliver specific ingredients to the skin. 

But as our understanding of skin has grown, serums have started to change with it. 

Why Choose Serums? 

Serums are one of the most versatile and effective products you can formulate. 

Not just because they’re simple to make – but because they sit in a unique space: 

Less complex than an emulsion, but still capable of delivering meaningful results. 

Their lightweight nature means they absorb quickly (making them suitable for most skin types), but more importantly, they layer easily. 

A serum doesn’t need to do everything on its own. It can: 

• deliver hydration  
• support the skin barrier  
• introduce targeted actives  
• and still leave room for oils, creams, or balms to follow  

This makes serums incredibly flexible – both in formulation and in use. 

They also offer a few practical advantages: 

• Simpler formulation – you’re less likely to combine ingredients that don’t want to work together (literally oil and water), which means fewer stability challenges  
• Targeted support – easy to design around a specific function or need  
• Customisable – can be adjusted or layered depending on the skin  
• Lightweight feel – ideal for daily use, even on sensitive or reactive skin  

In many ways, a well-made serum becomes the core of a routine – the step where most of the functional work happens. 

What Makes a Modern Serum Effective?

Serums Focus on Long-Term Skin Health

The conversation around self-care, from physical health to mental fortitude to skincare, has been notably shifting. 

We’ve become too wise for quick fixes or easy, unsustainable boosts. 

It’s becoming more about how we support the body long-term. How do we keep it functioning well, balanced, and resilient over time? 

And the nice thing is… in skincare this doesn’t require complicated or inaccessible ingredients. 

In natural formulation, this already looks like: 

• supporting the barrier with the nourishing oils and fats 
• keeping hydration levels up with humectants like glycerine and aloe vera 
• calming things down with soothing botanicals  
• adding in antioxidants to help the skin deal with daily stress  
• and avoiding ingredients that do harm to the skin, even though the immediate benefits might seem enticing  

Instead of pushing the skin to change quickly, we’re supporting it better with ingredients that support greater care over time. 

Modern Serums Use Ingredient Synergy (Not Just One Hero Ingredient) 

The industry standard for serums used to be: Powerful product built around one powerful ingredient. 

Think of classics like Hyaluronic acid, Vitamin C or everybody's favourite - Niacinamide. 

Clear mechanisms. Easy to understand and brand. Easy to sell. 

And hey, those are all great. But many people now understand that skin concerns are rarely just down to one problem. Dull skin isn’t only about needing vitamin C- it might also be dehydration, or a compromised barrier. 

Focusing on a single “hero” ingredient can miss the bigger picture - like putting a plaster on a crack in a wall. 

What’s starting to shift now is a more holistic approach. 

Instead of asking “what’s the hero?”, it becomes:  

What is this formula actually doing for the skin overall? 

So even a simple serum might: 

• hydrate  
• support the barrier  
• calm irritation  
• and offer some protection  

It’s not necessarily about overloading your serum with every ingredient. 

It’s about choosing ingredients that make sense together. 

Multi-Layered Hydration Matters in Serums

Hydration is also becoming more nuanced. 

Because even though most hydration happens in the outer layer of the skin, how that hydration behaves can be very different. 

And that’s why two hydrating serums can feel completely different - even if they’re both “hydrating”. 

In DIY terms, this can be simple: 

• Glycerine - pulls water into the skin strongly and holds onto it, gives a full, hydrated feel 
• Sodium lactate - binds water more dynamically and integrates into the skin’s natural moisturising system, feels lighter 
• Aloe - doesn’t pull in as much water, but gently hydrates and calms the skin 
• Film-formers (like proteins or gums) - sit on the surface and slow down water loss, making hydration last longer and often helps with that glass skin look 
• Hyaluronic acid - mostly sits on the surface, providing instant plumpness, but can feel tight if used alone 
• Lactic acid - hydrates and exfoliates, improving smoothness and brightness, not just hydration 

Using just one humectant can still leave you with a tightness, or hydration that quickly fades – this is why combining them works better than relying on just one. 

Prioritising The Barrier In Serum Formulation

Instead of constantly trying to “treat” the skin – like throwing a high dose of actives at one concern and hoping it fixes everything - the focus is moving toward protecting and maintaining the barrier. 

Because the barrier is the foundation of everything.  

When it’s compromised, everything else tends to follow: 

• sensitivity  
• dryness  
• breakouts  
• general imbalance  

So modern serums are starting to meet this need. 

In natural formulation, that can look like: 

• oils rich in essential fatty acids (like grapeseed)  
• more nourishing oils (like avocado or moringa)  
• calming extracts (like glycerites, calendula or chamomile)  

Less extremes. More consistency. 

Making Serums Microbiome-Friendly

I’m sure you’ve seen more talk about the skin microbiome in the past few years – even from us. 

While it sounds very complicated, in practice, it’s quite simple. 

It’s not about adding bacteria to your products (so please... put the strawberry yoghurt down, Rachel). 

