Current U.S. State Cannabis Sales Limits Allow Large Doses for Use or Diversion

Introduction Legal limits on the amount of cannabis sold per transaction in states with recreational cannabis may promote moderate use and limit diversion. However, state sales limits are heterogeneous and difficult to interpret in terms of tetrahydrocannabinol dose equivalents. Methods This cross-sectional study examined how transaction sales limits on recreational cannabis translate to tetrahydrocannabinol doses among U.S. states allowing commercial cannabis sales as of January 1, 2020. Weight-based quantity limits by cannabis type (flower/bud, concentrates, and edibles) were converted into grams of tetrahydrocannabinol content per transaction using known potency values in 2020. Results Weight-based sales limits for flower and concentrate vary considerably across states (range=1.0–2.5 oz for flower and 3.5–15.0 g for concentrate), whereas limits for edible cannabis are heterogeneous. A total of 4 states have independent limits for each product category, and 6 states place limits across all products sold in the transaction. Because no states impose limits on the potency of flower or concentrates, the small differences in the weight-based limits translate into large differences in grams of tetrahydrocannabinol allowed to be sold. Assuming a typical dose of 10 mg of tetrahydrocannabinol, current laws allow for sales of up to 560 (Alaska) to 2,283 (Michigan) doses per transaction on the basis of median product potencies. Conclusions All states allow a large number of tetrahydrocannabinol doses per transaction, larger than what is typically consumed by daily users over a month. States concerned about public health and diversion should consider reducing sales limits and basing them on total tetrahydrocannabinol content across all purchased products.