Now, any RC dissociative like 3-meo-pcp, 4-meo-pcp, and methoxetamine are not researched fully, or hardly at all and need to be treated with up most caution. Lets not pretend that any dissociative/NMDA-antagonist is completely safe, especially those that are research chemicals.
With PCP being potentially neurotoxic I'd always assume that any research chemical dissociative is potentially neurotoxic; with ketamine it has been researched that there is no permanent damage, and Osley's Lesions have been proven against in primates and humans due to having a highly different metabolism then rats, but this safety for ketamine is caused by it being a bit of a 'receptor slut' especially at higher dosages. I'd assume that is the true narcosis it causes at higher doses which is NOT found in many of the RC dissociatives, thus I'd assume there is a fair chance that those (like methoxetamine, 3-meo-pcp etc.) could be more harmful with prolonged use.
To answer the question of the topic starter; I can only speak for ketamine and nitrous oxide, but plenty of people already spoke for DXM so I assume that's fine. For ketamine the long term effects would be much deeper understanding and knowledge of your own conciousness, mind, personality and such. It is a great, if not one of the best, tool for self exploration and understanding. A lot can be learned from the dissociative state, also in terms of philosophy. It has high 'psychonaut' value if used properly, bút it is also properly addictive for many people. The effects are consistent, highly serene, beautiful, véry safe feeling and escapist. Fear is simply not possible as you are dissociated from emotions. Only serenity and possibly wonder prevail. If you have any real reason for escapism in your life this could véry easily cause addiction.
It also interfers with word recall and memory formation, the only thing I noticed that persists after all ketamine effects have worn of is the word recall issue. This can last up to 5 days for me after a heavy and prolonged ketamine binge. I'm pretty sure the fact this lasta for a few days has to do with the fact there is still metabolites (norketamine) in the blood, which is still a dissociative. This can have you feeling semi-dissociated for days after a heavy more-then-one-day binge BUT it is not permanent damage. If you take a long enough break it wíll return to normal. So there is no real permanent brain damage, but temporarely loss of efficienty for certain functions.
Then there's the bladder damage; nor ketamine is damaging on the bladder and causes scar tissue. This doesn't heal easily on itself and cán be very problematic. However, if you keep your usage below or at once a week at most, it will not happen. Also, paying attention to your water intake makes a real difference. If bladder damage has occured and a person keeps a daily habbit of multiple grams up it can work up to kidney damage, which is even worse. That's some good reasons to not get addicted to ketamine.
Still as a tool for self exploration, conciousness exploration, relaxation, hedonistic pleasure or synchronising your subconciouss with that of another individual also on ketamine (it can be só deep, só very psychedelic) it is really, really wonderful. The k-hole is beautiful too. It's a wonderful tool for creativity, inspiration and absurdism and surrealism too. The dissociative state by nature is absurdistic, and if you're into absurdist art (I am very very much so) it has a lot of advantages.
Also; the fact there is no permanent brain damage, just temporarely fails of the word recall until you take a long enough break and the fact the only organ it is really nasty to is the bladder and only with repeated seriously high doses for a longer amount of time, still makes it fairly safe. I'd say out of all dissociatives with current knowledge of them, it is probably one of the safest to experiment with. It's nearly impossible to overdose, and unless you use more then a gram a day for months or years you are unlikely to ever have a lasting negative side effect at all. Out of all currently known dissociative I'd say with some certainty ketamine has the best safety profile, with overdose being close to impossible, brain damage being pretty much proven against (serveral different studies all show that ketamine 'damage' reverses if you take a long enough break, thus it being not actual damage but more the metabolites interfering with normal brain function) and organ damage being very unlikely unless you really overdo it. I'd say once or twice a month is pretty much safe and really all you need if you want to do it for exploration, inspiration and occasional fun.
The only problem is making sure you don't become a more-then-a-gram-a-day user, which the first few months or years or ketamine use may seem 'impossible' since 'how could one function in such a state', well believe me, it IS possible. In june and july I found myself using about half a gram a day, for up to 9 days in a row with occasional one or two week breaks. Strange enough, functioning on ketamine is possible once you're used to the effects enough. Not because of tolerance, as 40-50 mg gets me decent effects, 80-120 mg gets me very strong effects and 250-300 mg is a guaranteed K-hole, but because I know the state so well. Any motoric function I'm used to doing, like rolling a joint, drawing, speaking, walking, drinking water etc. I can do up to the point where I litteraly can't move, which is only in a K-hole, meaning that as long as I'm not in an actual K-hole I can function at home or at parties or at a festival. I can also stand and walk on the combination of ketamine and 3-4 whippits of nitrous, most people twice my size fall over while subjectively still being less overwhelmed by the intensity. It's pure habituation, just like holding a deep conversation with a stranger about a deep subject on LSD is much easier the 50th trip compared to the 5th or so, it's not tolerance, it's getting familiar with the effects.
So yeah if you want to safely explore dissociation I would advise ketamine as best option, but I'd advise to keep usage at most at twice a month to prevent addiction.
