Hyaluronic serum: effect, application and the best products

Hyaluronic serum is the best-selling skin care product in the world – and for good reason. Hyaluronic acid binds up to 1,000 times its own weight in water and plumps up the skin from the inside. If you don’t yet have a serum in your daily routine, you are missing out on real potential.

What does hyaluronic acid do in the skin?

Hyaluronic acid (HA) occurs naturally in the skin – and decreases dramatically with age. At 25, the skin still produces enough, but by 40 the level has fallen by over 50%. When applied as a serum, it penetrates into the upper layers of the skin and provides:

• Intensive hydration: Immediate moisture boost, visible after the first application
• Volume effect: fine lines are plumped up by moisture
• Barrier strengthening: the skin barrier is stabilized, less transepidermal moisture loss
• Soothing: Hyaluronic acid is suitable for all skin types, including rosacea skin

Low molecular weight vs. high molecular weight: Which is better?

This is the most common question when buying hyaluronic serums. In the K-Beauty world, many brands already rely on multi-weight formulas:

• High molecular weight HA (over 1,000 kDa): Stays on the skin surface, acts as a moisture-binding film – quick visible shine effect
• Low molecular weight HA (less than 500 kDa): Penetrates deeper into the skin, more effective in the long term
• Multi-weight HA: combination of both molecule sizes – the smartest option. Most high-quality serums today rely on

The best hyaluronic serums in comparison

Budget (under 20 Euro)

• The Ordinary Hyaluronic Acid 2% + B5 (~8 euros): Reliable, well formulated, ideal for beginners
• Garnier Hyaluron Filler Serum (~15 euros): Widely available, for dry and normal skin
• COSRX Hyaluronic Acid Intensive Cream (~18 euros): More of a cream than a serum, but hugely hydrating

Mid-range (20-60 euros)

• Vichy Liftactiv Supreme H.A. Epidermic Filler (~35 euros): Dermatologically tested, 1.5% HA concentration
• La Roche-Posay Hyalu B5 Serum (~42 euros): Gold standard for sensitive skin – Bakuchiol plus HA
• Paula’s Choice Hyaluronic Acid Booster (~52 euros): Multi-weight formula, excellent tolerance

Premium (over 60 euros)

• SkinCeuticals H.A. Intensifier (~115 euros): Clinically tested, 1.3% HA with Proxylane and Licorice Root
• Drunk Elephant B-Hydra Intensive Hydration Serum (~75 euros): Light, layerable, ideal for combination skin

Application: When and how to apply?

Hyaluronic serum works best on slightly moist skin – this increases penetration. A common mistake is to apply it to completely dry skin – HA then draws moisture from the skin instead of from the outside. Further tips for optimal integration into the Glass Skin morning routine:

1. Cleanse face
2. Apply toner or essence – leave slightly damp
3. Press on hyaluronic serum (do not rub in – gently tap in)
4. Moisturizing cream over it – seals the HA
5. SPF in the morning

Combination with other active ingredients

Hyaluronic acid is compatible with almost everything. Good combinations:

• HA + niacinamide: hydration plus pore refinement – classic K-Beauty combination
• HA + vitamin C: layer serum in the morning, vitamin C underneath or on top
• HA + retinol: apply HA before retinol – buffers irritation and keeps skin moisturized