More than half of adults in the United States have received at least one dose of a Covid-19 vaccine. With second doses incoming and millions more to soon be immunized, many wonder if it is safe to celebrate their Covid shot with a booze shot.

Marijuana smokers who use the plant as a pain and anxiety reliever may also turn to the herb as a treatment for side effects.

Bars across the country are offering free beer if patrons provide proof of immunization, with some bars in New Jersey even offering a beer on site during inoculation.

“A glass of wine or a beer is OK, but heavy alcohol intake can suppress your immune system and should be avoided in general. As always, moderation is the key,” Katherine Yang, a clinical professor of pharmacy at the University of California San Francisco told CNBC.

Dr. Anne Liu, an infectious disease physician at Stanford Health told CNBC that a celebratory drink or two is totally fine, and it doesn’t make a difference if you drink on the day of the vaccine or a week later.

“Certainly when people drink enough to affect their liver, that can affect their immune system,” Liu said. “The liver is a very important organ in terms of having a normal immune response, and people who have poor liver function for various reasons may not respond well to the vaccine and in general are probably at a higher risk of complication from Covid,” she said.

As for marijuana, it depends on the form of consumption. Marijuana can be consumed in a variety of ways from foods, to vapor, to smoke and more. Cigarette smokers are particularly at risk for complications with Covid-19.

“Smoking has specific effects on blood vessels and the cardiovascular system,” Liu said. “What is not necessarily the case with other respiratory viruses and has clearly been the case with Covid is that people with disorders of blood vessels and the cardiovascular system are at much higher risk of complications with Covid, which is why smokers were high priority in some places for getting the vaccine,” she said.

Consuming marijuana in ways other than smoking is probably fine: “While there aren’t any studies on the effect of marijuana and Covid vaccine, it is unlikely to affect the immune response to vaccine,” Yang said. “It is possible, however, that marijuana or wine could make any side effects to the vaccine such as headache, nausea or achiness worse so that is something to watch out for.”

As for harder drugs like cocaine or ecstasy, Liu said we probably don’t know enough to be able to say whether it is safe or not.

“Anything in modest amounts of those substances are unlikely to significantly impair your immune system … but it becomes much less predictable. If it’s something you use recreationally, maybe just skip it that day, getting a vaccine is celebration enough,” she said.

The general consensus among experts is that when it comes to consuming marijuana or alcohol, moderation is key. If a person consumes these substances on a regular basis already, then pouring one out or rolling one up on the day of your vaccination, is probably fine.