Thirty minutes after applying a hyaluronic acid serum, skin hydration exceeded that of simply cleansed skin by 17.8%, in a randomized trial of 123 volunteers. Eight hours later, the serum alone was no longer significantly better than the control; followed by a cream, it remained superior. The entire challenge lies here: an active ingredient that attracts water very quickly, a routine that must retain it.
This guide brings together what studies identified via PubMed show: mechanism of action, molecular weight, results and timelines, format according to your skin type, application and complementary actives. A typical routine, morning and evening, concludes the article.
What it does : hyaluronic acid is a humectant capable of binding up to 1,000 times its volume in water. On skin, it acts mainly in the stratum corneum: forms of 20 to 300 kDa penetrate it in an ex vivo study, heavier forms remain on the surface and form a film. Trials measure increased hydration within 30 minutes, then slightly less deep wrinkles after 30 to 60 days. Nothing comparable to an injection, which adds volume to the tissues.
How to use it : a few drops on clean skin, morning and evening, then a cream on top; only this routine maintained hydration superior to the control 8 hours later (+11.4%). Vitamin C, niacinamide and retinol have their own trials, and daily sunscreen remains the best-proven ally: 24% less skin aging in 4.5 years in 903 adults, compared to occasional use.
- How hyaluronic acid hydrates the skin
- What it doesn't do: fill a furrow
- Molecular weight: what penetrates, what stays on the surface
- What trials measure, and over what timeframe
- Serum, cream, gel or mask: what are the differences?
- Which format for your skin type
- Choosing wisely: form, complementary ingredients, tolerance
- How to apply a hyaluronic acid serum
- What to combine it with: vitamin C, niacinamide, retinol, sunscreen
- The typical routine, morning and evening
- Pregnancy, reactive skin: precautions
- And orally?
- Frequently asked questions
How hyaluronic acid hydrates the skin
Hyaluronic acid is a very long sugar from the glycosaminoglycan family. The skin concentrates about half of the body's supply, mainly in the dermis. It binds up to 1,000 times its volume in water, according to two reviews dedicated to its cosmetic use, and renews very quickly: its half-life in the skin is less than one day, and a 70 kg adult contains approximately 15 g, of which 5 g are replaced each day.
With age, it gradually disappears from the epidermis to be found only in the dermis: this is the most marked change observed in aging skin, and a 2022 review places the start of hyaluronic acid loss around age 25. Researchers link it to dryness, loss of elasticity, and fine lines in mature skin.
Applied to the skin, it acts as a humectant : it attracts water toward the stratum corneum, from the ambient air and from deeper layers, especially from the latter when air humidity drops below 80%, notes a review dedicated to moisturizers. Large molecules do not penetrate: they hydrate the most superficial cells and form a film that slows evaporation, hence a reduction in transepidermal water loss, the water that passively escapes through the stratum corneum.
This is also its limitation: applied alone, a humectant can increase water loss through the epidermis, and the same review recommends combining it with an occlusive, a fatty substance that covers the surface. A healthy stratum corneum contains 15 to 25% water at the surface and approximately 40% at its deeper limit.
<<<21>>> Humectants humectants (hyaluronic acid, glycerin, urea) attract water toward the epidermis. Emollients integrate into the stratum corneum and soften it. Occlusives (vaseline, dimethicone, plant oils, waxes) cover the surface and slow evaporation. A serum focuses mainly on the first family, a cream on the other two.
What it does not do: fill a deep line
The same word covers two very different products. Injections use a hyaluronic acid gel intended to restore soft tissue volume; according to a systematic review, these filler products, the most commonly used, are surrounded by a fibrous capsule and induce limited production of new collagen. The procedure, its risks, and the decision are the responsibility of a doctor.
