; and the additional quantity of each desired. Upon return of the receipt, the registrant shall be authorized to purchase and use the additional quantity of the controlled substance or substances specified in the request. (d) In the event the registrant desires to conduct research beyond the variations provided in the registrant's approved protocol (excluding any increase in the quantity of the controlled substance requested for his/her research project as outlined in paragraph (c) of this section), he/she shall submit three copies by registered mail, with a return receipt requested, of a supplemental protocol in accordance with paragraph (a) of this section describing the new research and omitting information in the supplemental protocol which has been stated in the original protocol. Unless explicitly denied, supplemental protocols shall be considered approved 30 days after the date on which the return receipt is returned. . 5. Medical research on cannabidiol (a) In general Notwithstanding any provision of the Controlled Substances Act ( 21 U.S.C. 801 et seq.), the Safe and Drug-Free Schools and Communities Act ( 20 U.S.C. 7101 et seq.), chapter 81 of title 41, United States Code, or any other Federal law, an appropriately registered covered institution of higher education, a practitioner, or a manufacturer may manufacture, distribute, dispense, or possess marihuana or cannabidiol if the marihuana or cannabidiol is manufactured, distributed, dispensed, or possessed, respectively, for purposes of authorized medical research. (b) Registration for research involving cannabidiol (1) Initial period During the period beginning on the date of enactment of this Act and ending on the date on which the Attorney General makes a determination regarding control of cannabidiol, an individual or entity engaged in authorized medical research may distribute, dispense, or possess cannabidiol for purposes of the authorized medical research if the individual or entity is registered under the Controlled Substances Act ( 21 U.S.C.