The term "safe" is very subjective, it really depends on what someone means by that. And even then the effects of a particular drug vary greatly from person to person and even trip to trip. If the OP is asking are psychedelics likely to kill you or cause long-term damage to your physical health, then no. The only deaths involving psychedelics I have ever heard of have resulted from mixing more than one drug at once. I have heard of a few mental health issues that are worsened or brought on by the use of psychedelics, but this is really not as common as the media or the US "War on Drugs" would have people believe either. Alternately many people have reported that their mental health issues improved due to the use of psychedelics.
What I would strongly suggest is doing as much research as you can in
reliable sources about the effects, risks, and recommended doses of each particular drug in order to make an educated personal decision about the risk level and whether that risk level is acceptable to you. There is a ton of info easily available online. As with any activity, it is an individual decision about whether it is healthy or not for
you. I always suggest being very careful about doses with any drug (including "natural" or plant-based drugs). Taking too much of one specific psychedelic has rarely, if ever, actually killed someone, but that doesn't mean it's a good idea. It's always better to take "not enough" than too much
EDIT: One thing I forgot to mention is that there can of course be risks from getting drugs that have something harmful mixed in with them or are not what they are supposed to be, but that is a whole other topic. I assumed the OP meant theoretically assuming that the drugs in question are what they are supposed to be and are reasonably pure.