Applied as a serum or cream, hyaluronic acid acts mainly in the superficial layers. In volunteers applying daily a formula combining high and low molecular weights, the amount measured in the stratum corneum was at least 8 times higher than before 24 hours after the first application, and at least 31 times after seven applications; the method did not allow measurement of the deep epidermis or dermis. A 2021 review sums it up: high molecular weight forms do not penetrate deeply, and their benefits remain those of a surface treatment.
In the most favorable trial presented below, the average depth of crow's feet wrinkles decreased from 338.7 to 265.1 µm in 30 days, a smoothing of a few hundredths of a millimeter, while it remained stable under placebo. No trial shows that a skincare product corrects a deep line or volume loss like an injection: this is a question to ask a doctor.
Molecular weight: what penetrates, what stays on the surface
The mass of hyaluronic acid is expressed in kilodaltons (kDa): from 1 to 2,000 kDa in the products from the trials cited here. The skin produces long chains, approximately 600 to 1,200 kDa, and short chains, approximately 5 to 50 kDa, according to a 2022 review, which adds that short forms can exceed the stratum corneum. Now size determines penetration.
On ex vivo human skin, low molecular weight hyaluronic acid, 20 to 300 kDa, crossed the stratum corneum, while the high molecular weight form, 1,000 to 1,400 kDa, did not cross it.
Essendoubi M, Gobinet C, Reynaud R, et al. Skin Res Technol 2016;22(1):55-62. DOI: 10.1111/srt.12228
Long forms have other advantages: they thicken the formula and form a viscoelastic film that slows evaporation. Hence the multi-molecular weight formulas: the 2014 trial detailed below combined five sizes, from 1 to 2,000 kDa, and a cross-linked form.
Smaller doesn't mean better in everything. In biology, short fragments can have pro-inflammatory activity, notably described during wound healing, while long chains tend to help control inflammation. In the clinical trials reviewed here, however, no irritation was attributed to short forms, and no adverse effects were observed over 4 weeks in 36 people aged 60 to 80 years. The ingredient list does not indicate molecular weight; in the 2014 trial, the so-called hydrolyzed forms weighed 5 and 50 kDa.
What the trials measure, and over what timeframe
These trials are often small, short, and funded by the manufacturers of the tested products. The most consistent effect is hydration, then elasticity, and more variably, wrinkle depth. A 2021 review notes that the link between hydration and wrinkles is not entirely established, and a 2022 review, written by employees and a consultant of a cosmetic group, calls for longer and better-controlled studies.
Immediate effect. In a trial of 123 volunteers with dry or normal skin, a serum with 1% sodium hyaluronate increased hydration by 17.8% at 30 minutes compared to skin that was only cleansed, like a cream (17.7%), and reduced insensible water loss by 14.6%. Eight hours later, it performed no significantly better than the control.
After 4 to 8 weeks. In women with wrinkles around the eyes, creams containing 0.1% sodium hyaluronate of 50 to 2,000 kDa all improved hydration and elasticity in 60 days compared to placebo, but only the two lightest forms, at 50 and 130 kDa, reduced wrinkle depth, according to the 2022 review reporting this randomized trial.
In 40 women aged 25 to 55 with mild to moderate signs of aging, a range of five treatments combining five molecular weights of hyaluronic acid, from 1 to 2,000 kDa, and a cross-linked form reduced the volume of crow's feet wrinkles by 26.3% and their depth by 21.8% in 30 days, with no change under placebo. The products were stopped 8 to 12 hours before each measurement; however, the authors attribute part of the effect to hydration through occlusion from high molecular weight forms.
