The 3D Cannabis Center in Denver, which was among the first retailers open last Wednesday, closed on Monday and Tuesday to restock after high demand sapped supplies. A message on the store's phone line directed customers toother dispensaries that were still open.
BotanaCare in the suburb of Northglenn said it had a 15-minute queue on Monday morning for recreational sales, but no wait on its medical side.
Industry watchers said they expected supply and demand to even out as many retailers who were waiting out the initial rush joined the market.
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"Given that several additional stores are opening each day and the novelty of being one of the first purchasers is ending, any statewide shortage (if it happens) is probably a few weeks away," Ms Aldworth said.
Alicia Contreras of Denver's Timberline Herbal Clinic said her dispensary was granted its retail licence late last Friday, earlier than it had expected, and did not have any queues yet. "We are open, but people might not know," she said. "We're sort of under the radar."
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Colorado became the first state to allow sales of the drug for recreational use when voters approved a referendum in 2012. Voters in Washington state passed a similar law but sales will not start till later this year.
Twenty states and the District of Columbia permit medical marijuana, with New York set to become the 21st. The drug remains illegal under federal law.