Tea polyphenols powder is sold under a grade number, and that number does not fix what the powder delivers. Two lots both labelled 98% can differ by 28 points of EGCG. The ladder only helps a buyer who recomputes it from the certificate.
1. Total Polyphenols Sets A Ceiling, Not A Dose
Total polyphenols is the assay that names the grade, and it says nothing about how much of that total is EGCG, because UV read against a gallic acid standard counts aromatic rings, not named molecules. A 98% figure means 98 grams of polyphenol in every 100 grams of powder. The catechin profile on the same certificate says how those grams divide.
Treating the grade number as a dose is the most common specification error on the buying side. A 500 mg capsule of a 95% grade carries at most 475 mg of tea polyphenols and, depending on the catechin profile, between 300 and 350 mg of EGCG. The gap between ceiling and content is where quotations separate.
2. The Grade Ladder Does Not Reconcile With One Catechin Profile
The four grades are usually published as a ladder where higher tea polyphenols brings higher EGCG, and that ladder does not close arithmetically. Divide the EGCG figure by the polyphenol figure to get EGCG as a share of total polyphenols, then compare that share with the catechin distribution the supplier publishes.
| Grade | Total polyphenols | EGCG in the powder | EGCG share of polyphenols | Fits one profile |
| 80% | ≥80% | 40% to 50% | 50.0% to 62.5% | Yes |
| 90% | ≥90% | 50% to 60% | 55.6% to 66.7% | Upper bound only |
| 95% | ≥95% | 60% to 70% | 63.2% to 73.7% | No |
| 98% | ≥98% | 70% to 98% | 71.4% to 100% | No |
One published profile puts EGCG at 50% to 60% of total catechins. A crude extract carries catechins at roughly 60% to 80% of total polyphenols, a ratio stated on this site's own green tea extract sheet. Multiply the two and tea polyphenols cannot carry more than about 48% EGCG, which at a 98% total is about 47% of the powder. The 98% grade claims 70% to 98%.
Only the 80% grade survives that test, and narrowly. At the top of the ladder, the product described is not a tea polyphenols extract with EGCG in it. It is EGCG with a little else in the beaker.
› Ask for EGCG and total polyphenols on one certificate, same lot
› Reject any grade whose EGCG exceeds 60% of its polyphenol figure
› Treat a 70% to 98% EGCG range as two products, not one grade
3. Caffeine Has To Be Costed Per Serving, Not Per Percentage
Caffeine is a co-extracted impurity in tea polyphenols rather than an added ingredient, and a percentage has to become milligrams before it means anything. A grade described as 1% or less still delivers measurable caffeine at a 500 mg serving.
| Grade | Caffeine in the powder | Per 300 mg serving | Per 500 mg serving |
| 80% | 5% to 8% | 15 to 24 mg | 25 to 40 mg |
| 90% | 3% to 5% | 9 to 15 mg | 15 to 25 mg |
| 95% | 1% to 3% | 3 to 9 mg | 5 to 15 mg |
| 98% | 1% or less | Up to 3 mg | Up to 5 mg |
The conversion is one multiplication: serving weight in milligrams times the caffeine percentage, compared with the per-serving limit your market sets. On the 80% grade a 500 mg serving carries 25 to 40 mg, where a sleep-positioned product stops being credible.
› Set the caffeine limit in milligrams per serving, then work back to a grade
› Treat 1% or less as low caffeine, not as decaffeinated
› Ask whether a decaffeinated grade is a separate run or a blend
Nothing in a tea polyphenols specification forces the word decaffeinated to mean a particular number, so a supplier can apply it to any lot below its own internal threshold. Buying on the word is how a low-caffeine grade reaches a market labelled caffeine free.
