Is there a law that prohibits controlled substance services for 90 days?

There is no specific law that prevents a pharmacist from dispensing a controlled substance for more than 30 days at a time. However, the pharmacist must follow the directions provided by the prescribing doctor on the prescription. If the prescription specifies a certain quantity to be dispensed at once, the pharmacist must adhere to that. Generally, pharmacists may also use their professional judgment to dispense a smaller quantity than requested by the patient.