Nobile V, Buonocore D, Michelotti A, Marzatico F. J Cosmet Dermatol 2014;13(4):277-287. DOI: 10.1111/jocd.12120
In aging skin. In a double-blind trial of 36 residents in a nursing home with dry skin, a low molecular weight lotion applied to the leg for 4 weeks hydrated skin better than a high molecular weight lotion and than lotion without active ingredient, with no difference in insensible water loss. Without a control group, an open-label study funded by the manufacturer measured improved hydration at 4 and 8 weeks in 46 adults aged 27 to 69 years, without being able to separate the effect of the serum from that of the provided routine.
| Protocol | Measured result | Study |
|---|---|---|
| Serum with 1% sodium hyaluronate, 123 volunteers, one application | +17.8% hydration at 30 minutes, non-significant difference at 8 hours | Maldonado López, 2026 |
| Creams at 0.1%, 50 to 2,000 kDa, wrinkles around the eyes, 60 days | Hydration and elasticity improved with all, shallower wrinkles with 50 and 130 kDa | Trial reported by Bravo, 2022 |
| Range of five treatments, six forms, 40 women, 30 days | Crow's feet wrinkles: volume −26.3%, depth −21.8% | Nobile, 2014 |
| Low molecular weight lotion, 36 people aged 60 to 80, 4 weeks | 56.37 hydration units, versus 52.37 in high molecular weight and 49.01 without active ingredient | Muhammad, 2024 |
| High molecular weight serum and peptide, 46 adults, 8 weeks, without control | Increased hydration at 4 and 8 weeks | Robinson, 2022 |
In practice, evaluate a new serum over one to two months, without changing the rest of your routine.
Serum, cream, gel or mask: what are the differences?
According to a 2010 review, the vast majority of skincare products are fundamentally moisturizers, built on occlusives like petroleum jelly or dimethicone and humectants like glycerin. The delivery system determines the sensation and duration of the effect.
The serum is fluid, rich in water and humectants, sometimes oil-free, like the one in the 2026 trial: it hydrates quickly and layers easily. The cream is an emulsion of water and oils; according to a 2022 review, the occlusive and softening power increases from lotion to water-based cream, then to rich cream and balm. The gel, made from gelled water, is the lightest texture. The mask is applied for a few minutes.
In a randomized trial, sheet masks soaked in water, hyaluronic acid or bifidobacteria lysate were worn for 5 to 40 minutes: hydration rose then fell, and sebum increased with duration. Among 28 volunteers, 57.14% experienced dryness and 10.71% experienced redness, especially with pure water masks worn for more than 25 minutes; the authors consider wearing time of less than 25 minutes beneficial. Our article on collagen masks details what you can expect from this format.
| Format | Typical composition | For which skin types | Key points |
|---|---|---|---|
| Serum | Water and humectants, little to no oils | All skin types, as a first step | Alone, its hydrating effect did not last 8 hours in one trial |
| Cream | Emulsion: humectants, emollients, occlusives | Dry, mature, cold climate | Hydration still above baseline at 8 hours in the same trial |
| Gel | Gelled water, light texture | Oily, combination, acne-prone | Weakly occlusive: a light cream can complement it |
| Mask | Sheet or cream | All skin types, occasionally | Less than 25 minutes, then a cream |
Our Hyaluronic acid serum belongs to the first family: its formula starts with water and aloe vera leaf juice, with glycerin and sodium hyaluronate, and is used alone or before your regular cream.
Which format for your skin type
According to a review dedicated to moisturizers, the choice depends first on skin type, then on season and treatment area: oil-rich textures for dry skin, lotions and water-based creams for oily skin, lighter textures in summer and occlusive-rich creams in winter.
Dry skin. Serum then nourishing cream, morning and evening. Glycerin improves hydration of the stratum corneum and barrier function, with particular benefit when air is dry and cold, according to a review in the British Journal of Dermatology. On the nutrition side, our guide on borage and evening primrose oils covers this.
Oily or combination skin. In practice, a serum or gel often suffices on oily areas, with a light cream on dry areas. In the 2026 trial, conducted on dry or normal skin, surface sebum increased 8 hours after serum alone or cream alone, but remained close to baseline with the complete routine: to be confirmed on oily skin.
