Illinois patients legally purchased $2.9 million worth of medical marijuana products in July.
State officials with the medical cannabis pilot program released the figures Wednesday. June sales had been $2.57 million.
Sales have climbed steadily since purchasing began Nov. 9.
Illinois now has nearly 8,891 qualified medical marijuana patients and 40 registered dispensaries.
July's figures bring the total retail sales of marijuana in Illinois to $16.3 million.
Recent changes in the medical marijuana law required updates to patient paperwork. The Illinois Department of Public Health posted new forms this week for doctors and patients.
The new material includes a form physicians must use to certify that a patient has a qualifying health condition.
A doctors recommendation for marijuana no longer is required, but a physician must certify a patient's diagnosis.