Skip to content

Resveratrol

Resveratrol suppliers and sourcing guide

Resveratrol is a stilbene, sold as the trans isomer, found in grape skins, peanuts and especially the root of Japanese knotweed (Reynoutria japonica, also called Polygonum cuspidatum). Most supply is extracted from knotweed root with water-alcohol solvents and purified to 50% or 98% trans-resveratrol; nature-identical material is also made by chemical synthesis and by yeast fermentation. Brands usually buy a 98% powder and specify the source.

Also known as
trans-Resveratrol · 3,4',5-Trihydroxystilbene · Japanese knotweed extract
Facts checked
November 2026

Forms and grades of resveratrol

Suppliers sell different products under the same name. Specify the one you need.

  • Knotweed extract, 98%

    Purified trans-resveratrol from Japanese knotweed root, the most common grade for capsules and powders.

  • Knotweed extract, 50%

    Lower-purity extract that carries other knotweed compounds, including emodin, so the specification should limit it.

  • Synthetic trans-resveratrol

    Made by chemical synthesis to high purity, with no plant co-extractives.

  • Fermentation-derived

    trans-Resveratrol produced by engineered yeast and purified, offered by a small number of suppliers.

  • Micronized and dispersible grades

    Reduced particle size or carrier-based powders for drinks and gummies, since resveratrol dissolves poorly in water.

What to check on the COA

Compare each result with your own specification when the lot arrives.

trans-Resveratrol assay (HPLC)
trans-Resveratrol content by HPLC, with cis-resveratrol reported separately because light converts trans to cis.
Emodin
For knotweed-sourced material, emodin and related anthraquinones by HPLC against the buyer's limit.
Identity
HPLC retention time and UV spectrum, plus HPTLC fingerprint for botanical extracts.
Residual solvents
Ethanol and any other process solvents against USP <467> or the buyer's limits.
Heavy metals and pesticides
Lead, arsenic, cadmium and mercury by ICP-MS, and a pesticide screen for plant-derived lots.
Microbiology
Total plate count, yeast and mold, and pathogens.

Storage, lots and expiry

Storage and shelf life

Keep resveratrol in sealed, opaque containers away from light, heat and moisture, since light exposure converts trans-resveratrol to the cis form. Use lined drums or foil bags and reseal promptly. Shelf life is set by the supplier's specification, with trans-resveratrol assay repeated at retest.

Lots and expiry dates

Record trans-resveratrol, cis-resveratrol and, for knotweed material, emodin for each lot. Keep the source (knotweed, synthetic or fermentation) on lot records, since it can change between suppliers or contracts.

Regulatory status

Facts from regulators and standards bodies, each linked to its source.

This is general information, not regulatory advice. Status differs by country and by how the ingredient is used, so check the rules for your product and market.

Resveratrol suppliers

Manufacturers and distributors whose own websites say they sell it.

We are checking resveratrol suppliers now

Every listing is checked against the supplier’s own website before it goes live, so this list fills in over the coming weeks. The specs and COA checklist above are ready today.

Sell resveratrol? Request a listing

Frequently asked questions

What forms of resveratrol can brands buy?

Common forms include knotweed extract, 98%, knotweed extract, 50%, synthetic trans-resveratrol, fermentation-derived and micronized and dispersible grades. Ask each supplier for the specification sheet of the exact grade they quote.

What should the COA for resveratrol include?

Expect trans-Resveratrol assay (HPLC), emodin, identity, residual solvents, heavy metals and pesticides and microbiology, each with its method, specification and result for that lot.

How should resveratrol be stored?

Keep resveratrol in sealed, opaque containers away from light, heat and moisture, since light exposure converts trans-resveratrol to the cis form. Use lined drums or foil bags and reseal promptly. Shelf life is set by the supplier's specification, with trans-resveratrol assay repeated at retest.

What is the regulatory status of resveratrol?

A Health Canada natural health product monograph lists resveratrol from Reynoutria japonica root, Vitis vinifera fruit, biosynthesis by Saccharomyces cerevisiae, and synthetic preparation. GRN 224, for trans-resveratrol in bottled water from ATLA Holdings, ended in 2007 with FDA ceasing to evaluate the notice at the notifier's request.

Sell ingredients to brands?

Request a free listing for the ingredients you make or distribute. No paid placement.

Request a listing