Acne-prone skin. An expert review recommends accompanying acne treatments, retinoids foremost, with cleansers, moisturizers, and photoprotection containing for example niacinamide or glycerin, to reduce irritation and facilitate treatment compliance. Dimethicone, a common occlusive in lightweight textures, is described as non-comedogenic. See also our article on supplements for acne.
Sensitive skin. Reactions to cosmetics, tingling, itching, burning, and more rarely contact allergy, are mainly linked to preservatives, fragrances, and additives. Cold and dry air further make skin more reactive to irritants.
Mature skin. It is the skin that has lost the most epidermal hyaluronic acid, and the one targeted by several trials, in adults up to 69 years old and residents aged 60 to 80. Our Hyaluronic Acid Serum was designed for mature, dehydrated, and wrinkled skin, to be applied before a richer cream.
Choosing well: form, associated ingredients, tolerance
The form. Over 95% of relevant cosmetics contain sodium hyaluronate, the salt of hyaluronic acid, rather than the acid itself, according to a 2021 review. Hydrolyzedhyaluronic acid corresponds to shortened chains, while crosslinked sodium hyaluronate (crosspolymer) corresponds to chains linked in a network, a way to compensate for a natural half-life of 12 to 24 hours in tissues. The list follows decreasing order of concentration, at least for main ingredients, so the position of the active indicates its place in the formula.
The concentration. The cited trials used 0.1% to 1%, and the same review places common cosmetic use between 0.2 and 1%. None of the trials selected here compare concentrations with each other.
Supporting humectants. Glycerin improves hydration and barrier function, and protects against certain irritants. Aloe vera has also been measured: in 20 women, a formula containing 0.25 or 0.5% lyophilized aloe extract, applied to the forearm, increased stratum corneum water from the first application, and all three concentrations tested, from 0.1%, after two weeks. Lipids (ceramides, cholesterol, free fatty acids) repair the barrier when supplied together, ideally in a 3:1:1 ratio according to a review; they are more commonly found in creams.
Our Hyaluronic Acid Serum combines sodium hyaluronate with aloe leaf juice and glycerin. The aloe trial was based on a lyophilized extract at precise concentrations: it informs about the ingredient, not our specific formula.
Tolerance. A 2021 review ranks hyaluronic acid among the most effective and safest cosmetic ingredients, and reminds that other actives in a formula, plant extracts or vitamins, can cause rare irritations or contact allergies.
Practical advice valid for any new product: if your skin reacts easily, apply it first to a small area, for example under the jaw, for a few days, before extending it to the face. In case of redness, itching, or swelling, stop it; if the reaction persists, a dermatologist can identify the culprit ingredient through patch testing.
How to apply a hyaluronic acid serum
Cleanse the face with a gentle cleanser and lukewarm water, rather than alkaline soap, then pat dry without rubbing: a review recommends applying moisturizers just after cleansing, skin dried, when occlusives best slow water loss. Apply a few drops of serum and spread them with light movements until fully absorbed, morning and evening, the frequency used in several trials.
From lightest to richest texture. Aqueous textures first, then richer textures, sunscreen last in the morning: this is practical advice, not a rule derived from a trial. However, the benefit of applying a cream over the serum has been well documented.
In 123 volunteers with dry or normal skin, a serum containing 1% sodium hyaluronate followed, approximately one minute later, by a cream with ceramides increased hydration by 20.0% at 30 minutes compared to simple cleansing. Eight hours later, only this routine remained significantly superior to the control, by 11.4%, while the serum alone and cream alone were no longer. The trial was funded by a skincare brand.
Maldonado López AM, da Silva Souza ID. Int J Cosmet Sci 2026;48(5):1042-1054. DOI: 10.1111/ics.70100
The authors explain this through the complementarity of mechanisms: the humectant attracts water, the cream retains it. Volunteers using the complete routine also judged their skin more hydrated immediately after application than those using only one of the two products.
