A section of the Medical Marijuana Program (Health & Saf. Code, sec. 11362.7 et seq.) quantifying the amount of marijuana that can legally be possessed is invalid under the California Constitution because it impermissibly amends the Compassionate Use Act, which was passed by initiative. The Compassionate Use Act, which provides an affirmative defense to prosecution for the crimes of possession and cultivation of marijuana for those who use the drug in a medical context, was passed by initiative (Proposition 215). The act does not quantify the amount of marijuana that can be possessed, or cultivated, stating that it must be for the patients current medical purposes. The Legislature subsequently enacted the MMP (Health & Saf. Code, sec. 11362.7 et seq.), which added new code sections addressing the general subject matter covered by the CUA. Included in these provisions is one which establishes the specific amounts of marijuana that can be possessed by a qualified patient or caregiver. The Supreme Court provided a lengthy discussion of the initiative process and observed that in California, unless the initial initiative provides otherwise, an initiative provision can only be amended by the Legislature with another statute that becomes effective when approved by the electorate. Here, the CUA did not grant the Legislature authority to amend it, and the Legislature did not propose the MMP and then submit it to the electorate for approval. Because the section of the MMP designating amounts of marijuana permissible by those who can possess it effectuates a change in the CUA that takes away rights granted by the initial scheme, it improperly amends the CUA in violation of the California Constitution. The Court held, however, that section 11362.7, need not be severed from the MMP and voided in its entirety. Only that portion of the statute that impermissibly amends the CUA by burdening a defense otherwise available under the CUA is disallowed.