Three Disqualifying Red Flags

  1. Cannot or will not report quercetin, kaempferol and isorhamnetin individually. Their HPLC method produces these three numbers — the 24% figure is calculated from them. Refusing to report them is not a cost issue. Decline.
  2. Reports terpene lactones as "complies" rather than a figure, or does not test them separately from the flavone fraction. The 6% half is the half that cannot be faked; a supplier not measuring it properly has skipped the useful test.
  3. Does not test ginkgolic acids. Removing them below 5 ppm requires a deliberate purification step. A supplier not measuring almost certainly does not have one — which is both a safety failure and a reliable signal about the rest of their process.

The one-question filter: "Will you report quercetin, kaempferol and isorhamnetin individually, with the ratio confirmed against the authentic range, on every batch CoA?" Ask it before discussing price. On ginkgo this single question sorts the field more reliably than any audit, because the answer reveals both analytical capability and willingness to be held to it.

The Scoring Framework

Weighted to 100 points, with authenticity carrying 40 — far above where a generic botanical checklist would put it. That imbalance is intentional and reflects where the actual risk sits on this ingredient.

1. Authenticity Capability — 40 points

CriterionPoints
Quercetin, kaempferol, isorhamnetin reported individually with ratio confirmed12
Rutin screened and reported "not detected"8
Terpene lactones NLT 6% verified as a figure, every batch8
Ginkgolides A, B, C and bilobalide reported individually6
HPLC fingerprint against authentic reference available4
TLC identity against reference material2

2. Ginkgolic Acid Control — 15 points

CriterionPoints
Ginkgolic acids by HPLC, reported as a figure against NMT 5 ppm8
Can supply to a tighter ceiling (NMT 1 ppm) on request4
Can describe the removal step in their process3

That last row is worth asking about directly. A manufacturer who can explain how they remove ginkgolic acids is a manufacturer. One who cannot is probably buying extract and relabelling it — which means their authenticity controls are someone else's, and you cannot audit them.

3. Documentation and Reporting Discipline — 15 points

CriterionPoints
Full profile appears on every batch CoA, not qualification only6
Batch-specific CoA, not a generic specification sheet4
Assay stated on dry basis; carriers declared by name and percentage3
Residual solvent including acetone reported2

The first row addresses a real and specific pattern: suppliers qualifying with a beautiful full-profile certificate, then shipping routine batches carrying only "24/6 complies". Write the ongoing reporting requirement into the specification, and score suppliers on whether they accept it without argument.

4. Compliance and Contaminant Testing — 15 points

CriterionPoints
Heavy metals by ICP-MS with numeric per-element limits5
Full USP microbiological panel including pathogens4
EU pesticide MRL screening with a real report3
Non-ETO declaration with LC-MS/MS available3

5. Consistency and Commercial Terms — 15 points

CriterionPoints
Three consecutive batch CoAs with consistent aglycone ratios6
Batch traceable to raw-material lot3
Incoterms quoted properly to your named destination2
Written payment terms on a proforma invoice2
Technical questions answered by someone who understands the chemistry2

The three-batch aglycone comparison is the most revealing request on this checklist. Authentic ginkgo from a stable supply chain shows a consistent ratio batch to batch. Ratios that wander suggest the supplier is blending from varying sources — and on this ingredient, "varying sources" is precisely the risk.

Interpreting the Score

ScoreReading
85–100Qualified for bulk supply. Proceed to sample and pre-shipment verification.
70–84Workable with conditions. Close the gaps in writing before first bulk order.
55–69Trial quantities only, with independent authenticity verification on every lot.
Below 55Not a ginkgo supplier for a regulated market.

Apply a hard floor on section 1: below 25 of 40, decline regardless of total. A supplier can score full marks on compliance, terms and responsiveness while being entirely unable to demonstrate that what they sell is ginkgo. On this ingredient, more than any other in the category, the aggregate score must not be allowed to obscure that gap.

The Sample Stage

First-Order Protocol

  1. Nominate an independent laboratory — Eurofins, SGS or Intertek. Specify the aglycone ratio and rutin screen in the scope, not just 24/6 assay. This is the single most important instruction in this article: an independent 24/6 result alone reproduces the exact blind spot that makes ginkgo adulteration possible, and buyers pay for it routinely without realising.
  2. Compare the independent aglycone ratio against the supplier's. Agreement on the total but divergence on the ratio is the signature you are testing for.
  3. Confirm the terpene lactone figure independently — the half that cannot be faked.
  4. Retain a sealed, dated sample for the shelf life of the material.
  5. Re-verify at batch three, then at least annually, and always on a change of manufacturing site or a notable price movement.

SV Botanica supplies bulk ginkgo extract from certified facilities in India with the quercetin:kaempferol:isorhamnetin ratio, rutin screen, individual ginkgolides and bilobalide, and ginkgolic acid figure on every batch certificate. Buyer-nominated third-party pre-shipment testing is welcome and encouraged. See the product page, the buyer's guide, or adulteration and authenticity.