U.S. Surgeon General Jerome Adams said he supports medical cannabis research, but still opposes social use legalization.

According to Adams, who spoke at the National Black Caucus of State Legislators’ annual conference in Indianapolis, medical cannabis “should be like any other drug.”

“We need to let the FDA study it, vet it. The FDA has actually approved cannabidiol oil and some derivatives of marijuana,” he said.

Although Adams showed support toward medical cannabis, he still expressed reservations about the potential risks of the plant’s use. Cannabis is not one substance, he said, but it is over 100 different substances, some of which benefit, some of which are harmful.

In addition, he said the Surgeon General’s office has traditionally opposed cigarette smoking, and he goes along with the same belief.

“How am I going to tell you not to smoke a cigarette but I am going to tell you to pick up a joint? I can’t do it, can’t do it,” he said. “I don’t want 10 years down the road where we’re seeing an epidemic of lung cancer among folks who are smoking medical marijuana.”

Medical cannabis can be consumed in different ways that do not only involve smoking it, and some states that have approved medical cannabis actually prohibited smoking the plant.

At the conference, Adams told the attendees, “While I want to make sure we can get the ingredients of medical marijuana appropriately derived so that folks can access treatment, I also have concerns about us encouraging folks to go out and smoke because there’s unintended consequences.”

Adams’ view on the use of medical cannabis is similar to Obama-era Surgeon General Vivek Murthy, who said the government’s policy on cannabis should be driven by scientific facts.

“Marijuana policy — and all public health policies — should be driven by science,” Murthy said. “I believe that marijuana should be subjected to the same, rigorous clinical trials and scientific scrutiny that the Food and Drug Administration (FDA) applies to all new medications.”

Just like Adams, he also talked about the dangers of smoking cannabis.

“While clinical trials for certain components of marijuana appear promising for some medical conditions,” Murthy said in 2015. “Neither the FDA nor the Institute of Medicine have found smoked marijuana to meet the standards for safe and effective medicine for any condition to date.”