Terpene panels and quality labels

On most COAs, cannabinoid and terpene values appear side by side, as if they were equivalent measurements. Chemically, they are not: terpenes are significantly more volatile than cannabinoids like THC or CBD. They evaporate and react with oxygen even during normal sample handling – transport, interim storage, grinding the sample, time between harvest and testing – to an extent that barely affects cannabinoids in the same timeframe.

In practice, this means: the terpene value on a COA is far more time- and method-dependent than the cannabinoid value right next to it – even if both come from the same sample, on the same day, at the same lab.

This exact point is also behind the previously mentioned recommendation from Raeber et al. (2025, see article Terpene oxidation products and their significance): terpenes should be reported as a quantitative concentration rather than a normalized percentage, because normalization can disguise real losses as a mere 'profile shift'.

A typical terpene panel lists the individual shares of the measured terpenes as well as a sum, usually referred to as 'Total Terpenes'.

Rough reference values circulating in the industry (informal estimates, not official standard values): flowering typically runs at about 1 to 4% total terpenes relative to dry weight. Values around 2 to 3% are considered solid and aromatic by many sellers, values above 3% are often informally marketed as exceptional.

Concentrates vary much more widely – roughly in the range of 3 to 12%. Live resin and live rosin, which are specifically designed to preserve terpenes, can reach 8 to over 20%.

HTFSE stands for High Terpene Full Spectrum Extract, a term originally coined by the Oregon-based company Extractioneering. It is defined by the process, not by the genetics: the starting material is fresh-frozen rather than dried and cured plant material, extracted under conditions designed to pull out as few waxes and fats as possible – these companion substances would otherwise put additional strain on the sensitive terpenes during later processing. HTFSE typically contains about 13 to 40% terpenes at around 50% THCA – terpene preservation is thus deliberately traded for a lower raw cannabinoid content.

HCFSE (High Cannabinoid Full Spectrum Extract) is the counterpart within the same product family: the process instead targets the highest possible cannabinoid share, often around 90% THCA, with a more sugary, diamond-like texture instead of the more sauce- or liquid-like consistency of HTFSE.

Important for context: HTFSE and HCFSE are not different strains or genetics, but two ends of the same processing spectrum – the same starting plant can be processed more toward one direction or the other depending on how the process is run.

Unlike, say, THC thresholds, there is no uniform, regulated threshold for the term 'terpene-rich'. Labs, manufacturers, and shops use it inconsistently – what one supplier markets as terpene-rich might be standard at another.

Addiction medicine and pharmacology also regularly express skepticism toward claims that link individual terpenes to specific therapeutic effects – such attributions are often classified there as 'largely anecdotal', not as clinically established.

The pragmatic consequence: treat a high terpene value primarily as an aroma and flavor indicator, not as a reliable predictor of effect. And prioritize a genuine, independent certificate of analysis over marketing copy on packaging or a website.

Alongside the sheer volatility, there is a second source of imprecision: inconsistent lab methodology. Trade press coverage (of medium reliability, better classified as an observed trend than as solid statistics) repeatedly points to noticeable differences in testing procedures between labs – for example headspace methods (which measure terpenes from the gas phase above the sample) versus direct injection methods, which can yield markedly different values on the same sample.

Unlike cannabinoid potency measurement, for which established ring tests and certification standards exist in many regions, there is so far no comparably widespread, terpene-specific testing standard. This explains part of the variation you see when two labs rate the same batch differently.

A high reported terpene value is ultimately only as trustworthy as three background factors: how fresh the sample actually was at the time of testing, whether the lab used terpene-appropriate rather than merely cannabinoid-appropriate sample handling, and whether the value is reported as a quantitative concentration rather than a normalized percentage.