Stability testing

Stability testing measures how a product's chemical, physical and microbial characteristics change over time under defined storage conditions.

Samples from a batch are stored at set temperatures and humidities, sometimes with light exposure, and tested at scheduled intervals for cannabinoid content, appearance, odor, texture and microbial growth. Accelerated studies use elevated temperatures to estimate long-term behavior more quickly, while real-time studies run for the full intended shelf life. The data show how fast actives degrade and whether degradation products appear.

The output is the basis for a best-by date and for storage instructions such as keeping a product cool and away from light. It also explains why a fresh batch may test above its label claim if the manufacturer built in an overage. Stability results rarely appear on a consumer-facing certificate of analysis, which reports a single point in time; they are a separate body of data a company may or may not hold. Whether a company has done the work is a fair question to ask.