Hyaluronic Acid

Hyaluronic Acid at Prescription Skin

Hyaluronic acid (HA) is a skin-identical hydrator that binds and holds water in the outer layers of the skin. Think of it like a tiny sponge that helps your barrier feel comfortable, bouncy and less tight. Because it is lightweight and non-comedogenic, we use it across many Prescription Skin formulas to improve tolerability, support barrier repair and soften the look of fine lines from surface dryness. HA suits most skin types, including acne-prone and sensitive skin, and it layers well with other active treatments [1].

How Hyaluronic Acid Works

Hyaluronic acid (HA) is a water-attracting molecule that behaves like a tiny sponge at the skin’s surface. It binds moisture around corneocytes (the outer skin cells), creating a lightweight “water reservoir” so the top layers stay flexible instead of tight or flaky. When these cells lie flatter and more uniform, light reflects more evenly and fine dryness lines look softer and less noticeable. By supporting the skin’s own natural moisturising factors, HA helps maintain comfortable, steady hydration through the day.

Different sizes of HA contribute in complementary ways. Larger molecules stay closer to the surface, giving quick comfort and a smooth, soft finish. Medium sizes settle within the upper epidermis to add bounce and suppleness. Smaller fractions hydrate a little deeper in the epidermis, helping that comfortable feel last longer. Many modern formulas blend multiple sizes so you get both instant relief and longer-lasting hydration.

HA also supports overall skin function. Better water balance helps the barrier work efficiently, which can reduce the look of roughness and help other skincare feel more tolerable, especially in routines that include stronger actives. The net effect is skin that appears smoother, more even, and visibly dewier as surface hydration becomes more consistent.

Skin biology and turnover

Skin continually makes and breaks down HA via synthases and hyaluronidases. Intrinsic ageing and UV exposure are associated with lower epidermal HA and altered distribution, which contributes to surface dryness and loss of snap. Topical HA does not replace deeper HA, but it can meaningfully improve surface hydration and slip between corneocytes, which translates to less roughness on clinical grading scales [1].

Molecular sizes and why they matter

Different molecular weights of hyaluronic acid behave differently on the skin. High–molecular-weight HA stays near the surface, forming a light, breathable film that delivers instant softness and eases the tight feeling after cleansing [1]. Medium–molecular-weight HA works within the upper epidermis to improve suppleness and bounce [1]. Low–molecular-weight hyaluronic acid (LMWHA) can move further into the epidermis to support longer-lasting hydration; in clinical studies using LMWHA, participants showed improvements in wrinkle depth and elasticity over 4–8 weeks compared with placebo [2]. Because very low weights can feel “active” in sensitive skin, we balance the blend for comfort.

At Prescription Skin we typically combine multiple sizes so you get quick surface comfort and a longer “reservoir” of hydration over time [1] [2].

What hyaluronic acid can help with

Dehydration and tightness:

HA pulls moisture into the outer skin layers and holds it there, so the surface feels comfortable instead of taut. With steadier hydration, micro-flaking reduces and the skin looks smoother and more flexible through the day [1].

Dullness from dryness:

When the stratum corneum is evenly hydrated, corneocytes lie flatter and light reflects more uniformly. The result is a clearer, brighter look with less of the grey, chalky cast that comes from a dry surface [1].

Fine lines from dehydration:

By building a lightweight water reservoir in the upper epidermis, HA can soften the appearance of fine, dryness-related lines. Clinical work with low-to-medium molecular weight HA has shown measurable improvements in wrinkle roughness and skin elasticity over weeks of consistent use [2] [3].

Tolerating stronger actives:

HA cushions routines that include prescription retinoids, benzoyl peroxide, or chemical exfoliants by supporting the barrier and offsetting early tightness. This comfort boost helps many people stay consistent with their treatment plan, which is where results come from [1].

Post-procedure comfort (when appropriate):

After non-ablative treatments your clinician may recommend HA-based hydrators to maintain moisture while the barrier settles. Timing and product choice should follow medical advice for the specific procedure you have had [1].

