50ml full size, 15ml travel size
ESK · PHA serum
Gentle Glow
ESK Gentle Glow · a PHA serum with gluconolactone 5% and lactobionic acid 5%
The exfoliant for skin that cannot use exfoliants. A serum built on two polyhydroxy acids, gluconolactone 5% and lactobionic acid 5%, at pH 4.3 to 4.8: large molecules that loosen dead surface cells slowly and gently while hydrating and acting as antioxidants. Made for sensitive, dry, red and rosacea-prone skin, and suitable for all skin types, including deeper skin tones (Fitzpatrick V to VI).
- Two PHAs at 5% each, the strength ESK says the evidence supports, for the look of smoother, brighter skin without the sting of an AHA.
- Hydrates as it exfoliates, and ESK says PHAs may reduce irritation from other products in a routine.
- Night, before your night cream. Can also go under moisturiser in the morning. Fragrance-free, non-comedogenic.
- The exfoliating step in the Rosacea Kit, and the one we pair with a first retinal.
3 to 4 months from the full size at nightly use
PHAs are the acids we reach for first on reactive skin and deeper skin tones, because the failure mode of a stronger acid there is a dark mark. The 15ml for £35 is enough to know whether your skin agrees.
Free UK delivery over £65 · Tracked £3.49 · Sent tracked, 2 to 4 working days
- Good to know
- No fragrance or essential oils in the ingredient list. ESK reports a slight tingle can happen on first use.
- Stockist
- Melatone Skin Clinic is an authorised ESK stockist. Genuine product with full traceability.
If it stings for more than a few seconds or your skin goes red, drop to every second night, then stop if it continues. A PHA is the gentlest acid there is, so persistent stinging usually means the barrier needs a few weeks of Repair + first. Message us.
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 PHA serum, honestly
Most people who reach for it have been told they cannot exfoliate: their skin is red, dry, reactive or rosacea-prone, and every acid they have tried has stung. Polyhydroxy acids are the answer to that. The molecules are larger than glycolic or lactic acid, so they get into the skin more slowly, exfoliate the surface gently, and hold water at the same time.
What it will not do is work as fast as a glycolic serum. Skin looks brighter within a couple of weeks, but the texture and tone changes are gradual, and that is the trade. If your skin is not sensitive and you want speed, Smooth Serum is the AHA version of this step.
On deeper skin tones, a PHA is often the right first acid regardless of sensitivity, because the risk with stronger acids there is irritation turning into dark marks. ESK also notes that PHAs may reduce irritation from other products, which is why we pair Gentle Glow with a first retinal.
Quick facts
- What it is
- A polyhydroxy acid (PHA) exfoliating serum that also hydrates.
- Sizes
- 50ml (£69.00, around 3 to 4 months) and 15ml travel size (£35.00, around 3 to 4 weeks).
- Best for
- Sensitive, dry, red and rosacea-prone skin that wants smoother, brighter-looking skin without irritation.
- Skin types
- Suitable for all skin types, especially dry to normal, including deeper skin tones (Fitzpatrick V to VI).
- Key ingredients
- Gluconolactone 5%, lactobionic acid 5%, glycerin, camellia seed oil, vitamin E.
- pH
- 4.3 to 4.8.
- How to use
- 1 to 2 pumps at night, after cleansing, before night cream. Start every second night. Can also go under morning moisturiser.
- Free from
- Fragrance, essential oils, parabens and sulphates. Non-comedogenic.
- Daily SPF
- Recommended with any exfoliant.
- Pregnancy
- Ask your midwife, GP or pharmacist before using a leave-on acid; PHAs are the gentlest class.
Where it fits in a routine
Night: Calming Cleanse, Gentle Glow, then your night cream, such as Repair + or B Quenched, or a gentle retinal such as Ultimate A once you are settled.
Morning, optional: Gentle Glow under your day moisturiser, then SPF such as Zinc Shade.
It is the exfoliant in the Rosacea Kit and in our version of the Pigmentation Kit. Skin that is not sensitive and wants a faster result: Smooth Serum, the AHA version of this step.
