Mexico just approved a major change to its drug policy
The bill, part of a proposal that President Enrique Pena Nieto submitted to Congress earlier this year, must also be passed by Mexico's lower house to become law.
The measure passed 98-7.
Since a court ruling last year, the government has allowed the importation on a case-by-case basis of medicine with cannabidiol (CBD), an active chemical ingredient of the drug.
The bill passed on Tuesday envisages permitting use of products containing the psychoactive ingredient tetrahydrocannabinol (THC).
The measure would also allow for production of marijuana for scientific and medicinal purposes.
"It's been years that we've been fighting for acknowledgment and approval and recognition of the medical and therapeutic uses of cannabis, and today we finally have something," said Lisa Sanchez, director of drug policy for Mexico Unido Contra la Delincuencia, a group working to curb crime.
Tuesday's decision was "not the end of the road," she added.
Recreational marijuana is still broadly prohibited in Mexico, and less than one-third of people there support legalization. But last year the Supreme Court granted four people the right to grow their own marijuana for personal consumption, opening the door to legalization.
In April this year, Peña Nieto broached loosening Mexico's marijuana restrictions. His proposal not only included medical marijuana but also an increase of the amount of the drug a person can carry, up to an ounce. That initiative stalled in June, held up by Peña Nieto's own party.
The wave of legalizations for medical and recreational marijuana in the US has caught the attention of policymakers in Mexico. Prior to November elections in the US, Peña Nieto and other Mexican officials were reportedly "paying close attention" to California's legalization drive.
Loosening of restrictions on marijuana in the US has reportedly cut into the profits of Mexican drug-trafficking organizations, and the legal distribution of high-quality of marijuana in California has raised the possibility that the drug may soon be smuggled into Mexico.
(Reporting for Reuters by Joanna Zuckerman Bernstein; Editing by Lisa Shumaker)