What Is Cannabis Potency? THC, CBD, and Lab Numbers

What cannabis potency means

Cannabis potency is the concentration of active compounds in a product. The main active compound is delta-9-tetrahydrocannabinol, or THC. A second compound is cannabidiol, or CBD. Potency for flower is a percentage of dry weight. Potency for edibles and concentrates is milligrams of THC per item or per serving.

How labs measure potency

Labs use high-performance liquid chromatography (HPLC) or gas chromatography (GC). HPLC measures THC and THCA as two numbers. THCA is the acidic form of THC. THCA has no psychoactive effect until heat converts it. Smoking, vaping, or baking converts THCA to THC. This step is decarboxylation. GC converts THCA to THC during the test. GC reports total THC.

Typical potency numbers

Flower in the 1960s: 1% to 3% THC.
Flower in the 1990s: about 4% THC.
Flower in the 2020s: 15% to 30% THC.
Concentrates: 50% to 90% THC.
Edibles: 5 mg to 10 mg THC per serving in many US states.

Potency is not dose

Potency describes concentration. Dose describes the amount a person takes. One gram of 20% THC flower holds about 200 mg of THC. Not all of it reaches the bloodstream. Inhaled cannabis delivers about 10% to 25% of THC. Oral cannabis has lower and slower absorption. A 10 mg edible can produce stronger effects than a few puffs of high-potency flower.

cannabis potency vs effect

Label accuracy

State labs test products, but studies find mismatches. A 2015 analysis in JAMA found that many edible labels listed THC content that differed from lab results. Some products had less THC than stated. Others had more. Consumers cannot confirm potency without a lab test. Product labels from licensed sellers in states with testing rules carry batch numbers and test dates.