When you purchase an edible, the advertising or the packaging will list the THC content, and that will tell you how strong an edible will be. The lowest-strength edible will contain somewhere in the range of 2.5-5 mg of THC, while the most powerful edible might have between 50 and 100 mg of THC. For inexperienced edibles consumers, it’s best to start out on the low side, until you understand how your body will be affected by the dosage of THC in your edible.