Mechanism of Action
Hyaluronic acid is naturally present in the skin’s extracellular matrix, the network that gives tissues their structure. It contributes to water retention and the skin’s mechanical properties.
After oral intake, preclinical work indicates that the gut microbiota breaks part of the molecule down into small oligosaccharides and metabolites. In humans, controlled trials directly document the skin outcome: improved hydration and favorable barrier measures. The intermediate steps remain to be clarified.
Key Benefits
- Strong
Noticeably better-hydrated skin: two independent meta-analyses of randomised controlled trials measure a significant rise in skin hydration after 4 to 12 weeks of daily intake, assessed by corneometry (the water content of the skin’s surface layers).
- Moderate
Shallower wrinkles and more supple skin: a meta-analysis of 7 controlled trials reports a measurable reduction in wrinkle depth and improved elasticity in adults supplemented for 4 to 12 weeks.
- Moderate
A skin barrier that holds water better: two randomised placebo-controlled trials, in 40 and then 150 adults, measure a fall in transepidermal water loss after 12 weeks at 120 mg per day.
- Emerging
Increased skin thickness: three randomised placebo-controlled trials, in 88 to 150 adults, measure this gain after 8 to 12 weeks of daily intake.
Dosage & Forms
Molecular weight distinguishes the forms of orally administered hyaluronic acid. Some preparations rely on a single fraction. Others combine several: the molecule is produced and renewed in the body across a range of sizes.
Skin trials range from 60 to 200 mg per day, over four to twelve weeks. Two meta-analyses cover that window. One trial in 150 adults compared 60 and 120 mg per day over twelve weeks: both doses moved the skin measurements, the lower one more modestly.
Two controlled trials evaluated 200 mg per day of ExceptionHYAL® Star, for 28 and 56 days respectively. It is the complete composition, several fractions combined, that was evaluated at this dose.
In the Singular Formula
Inclusion rationale
Hyaluronic acid is naturally present in the skin’s extracellular matrix, where it contributes to water retention and the mechanical properties of tissues. Two controlled human trials evaluated ExceptionHYAL® Star at 200 mg per day for 28 or 56 days. They report instrumental improvements in hydration and several skin parameters. This direct human evidence places hydration at the heart of its selection for the Singular formula.
Selected form
ExceptionHYAL® Star is a patented sodium hyaluronate from Roelmi HPC, produced by bacterial fermentation without animal-derived raw materials. It combines several molecular weights.
Formula dosage
0 to 200 mg.
Dose expressed as active substance, excluding excipients and carriers of the raw material.
Safety & Precautions
ExceptionHYAL® Star was well tolerated at 200 mg per day in the 28- and 56-day trials, with no adverse events reported. An authority assessment published in 2023 gathers seventeen randomised trials and about a thousand participants, from 25 to 225 mg per day, with no harmful effect recorded. The longest human follow-up reaches twelve months, at 200 mg per day. A few digestive discomforts were reported.
As a precaution, use remains discouraged during pregnancy and breastfeeding because specific data are unavailable.
Scientific Studies
| Authors | Year | Type | Journal | |
|---|---|---|---|---|
| Amin P et al. | 2025 | Meta-analysis | Journal of Drugs in Dermatology | View on PubMed |
Oral Hyaluronic Acid Supplement: Efficacy in Skin Hydration, Elasticity, and Wrinkle Depth Reduction Meta-analysis of 7 randomised controlled trials. Skin hydration, elasticity and wrinkle depth improve significantly on oral hyaluronic acid. Firmness, wrinkle volume and transepidermal water loss do not separate from placebo. The authors note a limited sample size and marked heterogeneity between the included trials. | ||||
| Dolečková I et al. | 2025 | Randomised Controlled Trial | Scientific Reports | View on PubMed |
Oral sodium hyaluronate improves skin hydration, barrier function and signs of aging: a randomized, double-blind, placebo-controlled trial in 150 healthy adults The largest published trial of oral sodium hyaluronate: 150 healthy adults, 60 or 120 mg per day for twelve weeks, versus placebo. At 120 mg, hydration and elasticity improve while transepidermal water loss and periorbital wrinkle depth fall. Epidermal thickness, dermal density and natural moisturising factors rise. At 60 mg the same effects appear, more modest. | ||||
| Sun Q et al. | 2022 | Meta-analysis | Frontiers in Nutrition | View on PubMed |
Effectiveness of Dietary Supplement for Skin Moisturizing in Healthy Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials Systematic review of 66 randomised trials of dietary supplements and skin hydration. Hyaluronan is among the substances whose effect on hydration comes out statistically significant. The effect on transepidermal water loss remains undetermined, for lack of enough trials. | ||||
| Michelotti A et al. | 2021 | Randomised Controlled Trial | European Journal of Dermatology | View on PubMed |
Oral intake of a new full-spectrum hyaluronan improves skin profilometry and ageing: a randomized, double-blind, placebo-controlled clinical trial Randomised, double-blind, placebo-controlled trial in 60 women with mild to moderate signs of skin aging. Twenty-eight days at 200 mg per day of full-spectrum hyaluronic acid: hydration up 10.6%, wrinkle depth down 18.8%, wrinkle volume down 17.6%, elasticity and firmness up 5.1%. No adverse events reported. | ||||
| Nobile V et al. | 2025 | Randomised Controlled Trial | Cosmetics | View on PubMed |
Oral Intake and Topical Application of Hyaluronic Acid Ameliorates Skin Aging Signs: Efficacy Results of a Placebo-Controlled In&Out Trial Randomised trial run in Italy and China in 88 adults aged 35 to 65, split into four groups including a double placebo, over 56 days. The group receiving 200 mg per day of ExceptionHYAL® Star with no active applied to the skin separates from the double placebo on smoothness, roughness, firmness, elasticity and hydration. Dermis thickness rises by 8.5% at 56 days, in a subpopulation of six subjects per group. No adverse events reported. | ||||
| Gao YR et al. | 2023 | Randomised Controlled Trial | Skin Research and Technology | View on PubMed |
Oral administration of hyaluronic acid to improve skin conditions via a randomized double-blind clinical test Double-blind randomised trial in 129 women. Oral hyaluronic acid (100 to 200 mg per day) improved skin hydration from week 2, skin tone from week 4, and epidermal thickness after 12 weeks, in both young and older participants. | ||||
| Hsu TF et al. | 2021 | Randomised Controlled Trial | Nutrients | View on PubMed |
Oral Hyaluronan Relieves Wrinkles and Improves Dry Skin: A 12-Week Double-Blinded, Placebo-Controlled Study Double-blind randomised trial in 40 adults aged 35 to 64. Twelve weeks at 120 mg per day improved wrinkles, stratum corneum water content, transepidermal water loss and skin elasticity versus placebo. | ||||
| Yang Q et al. | 2025 | Meta-analysis | Frontiers in Medicine | View on PubMed |
Effectiveness of dietary supplements for skin photoaging in healthy adults: a systematic review and meta-analysis of randomized controlled trials Systematic review and meta-analysis of 40 randomised trials of dietary supplements and skin photoaging. Collagen, flavanols and other polyphenols improve minimal erythema dose or overall elasticity. Hyaluronic acid, lycopene and carotenoids do not separate from placebo: this is the broadest published contradiction to date on the elasticity endpoint. | ||||