Supersize Hyaluronic Acid Serum 100ml Duo | The INKEY List

Use AM and PM. On damp, cleansed skin, apply a pea-sized amount to face and neck. Gently pat in.

Follow with

Treatments → moisturiser.

Finish with SPF in your AM routine.

INKEY Tip

Apply to damp skin to lock in hydration.

Also helps other products absorb better—no pilling here.

Heads up

When adding new products to your skincare routine, we always recommend patch testing. Learn more here.

Storage

Store in a cool, dry place (15–25°C). Keep out of direct sunlight. Avoid eyes. For external use only. Keep out of reach of children.

• Clinically proven to deliver instant hydration*
• Contributes to improved skin barrier by reducing water loss*

*4-week independent clinical study of 22 people under dermatological control

**4-week independent consumer study of 22 people under dermatological control

• 2% Multi-Molecular Hyaluronic Acid: Hydration powerhouse. This moisture magnet pulls water into the skin and holds it there—helping to keep skin looking plump, smooth, and healthy. 
• Matrixyl 3000™ Peptide: Targets the look of fine lines and supports firmer-looking skin.

Water (Aqua/Eau), Propanediol, Sodium Hyaluronate, Glycerin, Butylene Glycol, Phenoxyethanol, Ammonium Acryloyldimethyltaurate/Vp Copolymer, Leuconostoc/Radish Root Ferment Filtrate, Hyaluronic Acid, Carbomer, Sodium Lactate, Polysorbate 20, Palmitoyl Tetrapeptide-7, Palmitoyl Tripeptide-1.

HOW TO USE 

WHEN SHOULD I USE THE HYALURONIC ACID SERUM? Apply morning and evening after cleansing on damp skin. It absorbs best on damp skin and creates a hydration base for every product you layer on top. Learn more about how to use it correctly →

HOW DO I USE THE HYALURONIC ACID SERUM? On cleansed, damp skin, apply 2–3 drops and gently pat in. Apply your preferred serums or treatments on top. Always follow with a moisturiser to lock in hydration. Can be used twice daily.

WHY SHOULD I APPLY IT FIRST AFTER CLEANSING? This serum absorbs best on damp skin and creates a hydration barrier for the products that follow. It also soothes skin and helps balance pH, priming your skin to get more from every step that comes next.

SHOULD I USE HYALURONIC ACID BEFORE A TONER? Yes. Applying Hyaluronic Acid before your toner helps it and every other product absorb better by working deep beneath the skin's surface.

CAN IT BE USED WITH OTHER PRODUCTS? Yes - it works with everything, including actives like Retinol and AHAs, and actually enhances the effectiveness of the products you layer on top. See what ingredients not to mix →

CAN YOU USE HYALURONIC ACID WITH VITAMIN C SERUM? Yes! Apply Hyaluronic Acid first on damp skin, wait 30–60 seconds, then apply your Vitamin C serum. HA actually helps Vitamin C absorb better and can reduce potential irritation - making it one of the most effective ingredient pairings in skincare. Read the full guide →

HOW LONG WILL IT TAKE TO SEE RESULTS? You'll feel an immediate difference in hydration from first use. Visible results - plumper, firmer, smoother skin - typically become noticeable within 4–6 weeks of consistent daily use. In our clinical study, 82% of users saw firmer, smoother skin in just 4 weeks. Consistency matters - use it twice daily, morning and evening.

HOW DO I LAYER HYALURONIC ACID AND RETINOL CORRECTLY? Apply Hyaluronic Acid first, on damp skin, immediately after cleansing. Pat in gently and wait 30–60 seconds. Then apply your retinol serum. Follow with a moisturiser to seal everything in. The HA layer creates a moisture buffer that can significantly reduce retinol irritation and dryness - making this pairing particularly effective for retinol beginners or anyone with sensitive skin. This technique is often called the "moisture sandwich method." Full guide: what not to mix with retinol →

SKIN TYPES & CONCERNS

WHO IS THE HYALURONIC ACID SERUM FOR? All skin types - especially dry, dehydrated, and mature skin needing a hydration boost. It's also suitable for sensitive skin and is pregnancy and breastfeeding safe. 5 signs you need Hyaluronic Acid Serum →

DO I NEED A MOISTURISER IF I USE HYALURONIC ACID SERUM? Yes - they do different jobs. Hydrators like Hyaluronic Acid draw water into the skin, while moisturisers lock it in. For best results, apply this serum to damp skin first, then follow immediately with a moisturiser. In dry or cold climates, skipping the moisturiser can cause HA to draw moisture from deeper skin layers rather than the air - which can worsen dryness.