Our Caviar cream does not contain hyaluronic acid and was not tested in this trial, whose cream combined ceramides, cholesterol, petrolatum and dimethicone: it complements the serum with its plant oils and glycerin, on thoroughly cleansed face and neck. One of these oils was studied alone: when applied to the forearm twice daily for 4 weeks, sunflower oil preserved the integrity of the stratum corneum and improved hydration, unlike olive oil, which impaired it. This result describes the oil alone, not our cream.
In cold or dry weather. Cold and low air humidity diminish the skin's barrier function, according to a 2016 review. The review dedicated to moisturizers recommends applying a humectant-based treatment approximately 30 minutes before exposure to cold, dry air, or choosing a product containing an occlusive if you go out immediately.
What to combine it with: vitamin C, niacinamide, retinol, sunscreen
None of the trials reviewed here test the precise combination of hyaluronic acid with any of the following actives: each has been studied independently.
Vitamin C. In a 6-month randomized double-blind trial, a 5% vitamin C cream applied to photodamaged skin on the décolletage and arms improved overall appearance score compared to its vehicle, thickened microrelief and reduced deep wrinkles, with good tolerance. Being unstable, water-soluble vitamin C penetrates poorly, making the formulation a key selection criterion. In practice, it is applied in the morning, before serum and sunscreen. For dietary sources, see our guide on natural vitamin C.
Niacinamide. In 50 women aged 40 to 60, a moisturizer with 5% niacinamide applied to half the face for 12 weeks reduced fine lines, spots, redness, sallow complexion and skin texture more than the same moisturizer without niacinamide, with good tolerance, in a trial conducted by a cosmetic company. On cultured keratinocytes, it multiplies ceramide synthesis by 4.1 to 5.5 times, and when applied to dry skin, it reduced transepidermal water loss. Our article on niacinamide details its effects.
Retinol. In 36 people with an average age of 87 years, a 0.4% retinol lotion applied to one arm up to 3 times weekly for 24 weeks reduced fine lines by 1.64 points on a scale of 0 to 9, compared to 0.08 with the vehicle, and increased glycosaminoglycans in a subgroup, the family of hyaluronic acid. The downside of retinoids is irritation, burning, peeling, dermatitis, especially with tretinoin and tazarotene, retinol being significantly less irritating; an expert review on acne recommends accompanying retinoids with moisturizers. In practice: a few evenings per week initially (the trial used no more than 3 applications per week), with the serum and cream.
The trial above involved a lotion applied to the skin. Retinol also exists as a dietary supplement, through another route: our Retinol (vitamin A) provides 1,000 µg of vitamin A per capsule, to be taken with meals; it is not recommended for pregnant or nursing women and requires medical advice after menopause or under treatment. Our article oral retinol or cream compares both routes.
Sunscreen. This is the best-supported combination, by a large-scale, long-duration randomized trial.
In 903 Australian adults under 55 years old, daily application of broad-spectrum sunscreen for 4.5 years showed no detectable progression of skin aging; this aging was 24% less than in the group that used sunscreen as convenient.
Hughes MC, Williams GM, Baker P, Green AC. Ann Intern Med 2013;158(11):781-790. DOI: 10.7326/0003-4819-158-11-201306040-00002
A 2010 review qualifies sunscreen as the most active anti-aging ingredient in skincare. In the morning, it is applied last, over the cream.
| Active Ingredient | What the trials show | Recommended timing | Precaution |
|---|---|---|---|
| Vitamin C | 5% for 6 months: improved microrelief and deep wrinkles | Morning, before serum | Unstable molecule: the formula matters |
| Niacinamide | 5% for 12 weeks: reduced fine lines, spots, and redness | Morning or evening | Well tolerated in the trial |
| Retinol | 0.4% for 24 weeks: reduced fine lines | Evening, a few times per week to start | Possible irritation; avoid during pregnancy |
| Sunscreen | 4.5 years: 24% less skin aging than with convenient use | Morning, last step | Daily use, as in the trial |
The typical routine, morning and evening
This routine is suitable for adult skin without skin conditions; if undergoing dermatological treatment, first follow your doctor's instructions.
