I am sceptical about 5-HTP. In my experience it does very little to me either as an antidepressant, sleeping aid or pre-loading agent (though haven't used it much in this capacity, so experience is very limited here). I would have thought that, as 5-HTP only has a 2-3 hour half life, the blocking of effect would only last perhaps 6-8 hours. A bigger issue you might have of course is the fact that aMT is an MAOI. I have seen aMT potentiate both Speed/MPA and MDMA massively, even dosing the second agent several hours after the first. In fact the Speed combination (and I wasn't feeling the speed massively) with aMT taken a few hours later was perhaps the most stimulated I've felt.
Going slightly off-topic here (sorry), but something thouart_that suggested (about the pharmacology of aMT - as an ADD type discussion), would be a pretty interesting discussion. An observation I have made about combining DOC with aMT (not at the same time, with a 5-6 hour gap) greatly increased my tolerance to DOC, and eliminated most of DOC's rather mindbending psychedelic effects (this is on insufflated doses of 7-8 mg, though administered over a few hours - that should have inverted my mind). This has made me wonder about aMT's mode of action. I wondered whether the aMT blocks the DOC from reaching the receptor site properly, or does aMT have a mild reuptake inhibition effect. Either way, its 5HT affinity must be quite strong if it can compete over DOC!!! I've also noticed that it can take a lot longer to come up on DOC whilst on aMT and the DOC body feeling isn't strong and takes several hours before it gets going. Very little of the body energy seems to be there.
On the other hand, the level of euphoria experienced from this combination is second to none (far, far stronger than aMT alone - surpassing MDMA, but for around 18 hours!) so something is obviously happening with the DOC. I have, however decided, that given how valuable DOC is, and how personally sought after are its psychedelic effects, that I won't be combining them again. Although the euphoria was incredible, I feel its a waste of DOC, particularly given its rather unique psychedelic properties (I nickname it the intellectual psychedelic as I always feel far more intelligent whilst on DOC, almost like my IQ is substantially increased, and experience vastly improved intellectual fluidity).