Well, I think it depends on what meaning one ascribes to the word dimension. Psychedelics can certainly open up more dimensions of perception, to the degree that I consider it a completely different "dimension" of reality.
I can also easily see why people who have been through a DMT ceremony get "very offended" at people who literally don't know what they're talking about (in more than one way) characterize their experiences as simply messed up neuroreceptors. Psychedelic trips can have several different kinds of reality bending phenomenological effects, some of which can have a fair amount of permanence to them, a very common one being extreme empathy and compassion for your fellow man. As someone says says in a different thread [1]:
> I think I experience a lot of stress. I always wanted to change the world growing up, and in the last ten years (I am 36 now) I really learned a lot about how awful some aspects of the world are. I am a deep empath so I have a hard time feeling okay when I know others are suffering. And with the US economy putting the poor at such a disadvantage, I feel pretty unhappy about that stuff all the time. I am in therapy and have been for 8 years, but I still just think a lot of stuff sucks and I can't really ignore that. Just think of the 2 million people in prison in the US. That system needs to change, and it's very easy to learn about that and struggle to not feel okay on the day to day because of that knowledge.
I have had seemingly permanent alterations to my default empathy levels, in large part due to psychedelic usage (at least, I would say it was a prerequisite), and I too get "very offended" when people say objectively incorrect things like "it's just chemicals in your brain", especially when those same people (or the community such conversations take place in) then gets their panties in a knot about how we all have to (or you're an evil person) "do whatever it takes to beat this pandemic" to "save lives"...but then if one is to ask about the lives of people in prison, or dying from drug overdoses or suicide, or war, or malnutrition (in numbers large than global covid deaths despite being geographically concentrated, and this has been happening for decades, and will continue to happen)....well "that's different". First world senior citizens, most of whom have lived a relative life of luxury: spare no expense (literally); third world children: "that's different". Which of these two parties actually has the "messed up neuroreceptors" seems like a valid question to me, but then contemplating such ideas would require actually acting as seriously as we take ourselves to be.
Anyways, best not engage in ideological battles - curious conversation is fine, but not too curious.
[1] https://news.ycombinator.com/item?id=25975887