It’s about creating an environment where the skin can stay balanced. 

So that means: 

• not overdoing harsh ingredients  
• keeping your skin hydrated  
• supporting the barrier  
• and maybe including gentle prebiotic ingredients like inulin, oats, or honey to nourish your dermal microbiome 

To be fair to our beautiful and lovely Rachel, Greek Yoghurt can be lovely on the skin as a simple mask – you can even add a pinch of turmeric or a calming extract like gotu kola to elevate it. 

Just keep it as a fresh, rinse-off treatment - not something to build into your serum. 

Fermented ingredients can be really interesting here too. 

They essentially provide some of the compounds a healthy microbiome would produce – helping to  soothe skin , support the skin barrier , and give some of those benefits more directly. 

But even without fermented ingredients, a well-balanced serum can do much of the work. 

Texture Matters More In Modern Serums

Serums are also changing in how they feel. 

They’re not all just thin, watery liquids anymore. 

There’s more focus now on texture – how the product sits on the skin, how it absorbs, how it feels during and after application. 

Because skincare isn’t just physical anymore – it’s also sensorial. 

How something feels, smells, and applies really does matter. 

We’re starting to understand that skin, the gut, and stress are connected. 

Products that feel calming, soft, comforting – even just easy to use – play a role beyond just the ingredients themselves. 

So you’ll start to see: 

• slightly thicker, more cushioned water serums  
• lightweight and targeted oil serums  
• lighter, almost milky textured serums 

And even subtle things like: 

• a softer scent profile (from hydrosols or very gentle essential oils)  
• a smoother glide  
• a less tacky finish  

All contribute to the overall experience. 

And in DIY, this is something you can play with quite easily: 

• adjusting your humectant levels  
• adding a bit of thickener  
• or just being more intentional about how your phases come together  

Because experience is the line between a product you like and a product you’ll love and use again. 

And that’s where the real results come from. 

The Serum Shift Isn’t Limited To Facial Skin 

What’s interesting is that this way of thinking - supporting, layering, and working with the skin - isn’t staying in facial skincare. 

It’s starting to show up across the board. 

Hair care. Scalp care. Even body care. 

Once you understand the principle, you start to see it everywhere. 

How to Use Serums in Hair and Scalp Care 

While serums are a skincare staple, we’re starting to see the same thinking move into hair and scalp care. 

And it makes sense. 

Healthy hair starts at the scalp. 

So many of the same ideas apply: 

• supporting the barrier 
• maintaining hydration 
• working with (not against) the microbiome 

But hair serums do behave a little differently. 

You can generally go heavier, depending on your hair type, and the focus shifts slightly from just skin support to also: 

• smoothing 
• conditioning 
• protecting the hair fibre 
• nourishing while avoiding that sticky feeling that can be incredibly frustrating in hair 

This is where ingredients like: 

• guar hydroxypropyltrimonium chloride (conditioning, slip) 
• argan oil (shine, nourishment) 
• broccoli seed oil (natural silicone-like feel) 
• batana oil (deep repair and richness) 

Really start to shine. Even botanical extracts and panthenol make for great additions here! 

So while the philosophy stays the same - support, don’t overwhelm - the execution shifts depending on whether you’re formulating for skin, scalp, or hair. 

How to Use Serums in Body Care

Serums aren’t just for above the neck. Body care is quietly moving in the same direction. 

Instead of heavy creams alone, there’s space for lighter, more functional products that support the skin without overwhelming it. 

A body serum is simply a more lightweight way to deliver: 

• hydration 
• barrier support 
• microbiome nourishment 
• calming 

They’re especially useful if your skin is: 

• dry 
• sensitive 
• or easily irritated 

Formulation-wise, they’re often slightly thicker (for water-based) or more spreadable and dry-touch (for oils), since you’re working over a larger surface area. 

And while actives can be included, the focus tends to shift toward comfort, consistency, and long-term support. 

Because when it comes to body care, what you use regularly matters more than what you use intensely. 

How To Formulate A “Modern” Serum (A Quick Checklist) 

 Before you finalise your serum, run through this: 

• Hydration: 

Does this formula actually hydrate the skin? On how many levels? 

• Barrier support: 

Am I supporting the skin barrier in some way? (oils, microbiome nurturing, soothing extracts) Am I hurting the skin barrier? 

• Calming / balancing: 

Is there something that helps reduce irritation or inflammation? 

• Protection: 

Am I including antioxidants or ingredients that help the skin deal with daily stress? 

• Synergy: 

Do these ingredients make sense together - or am I just adding things for the sake of it? 

• Simplicity: 

Could I remove anything and still get the same (or better) result? 

• Texture & feel: 

Does this feel good enough that someone would want to use it every day? 

• Layering: 

Does this serum leave space for the rest of a routine? 

If you can answer “yes” to most of these, you’re already formulating in a very modern, skin-supportive way. 

And just as importantly - this makes it much easier to show people everything your serum is really capable of.