50ml full size, 15ml travel size
ESK · Hyaluronic acid serum
Hydraboost
ESK Hydraboost · a hyaluronic acid serum with three molecular weights and panthenol
A light hydrating serum built on hyaluronic acid 1.6% in three molecular weights, high (0.7%), medium (0.7%) and low (0.2%), with panthenol 1.5%, at pH 5 to 5.5. It goes on first, under serums and moisturiser, morning and night, for skin that feels tight, dehydrated or dull. Suitable for all skin types, including deeper skin tones (Fitzpatrick V to VI).
- Three weights of hyaluronic acid: the larger sits on the surface for immediate smoothness, the smaller sink further in.
- Panthenol 1.5% (provitamin B5) supports the barrier and helps skin hold water.
- The first step after cleansing, morning and night. Layers under vitamin C, retinal and moisturiser.
- Patch test first: ESK reports rare cases of sensitivity and flaking. No essential oils.
3 to 4 months of morning and night use
A hyaluronic serum earns its place by making everything over it more comfortable: it is the step that lets dry or reactive skin tolerate a retinal or a vitamin C. Try the 15ml for £32 if you want to test that first.
Free UK delivery over £65 · Tracked £3.49 · Sent tracked, 2 to 4 working days
- Good to know
- ESK reports rare cases of sensitivity and flaking, so patch test before first use. Apply to damp skin and seal with moisturiser: hyaluronic acid on bare skin in dry air can pull water the wrong way.
- Stockist
- Melatone Skin Clinic is an authorised ESK stockist. Genuine product with full traceability.
If your skin flakes or stings, stop, and message us. It is uncommon with a hyaluronic serum, but ESK has had reports, and the fix is usually a different hydrator rather than pushing on.
Not sure if this is right for your skin? Message us on WhatsApp or book a skin assessment and we will confirm the right routine first.
A hyaluronic acid serum, honestly
Most people who reach for it have skin that feels tight after cleansing, looks dull, or cannot tolerate the actives they want to use. A hyaluronic serum is the fix for that: it draws water into the surface layers so skin looks plumper and feels comfortable, and it makes the retinal or vitamin C that goes over it easier to live with.
What it will not do is treat oily skin's oil, dry skin's lack of oil, or pigmentation. It is water, not treatment. Oily skin still needs a moisturiser over it (a light one); dry skin needs a richer cream over it; and the plumped look is a same-day effect that lasts as long as you keep using it.
Three weights matter because hyaluronic acid does different things at different sizes: the large molecule sits on the surface and smooths, the smaller ones reach further in. ESK also notes the smaller weights are studied for the look of fine lines. It is a supporting step in every routine we build, not the star of any.
Quick facts
- What it is
- A hyaluronic acid hydrating serum, the first step after cleansing.
- Sizes
- 50ml (£63.00, around 3 to 4 months) and 15ml travel size (£32.00, around 3 to 4 weeks).
- Best for
- Skin that feels tight, dehydrated or dull, and anyone using actives that dry the skin.
- Skin types
- Suitable for all skin types, including deeper skin tones (Fitzpatrick V to VI), oily, dry, sensitive and menopausal skin.
- Key ingredients
- Hyaluronic acid 1.6% in three weights (0.7% high, 0.7% medium, 0.2% low), panthenol 1.5%.
- pH
- 5.0 to 5.5.
- How to use
- 1 to 2 pumps on damp skin, first step after cleansing, morning and night, then seal with moisturiser.
- Free from
- Essential oils, parabens and sulphates.
- Patch test
- Yes: ESK reports rare sensitivity and flaking.
- Pregnancy
- Hyaluronic acid and panthenol are widely regarded as suitable; ESK publishes no specific guidance. Ask if unsure.
Where it fits in a routine
Morning: cleanse, Hydraboost on damp skin, then a vitamin C such as C Forte if you use one, then moisturiser, then SPF such as Zinc Shade.
Night: cleanse, Hydraboost, then your night cream or retinal, such as Ultimate A or Ultimate A Gold. Under a retinal it is the step that stops dryness.
Dry or reactive skin: Hydraboost, then Repair + or B Quenched. Oily skin: Hydraboost, then B Calm.
The detail
Ingredients, and what each one does
- Hyaluronic acid, high molecular weight, 0.7%
- A large molecule that stays on the surface, holds water there and gives an immediate smoother, plumper feel. Widely studied.
- Hyaluronic acid, medium molecular weight, 0.7%
- Sits between the two, adding hydration a little deeper into the surface layers.