The detail
Ingredients, and what each one does
- Gluconolactone (PHA), 5%
- A large-molecule polyhydroxy acid. Exfoliates the surface gently, holds water, and acts as an antioxidant. Tolerated by rosacea-prone and sensitive skin in studies. Widely studied.
- Lactobionic acid (PHA), 5%
- A polyhydroxy bionic acid with the same gentle exfoliation plus strong water-binding. Widely studied.
- Glycerin
- A humectant that holds water in the surface layers.
- Camellia seed oil, soybean oil
- Light plant oils that keep the serum comfortable.
- Vitamin E (tocopherol), carrageenan extract
- An antioxidant and a conditioning agent included in the formula.
Lactobionic acid 5% and gluconolactone 5% as printed on the ESK pack; pH 4.3 to 4.8 as published by ESK. Descriptions are about the look and feel of skin, not a medical outcome.
Full ingredients (INCI): Water/Aqua, Butylene Glycol, Lactobionic Acid, Gluconodeltalactone, Glycerin, Chondrus Crispus Extract, Camellia Oleifera Seed Oil, Tocopherol, Benzyl Alcohol, Glycine Soja (Soybean) Oil, Dehydroacetic Acid, Sodium Hydroxide, Disodium EDTA.
How to use it
Night
- Cleanse and pat dry.
- Put 1 to 2 pumps of Gentle Glow on your fingertips and smooth over the face and neck.
- Let it settle for a minute.
- Follow with your night cream or retinal.
Building up
Week 1: every second night. Then nightly if your skin is comfortable, per ESK. Most sensitive skin gets to nightly; some stays at alternate nights, which is fine.
Morning, optional
It can also go under your moisturiser in the morning, then SPF.
Beyond the face
Décolletage, the backs of the hands and the forearms.
What to expect, and when
- First use
- A light serum that absorbs cleanly. A slight tingle on first use is normal, per ESK; stinging that lasts is not.
- 1 to 2 weeks
- Skin looks brighter and feels smoother and better hydrated.
- 4 to 8 weeks
- The point to judge texture and the look of surface tone.
- If nothing has changed
- PHAs are gradual by design. If your skin is not sensitive, Smooth Serum is the faster step. Message the clinic.
Is it right for my skin
- Sensitive and reactive skin
- Yes. This is the acid built for it.
- Rosacea-prone skin
- Yes, per ESK. Introduce every second night, and pause during a flare.
- Dry and dehydrated skin
- Yes. It hydrates as it exfoliates.
- Deeper skin tones (Fitzpatrick V to VI)
- Yes. Often the right first acid on deeper skin, where stronger acids risk marks.
- Anyone starting a first retinal
- Yes. ESK notes PHAs may reduce irritation from other products.
- Oily, non-sensitive skin wanting speed
- Smooth Serum or Ultimate A+ do more, faster.
- A damaged barrier right now
- Wait. A few weeks of Repair + first, then Gentle Glow.
- Pregnancy or breastfeeding
- Ask your midwife, GP or pharmacist; PHAs are the gentlest acid class, and ESK publishes no specific guidance.
Using it with what you already own
- Ultimate A (retinal)
- Yes. Gentle Glow first, Ultimate A over it. Introduce on separate nights, then combine.
- Ultimate A Gold
- Usually unnecessary: it already carries lactobionic acid 5%. ESK notes Gentle Glow's 10% total PHA is the stronger PHA step if you want more.
- Smooth Serum
- Not on the same night. One exfoliating serum at a time.
- Vitamin C
- Yes: vitamin C in the morning, Gentle Glow at night.
- Niacinamide moisturisers
- Yes. Gentle Glow first, then B Quenched, Repair + or Enlighten Gold.
- After in-clinic treatments
- Pause it for as long as your practitioner advises, then reintroduce every second night.
Questions we actually get asked
What is ESK Gentle Glow?
A serum with two polyhydroxy acids, gluconolactone 5% and lactobionic acid 5%, at pH 4.3 to 4.8, that exfoliates the surface gently while hydrating. It is ESK's exfoliant for sensitive, dry and rosacea-prone skin, used at night before your night cream.
What is a PHA?
A polyhydroxy acid, the gentlest class of exfoliating acid. PHAs such as gluconolactone and lactobionic acid have larger molecules than AHAs, so they move into the skin more slowly, exfoliate the surface gently, and also hold water and act as antioxidants.
