Ehrlich's reagent will tell you if you have something in at least the same chemical family as LSD, which rules out almost all of the dangerous substances that are sometimes sold as "LSD."
LSD does cause anxiety for many, often at the beginning of the trip. I know when it's kicked in because I get a big rush of anxiety that slowly fades over time. So I wouldn't recommend it to people with an uncontrolled anxiety disorder. (If you can control your anxiety, it can be great and quite therapeutic.)
I have anxiety and it’s not been a major issue for me when using LSD.. But I’m experienced in practicing mindfulness which helps tremendously. The anxiety tends to happen at the beginning of the trip so I remind myself that it’s just the acid and things will be awesome once I ride out the anxiety. For higher doses I usually meditate while the trip comes up.
Not that I haven’t had a bad trip, but when I did it was a result of a clear failure to respect set and setting. Changing the setting put things back on track so I’d characterize it as a “meh” trip rather than a bad one.
Often I experience a massive reduction in anxiety for several weeks following a trip so overall I’d say it’s been very beneficial for me.