The first few times I used MXE I experienced effects that, If one to describe them to someone else, would sound like they were describing an opiate... analgesia, a pleasant body numbness, relaxation, a warmth in the limbs like a gentle massage etc. Despite the similarity in the effects, they were in every way, qualitively different to an opiate. It's easy to see how someone who is perhaps not very experienced with an opate high couid mistake this for μ activity. This opiate like effect seems to disappear quite quickly with tolerance, even faster than MXE's stimulating effects. At least with the DRI stim effect, absence for a couple weeks is enough to feel it again. But other than those first few experiences, I've only gotten the opiate-like effects when having abstained for a couple months or more, and then tolerance going right back up again with one dose!
I have to agree with limonov with MXE's ability to potentiate opiates!. I'm a huge fan of poppy pods and prefer them to even pure morphine due the gentle stimulation and motivational effects, and sheer versatility of the high. I first started with pods when I had next to no opiate tolerance, just a couple experiences with tramadol, with codeine, and few disappointing experiments with kratom. MXE hit the market shortly after and although I'ver never been particularly interested in dissociatives, I was interested in the tolerance prevention of NMDA antagonists.
Initially, my tolerance grew fairly rapidly from needing 2 large gigantheum pods to get fairly high to needing 4-5. This was from using roughly bi-weekly for about a month. I then started taking threshold doses of MXE every time I used the pods. The first thing I noticed about this combination was the intensity of the mental euphoria. I wouldn't necessarily say it potentiated the high as a whole, but rather focused mostly on a particular element of it that felt predominantely dopaminergic in nature,. I felt particularly confident, sociable and surprisingly energetic. This was more than just the DRI effect of the MXE too, as it felt much more like the stimulant effect of poppy pods than of MXE. Over time the potentiation seemed to become somewhat more wholesome, rather than predominantely stimulating
I continued using pods an average of twice a week for a good few months, taking threshold doses of MXE every time. In that time my dose went from 4-5 pods to 6-8 for a fairly strong dose. At some point I ran out of MXE and just didn't bother with it any more... silly really. I carried on usig the pods and my tolerance went through the roof! A few months later, having even taken a month or so out to try and let my tolerance drop and limiting myself to once a week, I was taking 10-12 pods to get high. At this point I started using the MXE again, but It was nowhere near as effective as it once was at preventing tolerance.
I assume that its effectiveness at preventing tolerance is dependant upon doses used, so the higher the opiate dose, the more NMDA antagonist required to counter the increase in tolerance. Unfortunately, there is only so high you can go with the MXE dose. Whilst threshold doses potentiate some aspects of the high, dissociative doses will ruin an otherwise amazing opiate experience. The dissociative mental effects of the MXE overpower the subtle, yet all compasing, warm, peaceful mental effects of the opiate. I've been using pods now, taking a couple 1-2 month breaks for 16 or so months and require about 15 pods. I've struck a nice balance of occaisional use with MXE, with the odd break that seems to keep tolerance fairly steady, although still on the increase. I've not had any in about 2 months, and probably won't get any more for another month at least. It'll be interesting to see how my tolerance is doing after this fairly long break.
Oh, and MXE (and probably other NMDA antagonists) don't appear to actually lower tolerance, only prevent it. Or at least Slow it down. Other folk may find it's even more effective than I depending on their opiate of choice. Thanks to enzyme saturation, the pod high lasts an incredibly long time with a peak lasting around 6 hours (although highly dose dependant) followed by a slow decline in effects in which you can still feel a definate opiate effect more than 24 hours later. Since you'll likely enter a long, noddy sleep for 12+ hours following the initial peak, you'll not be redosiing on the MXE for some time. Pods are notorious for causing tolerance to sktrocket due to the incredible amount of time it can take to clear the morphine from ones system.
Lengthy reply, but I'm sure some folk will find it useful.