Resveratrol is a naturally occurring stilbene polyphenol. The biologically and cosmetically relevant form is generally trans-resveratrol, also known as trans-3,5,4'-trihydroxystilbene.

Resveratrol is produced by plants as a phytoalexin, meaning that its production can increase in response to environmental stress and attack by microorganisms such as fungi and bacteria.

INCI Name: Resveratrol
Chemical Name: trans-3,5,4'-Trihydroxystilbene
CAS Number: 501-36-0
Molecular Formula: C14H12O3
Molecular Weight: 228.24 g/mol
Chemical Class: Stilbene Polyphenol
Function: Antioxidant, Skin Protectant

Natural Sources

Resveratrol occurs naturally in a number of plants. It is particularly associated with the skins of red grapes and products derived from grapes, including red wine.

It is also found in Japanese knotweed (Fallopia japonica), which is one of the important commercial botanical sources of resveratrol. The compound has also been identified in other plant species.

In plants, resveratrol is synthesized as part of a defense response to environmental stress and microbial attack. Fungal infection, particularly by Botrytis species, can stimulate its production.

History

Resveratrol was originally isolated from the roots of white hellebore by the Japanese researcher Michio Takaoka in 1940. It was subsequently identified in the roots of Japanese knotweed in 1963.

Interest in resveratrol increased substantially following research into the so-called "French Paradox", the epidemiological observation that some populations consuming diets containing relatively high levels of saturated fat appeared to have lower rates of cardiovascular disease while also consuming red wine.

Although resveratrol has demonstrated antioxidant and biological activity, the amount of resveratrol present in red wine is generally considered too low to conclusively explain the entire phenomenon. The relationship between dietary resveratrol, red wine consumption and cardiovascular health remains more complex than the original hypothesis suggested.

Antioxidant Properties

Resveratrol is a potent polyphenolic antioxidant that can interact with reactive oxygen species and influence several cellular pathways associated with oxidative stress.

Oxidative stress is an important contributor to skin aging and can be increased by environmental factors such as ultraviolet radiation and pollution. Because of this, resveratrol has attracted significant interest as a cosmetic active for products designed to support the skin's defense against oxidative damage.

Its antioxidant activity has also been investigated in comparison with other cosmetic antioxidants. Some supplier-sponsored studies have reported very high antioxidant activity for specific resveratrol-based formulations compared with other antioxidant systems. Such comparisons should be interpreted in relation to the test method and formulation rather than treated as a universal ranking of antioxidant efficacy.

Anti-Aging and Photoaging

Resveratrol has been extensively investigated as a potential anti-aging cosmetic active.

Research suggests that resveratrol can influence several pathways involved in cellular aging, oxidative stress, inflammation and extracellular matrix degradation. It has also been studied in relation to the prevention of photoaging caused by chronic exposure to ultraviolet radiation.

One area of particular interest is the relationship between resveratrol and Sirtuin 1 (SIRT1), a protein involved in cellular stress responses, metabolism and longevity-associated signaling. Resveratrol has been reported to activate or influence SIRT1-dependent pathways under certain experimental conditions.

However, the biological mechanisms of resveratrol are complex and the extent to which SIRT1 activation contributes to topical cosmetic effects in humans remains an area of continuing research.

Skin Protection

Resveratrol may help protect skin cells against oxidative stress generated by environmental factors, including UV exposure.

Laboratory and experimental studies have investigated its effects on oxidative stress, inflammatory signaling and cellular responses to UV radiation. These findings provide a scientific rationale for including resveratrol in products designed to support skin protection and anti-aging routines.

Resveratrol should not, however, be considered a replacement for sunscreen. A cosmetic product containing resveratrol does not automatically provide a validated level of UV protection unless the finished product has been appropriately tested and complies with the applicable sunscreen regulations.

Collagen and Skin Structure

Resveratrol has been investigated for its potential effects on processes associated with collagen degradation and extracellular matrix remodeling.

UV exposure can increase oxidative stress and stimulate enzymes involved in the breakdown of collagen and other extracellular matrix components. Experimental research suggests that resveratrol may influence some of these pathways.

These findings have contributed to interest in resveratrol as an ingredient for products targeting the visible signs of skin aging, although the magnitude of the effect in topical cosmetic use depends on the formulation, concentration, delivery system and skin exposure.

Formulation Considerations

Resveratrol presents formulation challenges because it has low water solubility. Appropriate formulation strategies may therefore be required to achieve adequate dispersion, solubilization and delivery.