A note on healing:

In medical settings, HA dressings and gels are used on certain chronic or complex wounds. Studies suggest potential benefits for healing speed and pain compared with vehicle, although outcomes vary by wound type and product. This medical use is different from everyday cosmetic application on healthy facial skin [4].

How to apply hyaluronic acid

Start with clean, slightly damp skin

Cleanse as usual, then pat until the skin is no longer wet but still faintly damp. HA is a humectant, so a whisper of surface moisture gives it water to hold onto rather than pulling it from your skin.

Apply a thin, even layer

Use a pea-sized amount for the whole face (add a little more for neck). Spread it as a light film over cheeks, forehead, nose and chin. It doesn’t need to feel thick or sticky to work.

Seal it in

Follow with a moisturiser suited to your skin type. This “seal” reduces transepidermal water loss and locks the water HA just attracted into the outer skin layers.

Time of day and frequency

If HA is in your active, use the active at night. If you have a separate bottle of HA, you can also use it in the morning. This is because it layers easily and plays well with most other steps. If your skin is very dry or you’re in a low-humidity climate or air-conditioning, the moisturiser step becomes even more important.

How long until I start to see results?

Immediate:

Skin feels more comfortable and looks a little plumper as HA pulls water into the outer layer. Tightness after cleansing usually settles within minutes. Makeup often sits more smoothly the same day.

1 to 2 weeks:

Texture starts to feel softer and fine surface roughness looks less obvious. Any early tackiness typically settles as you fine-tune how much you use and how quickly you seal with moisturiser.

3 to 4 weeks:

Radiance improves as the surface reflects light more evenly. If you are using stronger actives like retinoids, most people notice better tolerance and fewer dry patches by this point.

4 to 8 weeks:

With low to medium molecular weight HA in a well-formulated product, studies show measurable gains in hydration, elasticity and a softening of fine dehydration lines. Results hold as long as you keep using it.

What can speed or slow progress:

Applying to slightly damp skin and sealing with moisturiser helps. Consistent morning and night use helps. Very dry or low-humidity environments need extra sealing to lock water in. Skipping moisturiser or applying to bone-dry skin can blunt results.

Side effects, what is normal and what isn’t

Most people notice only increased comfort and hydration. Occasionally, very low molecular weight HA can feel mildly active in sensitive skin. If you notice stinging or unexpected redness, apply to slightly damp skin and pair with a moisturiser. If irritation persists, contact us so your doctor can adjust your plan [1].

Who should use caution

• Compromised or highly reactive barriers: start every second day and seal with moisturiser while we assess tolerance.
• Post-procedure skin: follow your doctor’s timing on when to restart leave-on steps.
• Known excipient sensitivity: note this in your Questionnaire so we can select the right base.
• Periorificial dermatitis or active facial dermatitis: delay new leave-on steps until flares settle and we provide guidance.

FAQs

How to get started

Sign up for Prescription Skin, complete your Skin Questionnaire, and have a medical consultation to discuss your history and goals. Your doctor will prescribe a personalised Prescription Skin formula, which is compounded, packed and shipped to you. Subscribers have a two-monthly review included at no extra cost.

Is hyaluronic acid suitable for acne-prone skin

Yes. It hydrates without oil or occlusion and is non-comedogenic in our lightweight bases [1].

Should I use it on damp or dry skin

Damp. A light mist or applying straight after cleansing helps HA hold more water at the surface [1].

Can I use it twice daily

Yes. If your skin feels tight or dry, use morning and night. If you are already comfortable, once daily may be enough [1].

Will it replace my moisturiser

No. HA binds water but does not prevent water loss on its own. Seal with a moisturiser suited to your skin type [1].

Can I pair it with prescription retinoids

Yes. It is often included in retinoid plans to improve tolerance and maintain comfort, especially in the first 4 to 8 weeks [1].