- Hyaluronic acid, low molecular weight, 0.2%
- A smaller molecule that reaches further into the surface layers. ESK notes studies suggesting the low weight supports the look of fine lines.
- Panthenol (provitamin B5), 1.5%
- A humectant that supports the skin barrier and helps reduce water loss, and is soothing on irritated skin. Widely studied.
- Propanediol, pentylene glycol, macadamia glycerides
- Solvents and light emollients that carry the hyaluronic acid and keep the serum comfortable.
Hyaluronic acid 1.6% and panthenol 1.5% as printed on the ESK pack; the three-weight split and pH 5 to 5.5 as published by ESK. Descriptions are about the look and feel of skin, not a medical outcome.
Full ingredients (INCI): Water/Aqua, Propanediol, Pentylene Glycol, PEG-16 Macadamia Glycerides, Sodium Hyaluronate, Panthenol, Caprylyl Glycol, Benzyl Alcohol, Sodium Phytate, Alcohol, Dehydroacetic Acid.
How to use it
Morning and night
- Cleanse, and leave the skin slightly damp.
- Put 1 to 2 pumps of Hydraboost on your fingertips and press over the face and neck.
- Let it settle for a minute.
- Follow with any active serum, then moisturiser, and SPF in the morning.
Order
First after cleansing, always. ESK's instruction is Hydraboost first, then the rest of the routine. It is the thinnest step, so anything applied before it would block it.
Beyond the face
Neck, décolletage and the backs of the hands, wherever skin feels dry.
Starting out
Patch test on the inner forearm for 24 to 48 hours first. ESK reports rare cases of sensitivity and flaking.
What to expect, and when
- First use
- Skin feels smoother and less tight straight away. The effect lasts as long as you keep using it.
- First 2 weeks
- Skin looks plumper and less dull, and actives over it feel more comfortable.
- 4 to 8 weeks
- The point to judge the look of fine dehydration lines.
- Flaking or stinging
- Uncommon, but reported. Stop and message us.
Is it right for my skin
- Dehydrated skin of any type
- Yes. This is who it is made for.
- Oily skin that feels tight
- Yes. Oily skin can still lack water; use it under a light moisturiser such as B Calm.
- Dry skin
- Yes, under a richer cream such as Repair + or B Quenched.
- Sensitive and rosacea-prone skin
- Yes. No essential oils. Patch test first.
- Deeper skin tones (Fitzpatrick V to VI)
- Yes.
- Menopausal skin
- Yes. ESK lists it.
- Anyone starting a retinal or a vitamin C
- Yes. It is the step that makes them easier to tolerate.
- Pregnancy or breastfeeding
- Widely regarded as suitable; ESK publishes no specific guidance. Ask if unsure.
Using it with what you already own
- Vitamin C
- Yes. Hydraboost first, then C Forte or C Lite, then moisturiser.
- Retinal or retinol
- Yes. Hydraboost first, then the retinal. It reduces dryness.
- Niacinamide
- Yes. Hydraboost first, then B Calm, B Quenched or Repair +.
- Exfoliating acids
- Yes. Hydraboost first, then the acid serum, then moisturiser. If in doubt, put the acid on dry skin and Hydraboost after it.
- Moisturiser
- Always over it. Hyaluronic acid on its own in dry air can leave skin feeling drier.
- After in-clinic treatments
- Often useful, but follow the aftercare you were given and check before applying anything to treated skin.
Questions we actually get asked
What is ESK Hydraboost?
A hydrating serum with hyaluronic acid 1.6% in three molecular weights and panthenol 1.5%, at pH 5 to 5.5. It is used first after cleansing, morning and night, under the rest of your routine.
What does hyaluronic acid do for skin?
It binds water. In a serum it draws water into the surface layers of the skin, which makes skin feel smoother and look plumper and less dull. It does not add oil, so it suits every skin type, and the effect lasts as long as you keep using it.
Why three molecular weights?
Hyaluronic acid comes in different molecule sizes. The large molecule stays on the surface and smooths; the smaller ones reach further into the surface layers. ESK combines high, medium and low weights so it works at more than one level.
Is hyaluronic acid good for oily skin?
Yes. Oily skin can still be short of water, especially if you use acids or a retinal. Hydraboost adds water without oil; put a light moisturiser such as B Calm over it.
Is it good for dry skin?
Yes, as the water step. Dry skin also needs oil and barrier lipids, so follow it with a richer cream such as Repair + or B Quenched.
How do I use it?
