# Potency testing

> Potency testing is laboratory measurement of a sample's cannabinoid content, normally by HPLC, reported as % w/w or mg/g for each cannabinoid plus calculated totals.

- Canonical: https://genetixbay.com/knowledge/glossary/potency-testing.html
- Also written: potency test, cannabinoid testing, cannabinoid profile test, THC test, potency analysis, cannabinoid potency
- Glossary category: Lab testing · Evidence: Established
- Status: Draft: awaiting expert review · Updated: 2026-10-31
- Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay cannabis glossary"

Potency testing quantifies the [cannabinoids](https://genetixbay.com/knowledge/glossary/cannabinoid.md) in a sample. The standard approach is [high-performance liquid chromatography](https://genetixbay.com/knowledge/glossary/hplc.md) with UV detection (HPLC-UV), which measures acid and [neutral cannabinoids](https://genetixbay.com/knowledge/glossary/acid-vs-neutral-cannabinoids.md) separately without heating them. The lab weighs a homogenised portion, extracts it with solvent, runs it against calibrated reference standards and reports each compound and the calculated totals.

## In practice

Results depend heavily on steps before the instrument: which buds were sampled, how well they were ground and mixed, whether moisture was corrected, and how the lab calibrates. Jikomes and Zoorob (2018) showed that results in a regulated market differed systematically between labs, and Schwabe et al. (2023) found many retail labels well above independently measured values. For a home grower, one test of a well-mixed sample of several buds is far more useful than a single [top cola](https://genetixbay.com/knowledge/glossary/cola.md).

## Don't confuse with

- **Terpene test**: measures aroma compounds, usually by [GC](https://genetixbay.com/knowledge/glossary/gas-chromatography.md).
- **Genotyping**: reads DNA, can predict [chemotype](https://genetixbay.com/knowledge/glossary/chemotype.md) class but not percentage.
- **Home test kits**: colour or thin-layer kits give rough estimates, not COA-grade numbers.

## Myth check

A higher number from a different lab is not proof of a better plant. See [buyer beware](https://genetixbay.com/knowledge/basics/buyer-beware-label-claims.md).

## Related terms

[HPLC](https://genetixbay.com/knowledge/glossary/hplc.md), [Total THC](https://genetixbay.com/knowledge/glossary/total-thc.md), [COA](https://genetixbay.com/knowledge/glossary/coa.md), [Homogenisation (sampling)](https://genetixbay.com/knowledge/glossary/homogenisation.md), [Measurement uncertainty](https://genetixbay.com/knowledge/glossary/measurement-uncertainty.md), [Label inflation](https://genetixbay.com/knowledge/glossary/label-inflation.md)

## Read more

- [Buyer beware: potency labels, strain names and other claims that don't hold up](https://genetixbay.com/knowledge/basics/buyer-beware-label-claims.md)

## Sources

1. Jikomes N, Zoorob M. 2018. The cannabinoid content of legal cannabis in Washington State varies systematically across testing facilities and popular consumer products. Scientific Reports 8:4519. https://doi.org/10.1038/s41598-018-22755-2
2. Schwabe AL, Johnson V, Harrelson J, McGlaughlin ME. 2023. Uncomfortably high: Testing reveals inflated THC potency on retail Cannabis labels. PLOS ONE 18(4):e0282396. https://doi.org/10.1371/journal.pone.0282396
3. Berman P, Futoran K, Lewitus GM, Mukha D, Benami M, Shlomi T, Meiri D. 2018. A new ESI-LC/MS approach for comprehensive metabolic profiling of phytocannabinoids in Cannabis. Scientific Reports 8:14280. https://doi.org/10.1038/s41598-018-32651-4