4. Three Daily EGCG Figures Answer Three Different Questions
Three figures circulate as a daily EGCG limit for tea polyphenols, and they are not competing versions of one number. Each came from a different dosing form, and the gap between the first two is the gap between a capsule and a drink.
| Figure | Where it comes from | What it governs |
| 338 mg EGCG per day | Derived safe intake, solid bolus | Capsules and tablets |
| 704 mg EGCG per day | Observed safe level, beverage form | Ready-to-drink and powder mixes |
| 800 mg EGCG per day | EFSA transaminase threshold | The level not to design toward |
| 90 to 300 mg per day | Mean intake from infusions | What a brewed cup delivers |
The 338 mg figure is a derived safe intake for adults, calculated for preparations taken as a solid bolus, which is what a capsule is. The 704 mg figure is an observed safe level for beverage form. Both come from one systematic review in Regulatory Toxicology and Pharmacology covering 159 human intervention studies, which states that dose form drives the difference.
EFSA arrived at 800 mg from another direction. Its 2018 opinion found that supplements supplying 800 mg EGCG a day or more produced a statistically significant rise in serum transaminases against control. That opinion sits under Article 8(2) of Regulation (EC) No 1925/2006, the route by which a substance is restricted in food.
The consequence is a design rule, not a label rule. A capsule brief works to roughly 338 mg of EGCG a day, a beverage brief to 704 mg, and both sit under the 800 mg line. Designing a capsule to the beverage figure doubles the safe exposure.
5. The CAS Number Proves Identity, Not Potency
Tea polyphenols carries CAS 84650-60-2, and that number names a class of extract rather than a molecule. It confirms that a shipment is green tea extract. It does not tell you the EGCG content, and treating it as a potency check is how a specification passes while the product fails.
PubChem resolves that CAS to CID 1287, titled Tea, ext., with formula C22H18O11 and a molecular weight of 458.4. EGCG resolves separately to CID 65064 with an identical formula and weight, because the extract record carries EGCG as its representative structure. A record sharing its formula with one of its components cannot quantify that component.
For a standardized extract the identity chain runs botanical source, plant part, extraction solvent and assayed marker, so a tea polyphenols lot means Camellia sinensis leaf, the solvent, and the marker the assay targets. A sheet listing a CAS and a formula closes the first link only.
› Ask for the plant part and the extraction solvent, not only the species
› Ask which marker the assay is standardized to, and by which method
6. Six Lines On The Certificate Of Analysis Decide The Order
A certificate for tea polyphenols is worth reading line by line, because six entries change what the material can be used for. The rest are hygiene.
| Line on the CoA | Method | What it settles |
| Total polyphenols | UV, as gallic acid | Whether the grade claim holds |
| EGCG | HPLC, against a pure standard | The marker the buyer pays for |
| Caffeine | HPLC | Fit for a sleep or children's brief |
| Moisture | Loss on drying | Whether the powder will cake |
| Heavy metals | ICP-MS | Lead and arsenic against your limit |
| Total plate count | USP | Whether the lot suits a capsule line |
Two lines decide the commercial argument. Total polyphenols confirms the grade you were quoted, and EGCG confirms what it is worth to your formula. The other four are pass or fail against your market's limit, where moisture causes caking on a capsule line and heavy metals stop a lot at a border. Grade options across the standardized extract range are quoted per specification.
7. Match The Grade To The Matrix Before You Compare Price
Every grade is right for one matrix and wrong for another, and price only compares inside a matrix. Choose the matrix, then the grade, then the price per kilogram of EGCG rather than of tea polyphenols.
| Matrix | Grade to specify | The binding constraint |
| Two-piece capsule | 95% or 98% | Fill weight times EGCG share |
| Ready-to-drink tea | 80% or 90% | Caffeine per serving, clarity |
| Powdered drink mix | 90% or 95% | Astringency at reconstitution |
| Leave-on cosmetic | 95% or 98% | Colour and odour in a white cream |
| Functional food | 80% | Cost per unit of polyphenol |
That conversion settles most negotiations. Divide price per kilogram by the EGCG percentage to get cost per kilogram of EGCG, and a 98% grade must cost under 1.2 times an 80% grade to win on marker content. It rarely does, which is why 80% stays in functional food and 95% in capsules.
