A Massachusetts physician should not have had his medical license suspended for allowing nurse practitioners in his office to certify patients for medical marijuana use, according to a state administrative law judge.

Regulators in May suspended the license of Dr. John C. Nadolny, medical director of Canna Care Docs, a practice with eight Massachusetts locations that specialize in screening and approving patients for marijuana use.

The Board of Registration in Medicine had ruled that Nadolny was an immediate threat to public safety, saying his office improperly used nurse practitioners to certify that thousands of patients were eligible to receive medical marijuana.