Total Potential THC (TPTHC) is the cannabinoid figure that governs import classification, pharmacy dispensing, and procurement decisions across every medical cannabis market your LP serves. Most COAs lead with THCA, not TPTHC, and that gap trips up B2B buyers more than almost any other documentation issue.
Two figures appear on every cannabis COA: THCA (tetrahydrocannabinolic acid) and delta-9-THC (tetrahydrocannabinol). Both measure cannabinoids, but they are not interchangeable. Confusing them is one of the most common procurement errors buyers make when evaluating a Canadian LP's batch data.
What follows explains what each figure represents, how to calculate TPTHC, which number matters in the German, Australian, and Israeli medical channels, and what to ask a supplier when the numbers don't match your requirements.
THCA vs THC: the chemical difference that matters for procurement
THCA is the acid precursor that forms naturally in the cannabis plant during cultivation. Non-psychoactive in raw dried flower, it accounts for the vast majority of the cannabinoid content in any batch. THC (delta-9) is the active compound produced when THCA is heated through decarboxylation.
On an ISO/IEC 17025-accredited COA for dried flower, you'll typically see:
- THCA: 25-30% (the dominant figure in high-potency cultivars)
- delta-9-THC: 0.5-2% (always low in unheated dried flower)
Procurement and import classification both depend on Total Potential THC (TPTHC), calculated as:
TPTHC = (THCA x 0.877) + delta-9-THC
Why 0.877? During decarboxylation, THCA loses a carboxyl group. THCA has a molecular weight of 358.5 g/mol; THC has 314.5 g/mol. Dividing 314.5 by 358.5 gives 0.877 — the conversion used by Health Canada-regulated labs and ISO 17025-accredited testing facilities globally.
Any compliant supplier should report TPTHC alongside raw THCA. If they only report raw THCA, calculate it yourself before making any procurement decision or submitting import documentation.
As a reference point: AlphaLeaf's Ice Cream Cake cultivar (30.3% THC) reflects TPTHC calculated from THCA above 30%, consistent with our ISO-certified batch testing and full traceability records.
How import jurisdictions use cannabinoid potency data
Each medical cannabis market classifies potency differently. Understanding which number each jurisdiction requires prevents documentation errors and shipment holds.
| Jurisdiction | Regulatory body | Potency metric used | Document required | Common hold reason |
|---|---|---|---|---|
| Germany | BfArM | TPTHC (post-decarboxylation) | Bundesopiumstelle import permit + COA | COA shows THCA only, no TPTHC calculated |
| Australia | TGA / ODC | THC concentration (label-matched) | TGA import licence + TGO 93-compliant product description | Mismatch between COA TPTHC and product label THC value |
| Israel | Israeli Medical Cannabis Agency | TPTHC (determines T1-T20 tier) | Import permit + tiered product classification | TPTHC not stated; tier mismatch at pharmacy level |
In Germany, medical cannabis flower is purchased based on total THC content (post-decarboxylation equivalent). Licensed pharmacy distributors need TPTHC on COAs and in import documentation. Submitting raw THCA without a TPTHC calculation risks permit delays at the BfArM.
In Australia, the Therapeutic Goods Administration (TGA) and Office of Drug Control regulate medical cannabis under the Therapeutic Goods Act 1989. Sponsors (importers) are required to match product potency labelling to the permitted product description. A mismatch between COA TPTHC and the label THC value is a documented reason for product holds at the border.
In Israel, the Israeli Medical Cannabis Agency's tiered classification system runs T1 through T20, based on THC concentration. Your batch's TPTHC determines the tier, which determines which patient group a pharmacy may dispense it to. Unambiguous TPTHC reporting is non-negotiable.
One rule applies across all three markets: never submit a COA that shows THCA without the calculated TPTHC figure.
How to evaluate potency consistency across batches
Single-batch potency tells you less than batch-to-batch consistency when setting up a supply relationship. A German pharmacy distributor needs to know whether batch 001's 28.4% TPTHC is repeatable. Impressive first-batch numbers mean little if the next three batches come in 3 points lower.