Pregnancy, reactive skin: precautions
Pregnancy and breastfeeding. The trials on the serums and creams cited here excluded, when specified, pregnant or breastfeeding women: none therefore provides direct information on the use of a hyaluronic acid serum during this period. Topical retinoids prescribed for acne (adapalene, tretinoin, tazarotene) are contraindicated during pregnancy, according to a review of adverse effects of acne treatments; as a precaution, retinol in cosmetics should also be avoided without medical advice. Our article on retinol during pregnancy details these precautions. Before introducing a new skincare product, discuss it with your doctor or midwife.
Reactive skin. One new product at a time, tested first on a small area, as explained above.
Stop the product and consult in case of spreading redness, intense itching, swelling of the eyelids or lips, weeping patches or pimples appearing after a new product: a dermatologist can investigate contact allergy through patch testing. After a hyaluronic acid injection, follow the instructions of the doctor who performed it before resuming your skincare on that area. Persistent redness, inflammatory pimples or skin peeling despite hydration also warrant medical advice: this could be a treatable skin condition.
And orally?
In a randomized, double-blind trial, 40 Asian adults aged 35 to 64 took 120 mg of hyaluronic acid daily or placebo for 12 weeks: under hyaluronic acid, water content in the stratum corneum of the face was higher, transepidermal water loss was lower and elasticity was better, with more favorable wrinkle changes from 8 weeks on; three of the authors worked for the ingredient manufacturer. A 2023 review considers oral hyaluronic acid and hydrolyzed collagen well-tolerated and capable of attenuating certain signs of aging, based on trials that are often small, short, and particularly female-focused.
Our Marine Collagen and Hyaluronic Acid capsules provide, per 4 capsules, 1,208 mg of Naticol® marine collagen, 200 mg of hyaluronic acid, 160 mg of vitamin C and 3.96 mg of manganese; the powder version provides 10 g of Naticol® marine collagen, 210 mg of hyaluronic acid and 80 mg of vitamin C per day. The trial focused on 120 mg of hyaluronic acid alone: these combinations were not tested in it. Our comparison serum or capsules details the two pathways, and our guide on collagen and wrinkles covers collagen peptides.
A facial serum with sodium hyaluronate, combined with aloe vera leaf juice and glycerin, designed for mature, dehydrated and wrinkled skin. Apply a few drops morning and evening to clean, thoroughly cleansed skin, alone or before your regular cream.
View the Hyaluronic Acid SerumThen apply our Caviar Cream, with hydrolyzed marine collagen and caviar extract, for the face and neck.
Frequently Asked Questions
How to apply a hyaluronic acid serum?
On clean skin, just after cleansing, apply a few drops and spread with light movements until absorbed, morning and evening. Then apply a cream: in a trial of 123 volunteers, only the serum followed by cream routine maintained superior hydration compared to control at 8 hours after. In the morning, finish with sunscreen.
Hyaluronic acid: morning or evening?
Both: several trials applied it twice daily. In the morning, it goes before cream and sunscreen; in the evening, before cream, and hydration helps better tolerate a retinoid. Consistency and the cream applied on top matter more than the time of day.
Should you apply a cream after a hyaluronic acid serum?
Yes. In a trial of 123 volunteers, serum alone increased hydration by 17.8% at 30 minutes, but not significantly at 8 hours after; followed by a cream, it remained superior to control by 11.4% at 8 hours. A humectant draws water in, the cream retains it.
What is the best hyaluronic acid serum?
Trials each test a specific formula, often funded by its manufacturer, which does not allow us to designate a best serum. Aim for a formula with sodium hyaluronate combined with other humectants such as glycerin or aloe vera, a texture suited to your skin type, and good tolerance.
