I have been thinking about mixing Kratom (or maybe a full spectrum kratom extract) with cinnamon oil, so the cinnamaldehyde binds to the mitragynine and 7-hydroxy-mitragynine and alters its molecular structure. Doing this to other molecules like LSA, caffeine, and hordenine has made them more potent and more lipophilic. They will enter the brain from the blood more this way, but sometimes there effects are unpredictably altered.
Phenethylamine when combined with cinnamon oil seemed to produce toxic effects, but I am not 100% sure about this, it's possible that it was made much more potent and the dose tested was actually an overdose, or that something else was at play. Hopefully I can test this sometime in the future.
However, a number of compounds and herbs are made better by reacting them with cinnamon oil. LSA, caffeine, cayenne pepper (capsaicin), and hordenine are altered to produce different, but somewhat more applicable analogs. LSA and caffeine are made 3 times more potent this way. Caffeine + cinnamon oil lasts much longer than caffeine. LSA is made into "LSC" which is much more euphoric, vasodilating (as opposed to LSA's painful vasoconstriction) and more stimulating than LSA. Hordenine when combined with cinnamon oil loses its MAO-B inhibiting properties but becomes much more stimulating (probably from increased BBB crossing). Cayenne pepper, when combined with cinnamon, becomes much more stimulating and lasts much longer.
So, cinnamon oil seems designed to enhance the effects of many herbs and compounds, but not all of them. Since it's usually a bad idea to add any functional groups to the indole nitrogen atom of tryptamines like DMT and psilocin, and mitragynine has a DMT backbone (and the indole nitrogen is the only place cinnamon oil could bind to mitragynine), adding cinnamon oil to kratom might make the mitragynine or other compounds completely inactive (or worse, toxic). I have prepared a batch, and a friend asked if he could have it to test later. He hasn't tested it yet but once he does I will post what happens.
It would be very useful if we could prepare highly potent extracts, on the order of milligram potency!
Also, if this works it would probably make kratom much more addictive. I still recommend combining this with cats claw extracts to reduce addictive potential. Something I'd really like to try is combining cats claw with cinnamon oil to make it more potent. Imagine getting it down to an active dose at 30 mg! Theoretically we could try this method with all herbs containing an exposed nitrogen atom (bonds still available), even kanna (but I wouldn't try this, because it would produce way too much serotonin). But we don't even know if cats claw becomes more toxic when combined with cinnamon oil, so we have to start at extremely low doses before we test any of this.
It doesn't take a lot of cinnamon oil to completely react. They have to react outside of the body (as opposed to ingesting them separately and letting them react inside the body, that doesn't work). You just need enough to get it wet throughout, and it should react pretty quickly.
I stress, if you attempt to do this start with very low doses, because the molecules could become toxic. We would only consider trying this because many compounds seem to be improved in some way when combined with cinnamon oil, so it stands to reason other compounds might be improved as well. But some could become toxic, so please don't do anything stupid like taking a whole gram of kratom with cinnamon oil without testing it first! Nobody has any experience with kratom + cinnamon oil yet, but hopefully soon we can see whether or not it helps.