Frequently Asked Questions
Q: Does Tea Polyphenols Powder Contain Caffeine?
A: Yes, unless the grade says otherwise. Caffeine is co-extracted with the catechins, so tea polyphenols are never caffeine free by default. Standard grades carry 1% to 8% caffeine and the lowest figure available is 1% or less. Convert that to milligrams per serving before deciding.
Q: Can A 98% Grade Really Carry 98% EGCG?
A: Not alongside a 98% total polyphenol figure, because EGCG is one polyphenol among several and the rest need the remaining space. A powder that is 98% EGCG is an EGCG isolate, and calling it tea polyphenols describes the source, not the content.
Q: Which Daily EGCG Limit Applies To A Capsule?
A: The solid bolus figure of 338 mg EGCG a day, because a capsule is a bolus dose taken on a comparatively empty stomach. The 704 mg figure applies to beverage form. Both sit below the 800 mg level at which EFSA found raised serum transaminases in supplement trials.
Q: Does The CAS Number Tell Me The EGCG Content?
A: No. CAS 84650-60-2 identifies green tea extract as a class, and PubChem resolves it to a record whose formula is the EGCG formula, so the number cannot separate one grade from another. EGCG content comes from an HPLC assay on the batch certificate, not from the identifier printed on a specification sheet.
Q: Why Do Two Suppliers Quote Different EGCG For The Same Grade?
A: Because the grade names a polyphenol total, not a catechin ratio. Two extracts at 95% total polyphenols can carry different EGCG shares depending on leaf source, harvest season and purification route. That is why EGCG has to be quoted and tested as a separate line.
Q: Is A Decaffeinated Grade The Same As The Lowest-Caffeine Grade?
A: Not necessarily, and the specification rarely settles it. The lowest standard grade is 1% caffeine or less, which is a measured figure. Decaffeinated is a process claim, and without a stated threshold it can describe any lot below a supplier's internal limit. Ask for the caffeine result in milligrams per serving instead.
Q: Which Grade Should I Specify For A Beverage?
A: The 80% or 90% grade, because a beverage tolerates more powder per serving and the caffeine ceiling is set by the drink rather than the capsule. The 80% grade is also the only rung whose EGCG share reconciles with a normal catechin profile, so it is the safest to specify.
Xi'an Huilin Bio-tech Co., Ltd. supplies tea polyphenols powder from Camellia sinensis leaf in 80%, 90%, 95% and 98% grades, with total polyphenols, EGCG and caffeine assayed on every lot.
Sources
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1. EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS). Scientific opinion on the safety of green tea catechins. EFSA Journal 2018;16(4):5239. https://efsa.onlinelibrary.wiley.com/doi/10.2903/j.efsa.2018.5239
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2. The safety of green tea and green tea extract consumption in adults: results of a systematic review. Regulatory Toxicology and Pharmacology, 2018. https://pubmed.ncbi.nlm.nih.gov/29580974/
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3. Regulation (EC) No 1925/2006 of the European Parliament and of the Council on the addition of vitamins and minerals and of certain other substances to foods. OJ L 404, 30.12.2006, p. 26. https://eur-lex.europa.eu/eli/reg/2006/1925/oj
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4. PubChem CID 1287, Tea, ext., CAS 84650-60-2, formula C22H18O11, molecular weight 458.4. https://pubchem.ncbi.nlm.nih.gov/compound/1287
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5. PubChem CID 65064, epigallocatechin gallate, formula C22H18O11, molecular weight 458.4. https://pubchem.ncbi.nlm.nih.gov/compound/65064
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6. Huilin Bio-tech, Tea Polyphenols Powder product page, grade table and certificate lines, accessed 28 October 2026.