Serum vs Moisturiser: Do You Need Both? The Ultimate Guide to Skincare Steps

When it comes to building a skincare routine, the question 'serum vs moisturiser: do you need both?' is one of the most common dilemmas. With so many products on the market, it's easy to feel overwhelmed and wonder if you can skip one step without sacrificing results. The short answer is: yes, you generally need both, but understanding why will transform how you care for your skin.

Serums and moisturisers serve very different purposes. A serum delivers a high concentration of active ingredients deep into the skin, targeting specific concerns like fine lines, dullness, or hyperpigmentation. A moisturiser, on the other hand, works to hydrate the skin's surface and lock in everything applied before it. Together, they create a powerful synergy that neither can achieve alone.

What Is a Serum and What Does It Do?

A serum is a lightweight, fast-absorbing liquid or gel formulated with a high concentration of active ingredients. Because serum molecules are smaller than those in moisturisers, they can penetrate deeper into the skin's layers. This makes them ideal for delivering targeted treatments such as vitamin C for brightening, retinol for anti-aging, or hyaluronic acid for intense hydration.

For example, the Glow-C Vitamin C 20% Serum is a potent antioxidant serum designed to even out skin tone and boost radiance. Similarly, the Encapsulated Retinol 3% Renewing Serum provides a powerful yet gentle way to stimulate collagen production and reduce the appearance of fine lines. Serums are typically applied after cleansing and toning, but before moisturising.

• Apply serum to slightly damp skin for better absorption.
• Use a pea-sized amount – a little goes a long way.
• Wait 30-60 seconds before layering your moisturiser on top.

What Is a Moisturiser and Why Is It Essential?

A moisturiser is a thicker, creamier product that sits on the skin's surface to hydrate, soothe, and protect. Its primary job is to seal in moisture and strengthen the skin barrier, preventing water loss and shielding against environmental aggressors. While serums treat, moisturisers maintain and defend.

Depending on your skin type, you can choose a lightweight gel-cream for oily skin or a richer formula for dry or mature skin. For instance, the Glow-C Daily Moisturiser offers a balanced, non-greasy hydration perfect for daytime use, while the Peptide Firming Night Cream works overnight to support elasticity and repair. Moisturisers also often include ingredients like ceramides, peptides, or squalane to support barrier function.

• Always apply moisturiser after your serum to lock in active ingredients.
• Choose a formula suited to your skin type – gel for oily, cream for dry.
• Don't forget your neck and décolletage – they need hydration too.

Do You Really Need Both? The Science of Layering

Think of your skincare routine like a sandwich. The serum is the filling – the concentrated, targeted treatment. The moisturiser is the bread – it holds everything together and prevents the good stuff from evaporating. Without a moisturiser, the active ingredients in your serum may not work as effectively, and your skin could become dehydrated or irritated.

Research shows that applying a moisturiser after a hydrating serum can increase skin hydration levels by up to 30% compared to using a serum alone. This is because moisturisers contain occlusive ingredients like shea butter or oils that create a protective seal. On the flip side, using only a moisturiser means missing out on the high-dose actives that serums provide. For example, you can't get the same brightening effect from a moisturiser as you would from a dedicated vitamin C serum.

• Layer from thinnest to thickest: serum first, then moisturiser.
• Allow each product to absorb before applying the next.
• If you have oily skin, use a lightweight serum and a gel-based moisturiser.

How to Choose the Right Serum and Moisturiser for Your Skin Type

Your skin type and concerns should guide your product choices. For dry or dehydrated skin, look for a hydrating serum containing hyaluronic acid or glycerin, paired with a rich moisturiser that includes ceramides or squalane. The HydraOat Soothing Daily Moisturiser is an excellent option for sensitive or compromised barriers, as it calms irritation while providing long-lasting hydration.

For oily or acne-prone skin, choose a lightweight, non-comedogenic serum like the Blemicalm Azelaic Acid 15% Clarifying Serum, which helps reduce breakouts and redness. Follow it with an oil-free moisturiser that won't clog pores. Those targeting signs of aging should consider the Retinol Firming Moisturiser 0.3%, which combines the benefits of a serum-strength retinol with moisturising ingredients, streamlining your routine without sacrificing results.

• Dry skin: hydrating serum + rich cream moisturiser.
• Oily skin: clarifying serum + gel or water-based moisturiser.
• Mature skin: anti-aging serum + firming night cream.

Ultimately, both a serum and a moisturiser play distinct yet complementary roles in a complete skincare routine. While a serum delivers potent active ingredients to target your specific concerns, a moisturiser seals in hydration and protects your skin barrier. Skipping either step means leaving results on the table. If you're ready to upgrade your routine, explore the Glow-C Daily Moisturiser – a lightweight, brightening moisturiser that pairs beautifully with any serum for a radiant, healthy complexion.