Okay, you're nervous before a media interview? Should you take a beta blocker, drink alcohol, smoke or consume marijuana? I do get these questions fairly often, believe it or not. And I hate to sound like a prude. I hate to sound like someone who doesn't want anyone to have any fun. But my answer is stay away from all the chemicals before the interview.
If you're nervous, it's probably because you haven't rehearsed enough on video. I know you get tired of me saying that, but it really does solve most problems. Here's the problem with using beta blocker drugs, alcohol or marijuana. You might feel better but you're not going to come across better to the audience. What good is it if you feel better, but you look stoned or bored or boring or low energy or low key or flat? That's gonna make things worse.
I'm more concerned about how you feel watching your interview later than how you feel as it's going. The other problem is, if a news anchor reporter or host or producer smells alcohol on your breath or marijuana that can send a very negative signal to that person they might not ever want to have you on again. I've even seen situations quite embarrassing for the individual on live national TV, where the host said I can smell alcohol on your breath. Have you been drinking? That's the only thing anyone remembered from that interview. So my recommendation, put all the drugs aside.
Use those after the interview if you need them. But before the interview, rely on practicing on video to calm your nerves.