PHA vs AHA vs BHA: what is the difference?
AHAs (glycolic, lactic) are small, fast surface exfoliants. A BHA (salicylic acid) is oil-soluble, which is why it is used for oily skin. PHAs are larger, slower and hydrating, and are the class tolerated by sensitive and rosacea-prone skin. Gentle Glow is the PHA; Smooth Serum the AHA; Hydroxy Cleanser and B Calm carry the BHA.
Is it good for sensitive skin?
Yes. It is the ESK exfoliant built for sensitive and reactive skin: fragrance-free, no essential oils, and acids gentle enough that ESK lists it as rosacea-friendly.
Is it good for rosacea?
ESK lists it as rosacea-friendly and it is the exfoliating step in ESK's rosacea routine. Introduce it every second night, pause it during a flare, and see your GP about the rosacea itself.
Can I exfoliate if I have sensitive skin?
With a PHA, usually yes. That is the point of Gentle Glow. If your barrier is currently damaged (tight, flaky, stinging), spend a few weeks on a barrier cream first, then start every second night.
How do I use it?
1 to 2 pumps at night on clean, dry skin, then your night cream. Every second night for the first week, then nightly if comfortable. It can also go under your moisturiser in the morning.
How often should I use it?
Nightly once your skin is used to it, per ESK. Sensitive skin can stay at every second night.
Does it tingle?
ESK says a slight tingle can happen on first use. Stinging that lasts, or redness, means drop to every second night or pause.
Can I use it with a retinal?
Yes, and it is the pairing we suggest for a first retinal. ESK notes that PHAs may reduce irritation from other products. Gentle Glow first, then Ultimate A. Introduce them on separate nights, then combine.
Can I use it with Ultimate A Gold?
You can, but it is usually unnecessary: Ultimate A Gold already carries lactobionic acid 5%. ESK notes Gentle Glow's 10% total PHA is the stronger PHA step if you want more exfoliation.
Can I use it with vitamin C?
Yes: vitamin C in the morning, Gentle Glow at night.
Can I use it with niacinamide?
Yes. Gentle Glow first, then a niacinamide moisturiser such as B Quenched or Repair +.
Can I use it with Smooth Serum or another acid?
Not on the same night. One exfoliating serum at a time. Most people choose one or the other.
Do I need SPF with it?
Yes, every morning. PHAs increase sun sensitivity less than AHAs, but daily SPF is the rule with any exfoliant.
Is it suitable for deeper skin tones?
Yes. It is suitable for all skin types, including deeper skin tones (Fitzpatrick V to VI), and a PHA is often the right first acid there, because stronger acids rushed can leave marks.
Does it help with dark marks and uneven tone?
Gentle, regular exfoliation supports the look of surface tone over weeks. It is a supporting step: for marks as the main concern, add daily SPF and a tone-evening active such as Enlighten Gold.
Is it suitable for oily or acne-prone skin?
Yes, it is non-comedogenic. If congestion is the main concern, a salicylic acid step (B Calm) or Ultimate A+ does more.
Can I use it in pregnancy or breastfeeding?
PHAs are the gentlest acid class, and ESK publishes no specific guidance. Ask your midwife, GP or pharmacist before using any leave-on acid.
Does it contain fragrance?
No. No fragrance or essential oils appear in its ingredient list, and it is free from parabens and sulphates.
How long does it take to work?
Brighter, smoother-feeling skin within 1 to 2 weeks. Texture and the look of surface tone take 4 to 8 weeks.
What is the difference between Gentle Glow and Smooth Serum?
Gentle Glow is a PHA serum (gluconolactone 5%, lactobionic acid 5%), gentle, hydrating and fragrance-free, for sensitive skin. Smooth Serum is an AHA serum (glycolic 3%, lactic 1%), faster and stronger, with essential oils, for skin that is not sensitive.
How long does a bottle last?
The 50ml lasts around 3 to 4 months of nightly use, and longer at every second night. The 15ml travel size lasts around 3 to 4 weeks.
Is it cruelty free and vegan?
Yes. ESK states that Gentle Glow 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 exfoliant 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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