Serum or hyaluronic acid cream: which to choose?
Both complement each other: the serum hydrates quickly, the cream retains water over time. Dry and mature skin benefits from the duo morning and evening; oily skin can make do with a serum or gel, with a light cream on dry areas.
What is a hyaluronic acid mask worth?
It hydrates temporarily, provided you don't leave it on too long. In a randomized trial, hydration increased then decreased, and dryness and redness appeared especially with pure water masks worn longer than 25 minutes. Keep it on for less than 25 minutes, then apply a cream.
Is low molecular weight hyaluronic acid more effective?
It penetrates better: from 20 to 300 kDa, it crosses the stratum corneum in an ex vivo study, unlike forms of 1,000 to 1,400 kDa, and only forms of 50 and 130 kDa reduced wrinkle depth in a trial. Long-chain forms do form a film that limits evaporation, hence the benefit of formulas combining multiple sizes.
Can vitamin C and hyaluronic acid be combined?
Yes, their roles differ. A cream with 5% vitamin C applied for 6 months improved the microrelief of photoaged skin in a trial versus vehicle, hyaluronic acid acting mainly on hydration. In practice, in the morning: vitamin C, then hydrating serum, cream and sunscreen.
Niacinamide and hyaluronic acid: in what order?
From thinnest to richest texture, a practical tip rather than a rule from a trial. Niacinamide at 5% reduced fine lines, spots and redness in 12 weeks in 50 women, complementing the hydrating effect of hyaluronic acid.
Retinol and hyaluronic acid: how to combine them?
In the evening, apply retinol a few evenings per week initially, then the serum and cream to limit dryness. Retinol at 0.4% reduced fine lines in 24 weeks in a trial, but retinoids can irritate, and hydrating products help tolerate them. During pregnancy, topical retinoids should be avoided: those prescribed for acne are contraindicated.
How long does it take to see results from a hyaluronic acid serum?
Hydration is measurable at 30 minutes after application. Effects on texture and elasticity were measured after 30 to 60 days in trials, for example crow's feet wrinkles 21.8% less deep after 30 days with a range containing six forms of hyaluronic acid.
Does a hyaluronic acid serum replace an injection?
No. Applied to the skin, hyaluronic acid acts mainly on the surface, in the stratum corneum where it accumulates, whereas an injection provides a gel intended to restore tissue volume. No trial shows that a skincare product corrects a deep fold or volume loss: this decision is a matter for a physician.
Sources
The studies cited below were identified via PubMed.
- Maldonado López AM, da Silva Souza ID. A serum then moisturizer routine outperforms separate use in maintaining hydration, reducing transepidermal water loss, and balancing surface lipids over 8 hours. International Journal of Cosmetic Science, 2026;48(5):1042-1054. DOI
- Bravo B, Correia P, Gonçalves Junior JE, et al. Benefits of topical hyaluronic acid on skin quality and signs of skin aging: from literature review to clinical evidence. Dermatologic Therapy, 2022;35(12):e15903. DOI
- Juncan AM, Moisă DG, Santini A, et al. Advantages of hyaluronic acid and its combination with other bioactive ingredients in cosmeceuticals. Molecules, 2021;26(15):4429. DOI
- Essendoubi M, Gobinet C, Reynaud R, et al. Penetration into human skin of hyaluronic acid with different molecular weights, studied by Raman spectroscopy. Skin Research and Technology, 2016;22(1):55-62. DOI
- Nobile V, Buonocore D, Michelotti A, Marzatico F. Anti-aging and filling efficacy of a dermocosmetic treatment with six types of hyaluronic acid: a randomized double-blind clinical trial of efficacy and tolerance. Journal of Cosmetic Dermatology, 2014;13(4):277-287. DOI