Resveratrol can be incorporated into oil-containing systems or formulated using suitable solubilizers, emulsions, encapsulation systems or other delivery technologies depending on the intended product.

Because the compound is sensitive to environmental conditions and its stability can depend on the formulation matrix, the choice of solvent system, pH, packaging and antioxidant system should be considered during product development.

Stability

Resveratrol is sensitive to factors including light, oxygen and environmental conditions. The trans form can undergo isomerization under certain conditions, potentially affecting the chemical profile and performance of the formulation.

Appropriate protection from light and oxygen can therefore be beneficial. Packaging selection should take into account the sensitivity of the active ingredient as well as the composition of the finished product.

Finished formulations should undergo appropriate stability testing to monitor changes in appearance, color, odor, pH, viscosity and active ingredient content throughout the intended shelf life.

Skin Compatibility

Resveratrol is generally considered suitable for topical cosmetic applications and has been investigated in a range of skincare formulations.

Available research suggests that topical resveratrol is generally well tolerated, although individual sensitivity or irritation can occur with any active cosmetic ingredient. The overall tolerability of a product depends on the concentration, formulation vehicle, delivery system and combination with other active ingredients.

Safety

A small human study reported that single oral doses of trans-resveratrol of up to 5 g produced no serious adverse effects in healthy volunteers, although gastrointestinal symptoms and other mild effects have been reported in studies using higher oral doses.

These oral safety data should not be directly extrapolated to topical cosmetic use. Topical exposure produces a substantially different pharmacokinetic profile, and the safety of a finished cosmetic product must be evaluated according to its concentration, application area, frequency of use and intended population.

Available evidence does not suggest that serious adverse effects should generally be expected from appropriately formulated topical resveratrol, although the safety assessment of the finished cosmetic product remains essential.

Toxicological Information

Historical toxicological sources have reported an estimated acute oral LD50 of approximately 2,000 mg/kg body weight for resveratrol.

This value should be treated as toxicological background information rather than as a direct measure of the safety of topical cosmetic use. LD50 values obtained from animal studies cannot be directly converted into a safe cosmetic concentration for human topical application.

A reliable ingredient-specific NOAEL should only be reported when the underlying toxicological study clearly identifies the test material, exposure route and relevant endpoint. Where such data are not sufficiently established for the intended cosmetic application, a NOAEL should not be inferred from the LD50 value.

Bioavailability

Resveratrol has relatively low systemic bioavailability following oral administration because of rapid metabolism and elimination.

Studies have demonstrated that resveratrol can be detected in plasma following oral exposure, although the majority of circulating material may occur as metabolites rather than unchanged resveratrol.

These pharmacokinetic characteristics have contributed to significant research into alternative delivery systems, including topical formulations and encapsulation technologies designed to improve local availability.

Cosmetic Applications

Resveratrol is used primarily in skincare products positioned around antioxidant protection and the visible signs of skin aging.

It may be incorporated into serums, creams, lotions, masks and other leave-on formulations. It is particularly suitable for formulations targeting mature skin, environmental stress and uneven or dull-looking skin.

Resveratrol is also frequently combined with other antioxidants and skin-conditioning ingredients to create multifunctional anti-aging formulations.

Regulatory Considerations

Resveratrol is a naturally occurring cosmetic ingredient and is used in cosmetic formulations in a number of markets. However, the regulatory status of a specific product depends on the ingredient specification, concentration, intended use and claims.

Cosmetic claims relating to antioxidant activity, skin conditioning or the appearance of signs of aging should be supported by appropriate evidence. Claims suggesting treatment or prevention of a disease or medical condition may cause a product to fall under medicinal regulations depending on the jurisdiction.

References

Dweck, Anthony. Handbook of Natural Ingredients. Dweck Books.

Baur, J. A. and Sinclair, D. A. “Therapeutic potential of resveratrol: the in vivo evidence.” Nature Reviews Drug Discovery, 2006, 5, 493–506.

Berman, A. Y., Motechin, R. A., Wiesenfeld, M. Y. B. and Holz, M. K. “The therapeutic potential of resveratrol: a review of clinical trials.” NPJ Precision Oncology, 2017, 1, 35.

Ratz-Łyko, A. and Arct, J. “Resveratrol as an active ingredient for cosmetic formulations.” Journal of Cosmetic and Laser Therapy.

National Center for Biotechnology Information. PubChem – Resveratrol.

National Center for Biotechnology Information. PubMed – Resveratrol and skin health.

European Commission. CosIng – Cosmetic Ingredients Database.

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