WHAT IS THE DIFFERENCE BETWEEN HYALURONIC ACID SERUM AND A MOISTURISER - DO I NEED BOTH? Yes, and they work differently. Hyaluronic acid is a humectant: it draws water into the skin. A moisturiser is an occlusive or emollient: it seals that water in and prevents evaporation. Think of HA as filling the tank and moisturiser as putting the cap on. Apply this serum to damp skin, then follow immediately with a moisturiser. In dry climates or heated indoor environments, skipping the moisturiser can cause HA to draw moisture from deeper skin layers rather than the air - which can actually dry the skin out. Build your full routine →

IS HYALURONIC ACID SERUM SUITABLE FOR OILY SKIN? Absolutely - and oily skin often needs it more than people realise. Oily skin can still be dehydrated (lacking water, not oil), and dehydrated oily skin frequently overproduces sebum to compensate for the lack of moisture. Our Hyaluronic Acid Serum is water-based, oil-free, and absorbs instantly with no greasy residue - delivering hydration without contributing to congestion or shine. Why oily skin gets dehydrated too →

IS IT SAFE DURING PREGNANCY OR BREASTFEEDING? Yes. Our Hyaluronic Acid Serum is safe to use during pregnancy and breastfeeding. It contains no retinol, salicylic acid, or other ingredients considered unsuitable during pregnancy. Complete guide to pregnancy-safe skincare →

CAN I USE THIS ALONGSIDE MEDICATION? We always recommend consulting your doctor or dermatologist to be sure if you are using prescription skincare or taking medication that affects the skin.

INGREDIENTS & FORMULA

IS HYALURONIC ACID AN AHA EXFOLIANT? No. Hyaluronic Acid is a humectant - it hydrates, not exfoliates. It draws and holds water in the skin. It does not resurface, peel, or accelerate cell turnover.

WHAT PERCENTAGE OF HYALURONIC ACID DOES THIS SERUM CONTAIN? 2% Multi-Molecular Hyaluronic Acid - a blend of different molecular weights that targets hydration at multiple depths within the skin, not just the surface.

WHAT DOES THE HYALURONIC ACID SERUM ACTUALLY DO? Holds up to 1,000x its weight in water, delivering instant and lasting hydration. Clinically proven to plump skin, reduce the appearance of fine lines, and boost the effectiveness of other skincare products you layer on top. Also contains Matrixyl 3000 Peptide for additional firming benefits. Learn more about plump skin →

WHAT TYPE OF HYALURONIC ACID IS IN THIS SERUM? Multi-Molecular - meaning the formula contains HA molecules of different sizes. Larger molecules hydrate the skin's surface for instant plumping; smaller molecules penetrate deeper layers for lasting hydration.

WHAT IS THE PH LEVEL? 6.21 - close to the skin's natural pH, which means it works with your skin rather than disrupting its balance.

IS IT VEGAN? Yes - certified by The Vegan Society.

WHAT IS HYALURONIC ACID AND WHAT DOES IT ACTUALLY DO FOR SKIN? Hyaluronic acid (HA) is a molecule that occurs naturally in your skin and holds moisture - up to 1,000 times its weight in water. As we age, natural HA levels decline, leading to dehydration, dullness, and the appearance of fine lines. Topical HA serums attract water to the skin's surface and deeper layers, delivering instant plumping, improved barrier function, and a smoother complexion. Our serum uses 2% Multi-Molecular HA - different molecular sizes that target hydration at multiple skin depths. Learn more about hyaluronic acid →

WHAT IS THE DIFFERENCE BETWEEN THE INKEY LIST HYALURONIC ACID SERUM AND THE ORDINARY'S? Both are excellent affordable options. The key difference: our formula includes Matrixyl 3000 Peptide alongside the 2% Multi-Molecular HA - delivering both instant hydration and a collagen-stimulating firming benefit in a single step. This dual-action approach gives you more from one product at a comparable price point. Our formula has won the Allure Best of Beauty Award, the CEW 2023 Award, and has over 3,100 five-star reviews. At just £9, it's one of the most effective multi-functional HA serums available.

This product is;

Dermalogically tested

Clinically tested

Fragrance-free

Gluten-free

Pregnancy & Breastfeeding safe