Sacramento, California - California Governor Gavin Newsom on Saturday vetoed a bill that would decriminalize psychedelics in the state.

The legislation, Senate Bill 58, would have removed criminal penalties for people in possession of natural hallucinogenic substances, including mescaline, dimethyltryptamine (DMT), psilocybin, and psilocyn, starting in 2025.

Cities in the state, including Oakland, San Francisco, Santa Cruz, and Berkeley, have already taken the step of decriminalizing natural psychedelics that come from plants and fungi.

Though Newsom acknowledged the exciting medical potential of psychedelic therapies, he said more work would have to be done before he would sign the bill into law.

Donald Trump Donald Trump spills all about what he plans to do if he wins re-election

"California should immediately begin work to set up regulated treatment guidelines – replete with dosing information, therapeutic guidelines, rules to prevent against exploitation during guided treatments, and medical clearance of no underlying psychoses," the governor said in his veto message. "Unfortunately, this bill would decriminalize possession prior to these guidelines going into place, and I cannot sign it."

"I urge the legislature to send me legislation next year that includes therapeutic guidelines," he added.

Even though Newsom shot down Senate Bill 58, Californians may get the opportunity to have their say on psychedelic decriminalization in 2024, as advocates push for ballot measures to legalize mushrooms for people ages 21 and up and to approve funding for a state agency to research psychedelic therapies.