Potency is the dose per gram
Potency is the amount of THC in a product. The THC percentage tells you how much of the flower, oil, or edible is active cannabinoid. One gram of flower at 20% THC holds 200 mg of THC. One gram at 10% holds 100 mg. A puff from a cartridge at 80% THC delivers about eight times the THC of a puff from 10% flower at the same volume.
That number drives three things: dose control, cost per milligram, and tolerance.
how to test cannabis potency at home
How THC content is measured
Raw cannabis holds most THC as THCA, an acid form with no psychoactive effect. Heat converts THCA to THC and releases carbon dioxide. The conversion drops about 12% of the mass. A lab reports THCA and THC on the certificate of analysis. To estimate total THC, multiply THCA by 0.877 and add the THC number.
A label that lists 30% THCA is not a 30% THC product. Total THC lands near 26%.
THC vs CBD: Understanding Potency Differences
Typical potency ranges
- Flower: 15% to 30% total THC in most legal markets.
- Vape cartridges and concentrates: 60% to 90% THC.
- Hash and kief: 20% to 60% THC.
- Edibles: fixed per package, with most states capping servings at 10 mg THC and packages at 100 mg.
- Tinctures: variable, often 1 mg to 5 mg THC per drop or pump.
Government samples from the 1970s put average flower under 2% THC. The shift to 20% and higher changes how much THC a person takes in one session.
Potency and dose response
THC effects follow a biphasic curve. Low doses can ease nausea, pain, and anxiety. High doses raise the odds of paranoia, rapid heart rate, and vomiting. A 5 mg edible and a 50 mg edible are not the same experience at two strengths. They sit on different parts of the curve.
Route changes the math. Inhaled THC reaches the blood in seconds and peaks in minutes. Oral THC passes through the liver and forms 11-hydroxy-THC, a metabolite with stronger effects. Oral bioavailability sits near 4% to 20%. Onset takes 30 to 120 minutes. People who redose at 20 minutes because nothing has happened overshoot the target dose.
Potency and tolerance
Daily high-dose use desensitizes CB1 receptors. The result is a need for more THC for the same effect. Consumers who move from 15% flower to 25% flower often report that the older product does nothing. A tolerance break of 2 to 4 weeks lowers the threshold again.
Potency and label accuracy
Testing rules vary by state, and states set their own variance limits between the label and the lab result. A 2015 study in JAMA tested 75 edible products and found 17 within 10% of the labeled THC amount. Some products held less than 1% of the stated THC. Others held more than double.
This matters for dosing. A buyer who plans a 10 mg dose may take 25 mg instead.
Potency and price
Price per milligram of THC is the useful comparison. An eighth (3.5 g) at 20% THC holds 700 mg of THC. The same eighth at 30% holds 1,050 mg. At $40 for either jar, the stronger one costs less per milligram.
What to check on a label
- Total THC, not THCA alone.
- Batch date and test date.
- Package total and serving size in milligrams.
- CBD and minor cannabinoid content.
- Terpene profile, if listed.
Potency is one input. Terpenes, cannabinoid ratio, and delivery method also shape the effect. Start low, measure the dose in milligrams, and keep the package for reference.