Cal. Health and Safety Code § 111470

The following drugs or devices, that are intended for use by man, shall be sold only upon a written prescription of a practitioner licensed by law to prescribe the drug or device, or upon an oral prescription of the licensee that is reduced promptly to writing and filed by the pharmacist, or by refilling the written or oral prescription if the refilling is authorized by the prescriber either in the original prescription or by oral order that is reduced promptly to writing and filed by the pharmacist: (a) A habit forming drug to which Section 111350 applies. (b) A drug or device that, because of its toxicity or other potentiality for harmful effect, or the method of its use, or the collateral measures necessary to its use, is not safe for use except under the supervision of a practitioner licensed by law to administer the drug or device. (c) A drug or device for which adequate directions cannot be written for persons, who are not practitioners licensed by law to prescribe the drug or device, for safe and effective self-medication or treatment by those persons, who are not practitioners licensed by law to prescribe the drug or device. (d) A drug or device that is limited by an effective application under Section 505 of the federal act (21 U.S.C. Sec. 355) or Section 111550 to use under the professional supervision of a practitioner licensed by law to administer the drug or device. If any prescription for the drug does not indicate the number of times it may be refilled, if any, the prescription may not be refilled unless the pharmacist obtains a new order from the practitioner.