Before committing to a purchase order, run through what we call The 3-Request Batch Verification Checklist:
- At least three consecutive batch COAs for the same cultivar (sequential, not cherry-picked)
- The standard deviation or TPTHC range across those batches
- The ISO 17025 accreditation number and testing date for the lab that ran each assay
What you're looking for is tight variance. A reliable supplier should show TPTHC variation of no more than 2-3 percentage points across batches of the same cultivar under consistent growing conditions. Variation beyond that points to inconsistent cultivation practices, phenotype instability, or lab methodology differences across testing dates.
Some LPs will hand you a single reference COA from their best batch. That's a marketing document, not a procurement basis. Decisions should rest on a verified sequential batch series.
See also: AlphaLeaf's guide to reading a cannabis certificate of analysis for a full breakdown of what each COA panel covers beyond potency.
CBD and minor cannabinoids: what B2B buyers are starting to request
B2B cannabis procurement has historically focused on THC potency. That's shifting. Several European medical markets, Germany's included, are seeing physician interest in cultivars with defined CBD ratios alongside THC. Prescribing physicians in the German channel increasingly consider the full cannabinoid profile when specifying a product.
Canadian LPs supplying these markets should know what their COA's minor cannabinoid panel shows:
- CBD (cannabidiol): usually below 1% in high-THC cultivars, but some buyers specifically seek cultivars above 5% for defined patient populations
- CBG (cannabigerol): present in trace amounts in mature flower; physician interest is growing in Germany and select EU markets
- CBN (cannabinol): a degradation product of THC. Elevated CBN signals ageing flower or improper storage conditions. See AlphaLeaf's cannabis stability and shelf-life testing guide for acceptable CBN thresholds in export-grade batches
- THCV (tetrahydrocannabivarin): trace presence in most cultivars; occasionally requested in niche Israeli and Australian specialist clinic markets
A reputable ISO 17025-accredited lab reports a full cannabinoid panel. If a COA shows only THCA and CBD, ask your supplier whether their lab runs extended panels. Buyers supplying specialist clinics in Germany or Australia may find full-panel data a practical differentiator within the next two to three years.
For a deeper look at how genetics shape the cannabinoid and terpene profile you'll see on a COA, see AlphaLeaf's cannabis terpene profiles guide for B2B buyers.
AlphaLeaf is a Montreal-based Health Canada Licensed Producer of indoor-grown, hand-trimmed cannabis flower. We hold export authorisation under the Cannabis Act and maintain ISO-certified batch testing, full traceability records, and the compliance documentation that German, Australian, and Israeli importers need when requesting more than a top-line THCA figure.
Frequently Asked Questions
What is the difference between THCA and THC on a cannabis COA?
THCA is the raw acidic precursor found in dried flower before heating. THC (delta-9) is the active compound produced when THCA is heated through decarboxylation. On a COA for dried flower, THCA is always the dominant figure. The potency number relevant to procurement and import classification is Total Potential THC (TPTHC), calculated as (THCA x 0.877) + delta-9-THC.
How do German importers use cannabinoid potency data?
German importers and pharmacy wholesalers need TPTHC values in COA documentation to match against BfArM (Bundesopiumstelle) import permits and pharmacy dispensing records. Raw THCA figures without the calculated TPTHC equivalent can delay permit processing or cause discrepancies at the pharmacy level.
What is the 0.877 conversion factor in cannabis potency calculations?
The 0.877 factor converts THCA to its THC equivalent by accounting for the loss of a carboxyl group during decarboxylation. THCA has a molecular weight of 358.5 g/mol; THC has 314.5 g/mol. Dividing 314.5 by 358.5 gives 0.877 — the conversion used by Health Canada-regulated and ISO 17025-accredited testing labs.
How much potency variance is acceptable across cannabis batches from the same cultivar?
For pharmaceutical-grade B2B supply, TPTHC variance of no more than 2-3 percentage points across consecutive batches of the same cultivar is a reasonable benchmark. Variance beyond that warrants questions about cultivation consistency, phenotype selection, or lab methodology.
Does a higher THC percentage always mean better quality for B2B buyers?
Not for most medical channel applications. Consistency and full cannabinoid panel transparency matter more than peak THCA for German pharmacy distributors and Australian TGA sponsors who need predictable product profiles across multiple shipment cycles.