1 to 2 pumps on damp skin straight after cleansing, morning and night. Let it settle, then apply your serums, moisturiser and, in the morning, SPF.
Should I apply it to wet or dry skin?
Slightly damp. Hyaluronic acid draws water from wherever it can; on damp skin it holds that water in place, and a moisturiser over it seals it.
Hyaluronic acid or niacinamide first?
Hydraboost first. It is the thinnest step. Niacinamide moisturisers such as B Calm and Repair + go over it.
Hyaluronic acid or vitamin C first?
Hydraboost first, then vitamin C, then moisturiser. If your vitamin C stings on damp skin, let Hydraboost dry fully first.
Retinol or hyaluronic acid first?
Hydraboost first, then the retinal. It reduces the dryness a retinal can cause.
Can I use hyaluronic acid with retinol?
Yes, and it is one of the best pairings for tolerance. Hydraboost under Ultimate A, Ultimate A+ or Ultimate A Gold at night.
Can I mix it with vitamin C?
Use them in sequence rather than mixing them in your hand: Hydraboost, then the vitamin C serum.
How often should I use it?
Twice a day is the standard. Once a day is fine if your skin is not particularly dehydrated.
Does hyaluronic acid help with acne?
Not directly. It hydrates without oil, which helps acne-prone skin tolerate the treatments that do the work. B Calm and Hydroxy Cleanser are the breakout steps.
Does it help with fine lines?
Dehydration lines look softer when the skin is properly hydrated, which is a same-day effect. ESK also notes that low-molecular-weight hyaluronic acid is studied for the look of fine lines. For structural lines, a retinal is the step.
Can it make my skin feel drier?
It can, if it is applied to bone-dry skin in dry air with nothing over it: the hyaluronic acid pulls water from the skin instead of the air. Apply to damp skin and seal with moisturiser.
Is it suitable for sensitive skin?
Yes. It contains no essential oils and ESK lists sensitive skin. Patch test first: ESK reports rare cases of sensitivity and flaking.
Is it suitable for deeper skin tones?
Yes. It is suitable for all skin types, including deeper skin tones (Fitzpatrick V to VI).
Can I use it in pregnancy or breastfeeding?
Topical hyaluronic acid and panthenol are widely regarded as suitable in pregnancy, and ESK publishes no specific guidance. Ask your midwife, GP or pharmacist if unsure.
Does it contain fragrance?
No fragrance or essential oils appear in its ingredient list. It is free from parabens and sulphates.
How long does it take to work?
Skin feels smoother straight away. Give it 2 weeks to judge plumpness and dullness, and 4 to 8 weeks for the look of fine dehydration lines.
Is it an oil-free serum?
It contains no plant oils. Macadamia glycerides, a light emollient derived from macadamia oil, are present at a low level to keep the serum comfortable.
What is the difference between Hydraboost and Repair +?
Hydraboost is a water-based hyaluronic serum, the hydration step. Repair + is a moisturiser with niacinamide, ceramides and panthenol, the barrier step. Dry skin often uses both, in that order.
How long does a bottle last?
The 50ml lasts around 3 to 4 months of twice-daily use. The 15ml travel size lasts around 3 to 4 weeks.
Is it cruelty free and vegan?
Yes. ESK states that Hydraboost is cruelty free and vegan.
Is Melatone an authorised ESK stockist?
Yes. Melatone Skin Clinic is an authorised ESK stockist. Stock comes directly from ESK, so every item is genuine and traceable, and it is the same product we use in clinic.
Can someone help me work out whether this is right for me?
Yes. Message us on WhatsApp with a description of your skin, or book a skin assessment at the clinic in Battersea.
What is the delivery and returns position?
Tracked UK delivery is £3.49, or free over £65, and usually arrives in 2 to 4 working days. Sealed, unopened items can be returned within 60 days for a refund.
Buying it from Melatone
Melatone Skin Clinic is an authorised ESK stockist. Stock is bought directly from ESK, so every item is genuine and traceable, and it is the same product we use in clinic in Battersea, London.
If you are not sure this is the right hydration step for your skin, do not guess. Message us on WhatsApp or book a skin assessment, and we will suggest a routine before you buy.
Delivery
Tracked UK delivery, £3.49 or free over £65. It usually arrives within 2 to 4 working days, with tracking by email. The price you see is the price you pay, with any delivery charge shown in full before checkout.
Returns
Sealed, unopened items may be returned within 60 days of receiving your order for a refund. For hygiene reasons we cannot accept returns of skincare once any seal has been opened, unless faulty. Your statutory 14-day right to cancel is unaffected.
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