- Ahn CS, Rao BK. Life cycles and biological pathways of elimination of dermal filler products. Journal of Cosmetic Dermatology, 2014;13(3):212-223. DOI
- Hughes MC, Williams GM, Baker P, Green AC. Sunscreen and prevention of skin aging: a randomized trial. Annals of Internal Medicine, 2013;158(11):781-790. DOI
- Robinson DM, Vega J, Palm MD, et al. Multicenter evaluation of a topical serum with hyaluronic acid. Journal of Cosmetic Dermatology, 2022;21(9):3848-3858. DOI
- Kang SY, Um JY, Chung BY, et al. Moisturizers in patients with inflammatory skin diseases. Medicina (Kaunas), 2022;58(7):888. DOI
- Grégoire S, Man PD, Maudet A, et al. Skin penetration of hyaluronic acid evaluated by tape stripping and ELISA assay. Journal of Pharmaceutical and Biomedical Analysis, 2023;224:115205. DOI
- Muhammad P, Novianto E, Setyorini M, et al. Efficacy of topical hyaluronic acid with different molecular weights in the treatment of skin xerosis in elderly subjects: a randomized, double-blind controlled trial. Archives of Dermatological Research, 2024;316(6):329. DOI
- Draelos ZD. Active ingredients in common skin care products. Plastic and Reconstructive Surgery, 2010;125(2):719-724. DOI
- Wang Y, Cao Y, Huang X, et al. Short-term skin reactions and stratum corneum modifications according to different modes of use of fabric masks. Journal of Tissue Viability, 2024;33(4):831-839. DOI
- Fluhr JW, Darlenski R, Surber C. Glycerol and skin: a comprehensive approach to its origin and functions. British Journal of Dermatology, 2008;159(1):23-34. DOI
- Kircik L, Tan J, Lain ET, et al. A comprehensive approach to acne management to improve skin quality and treatment outcomes, with or without sensitive skin. International Journal of Dermatology, 2025;64(4):637-646. DOI
- Engebretsen KA, Johansen JD, Kezic S, et al. Effect of ambient humidity and temperature on skin barrier function and dermatitis. Journal of the European Academy of Dermatology and Venereology, 2016;30(2):223-249. DOI
- Dal'Belo SE, Gaspar LR, Maia Campos PM. Moisturizing effect of cosmetic formulas containing aloe vera extract at different concentrations, evaluated by skin bioengineering techniques. Skin Research and Technology, 2006;12(4):241-246. DOI
- Danby SG, AlEnezi T, Sultan A, et al. Effect of olive and sunflower oils on adult skin barrier: implications for neonatal skin care. Pediatric Dermatology, 2013;30(1):42-50. DOI
- Humbert PG, Haftek M, Creidi P, et al. Topical ascorbic acid on photoaged skin: clinical, topographic and ultrastructural evaluation, double-blind placebo-controlled study. Experimental Dermatology, 2003;12(3):237-244. DOI
- Stamford NP. Stability, transdermal penetration and skin effects of ascorbic acid and its derivatives. Journal of Cosmetic Dermatology, 2012;11(4):310-317. DOI
- Bissett DL, Miyamoto K, Sun P, et al. Topical niacinamide reduces yellowing of skin tone, wrinkles, redness, and pigmented spots on aging facial skin. International Journal of Cosmetic Science, 2004;26(5):231-238. DOI
- Tanno O, Ota Y, Kitamura N, et al. Nicotinamide increases ceramide biosynthesis and other lipids in the stratum corneum to improve the epidermal barrier. British Journal of Dermatology, 2000;143(3):524-531. DOI
- Kafi R, Kwak HS, Schumacher WE, et al. Improvement of naturally aged skin by vitamin A (retinol). Archives of Dermatology, 2007;143(5):606-612. DOI
- Mukherjee S, Date A, Patravale V, et al. Retinoids in the treatment of skin aging: clinical efficacy and tolerability. Clinical Interventions in Aging, 2006;1(4):327-348. DOI
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