Mitragynine was once thought to be Mitragyna speciosa Kratom’s main active ingredient, yet more recently it has been found that the main active constituent is in fact more likely to be the potent 7-hydroxy derivative of mitragynine: 7-hydroxymitragynine
First mentioned in a 1994 study paper, 7-hydroxymitragynine is another indole, with the molecular formula C23H30N2O5. While present in the Kratom plant in much smaller quantities than mitragynine (2% of the total alkaloid content in Kratom leaf) it has much more potent μ-opioid agonist properties, as well as profound analgesic effects.
Nearly all the chemical studies of Mitragyna speciosa Kratom prior to the late 1990’s were done on mitragynine or crude plant material, with the given assumption that mitragynine was the most important alkaloid. With 7-hydroxymitragynine now clearly standing out as the main psychoactive alkaloid in Mitragyna speciosa Kratom, a lot of these studies need to be revised.
Studies involving rats have suggested that 7-hydroxymitragynine has strong opiate agonistic effect, and is significantly more effective, in terms of dosage weight, than the analgesic effects than morphine.
This notion of dosage activity per weight has apparently created confusion in prospective users, giving birth to quite fantastic statements and speculations on 7-hydroxymitragynine’s potential potency. A statement often seen is that 7-hydroxymitragynine is “13x the potency of morphine”, a figure which came from the Matsumoto et al. study (2004. Life Science, 74:2143-55), comparing the effects of the two substances on guinea-pig intestine (ileum).
However, when the actual analgesic effects of morphine and 7-hydroxymitragynine were compared, 7-hydroxymitragynine was found to be only 6x as potent as morphine, when both substances were given orally, and 2x as potent when administered subcutaneously. And in terms of effects, just because a substance is more active by weight does not mean that it will be more pleasurable (than morphine) or get one “higher”...remark that has been confirmed by the results of subsequent experimentation with this alkaloid.
Yet 7-hydroxymitragynine’s analgesic potency is really interesting for medical applications such as pain management, providing a potentially less addictive more effective alternative to available pharmaceuticals such as synthetic opiates. 7-hydroxymitragynine also appears to be absorbed orally better than morphine.
Though present in lower concentrations than other alkaloids, it is more than likely that 7-hydroxymitragynine plays a very significant role in the definition of Kratom’s effects. Bio-assays and experimentation seem to point out that 7-hydroxymitragynine acts strongly on μ opioid receptors (hinted by euphoria, respiratory depression, analgesia, and potential nausea) and maybe also sigma opioid receptors (hinted by cardiac stimulation, visual distortion).
A medical study has also focused on the involvement of μ-opioid receptors in antinociception and inhibition of gastrointestinal transit induced by 7-hydroxymitragynine.
Like Mitragynine, tinctures of 7-hydroxymitragynine (often shortened as 7OHM) high purity isolated alkaloid dissolved in ethanol, were made commercially available, and some experimenting has been done, though the purity and precision of the manufacturing process used (which requires advanced laboratory equipment and procedures such as column chromatography) is always a question in such cases.
7-hydroxymitragynine apparently cannot be made into a hydrochloride salt, and is sold as a freebase dissolved in ethanol. Contrarily to mitragynine, 7-hydroxymitragynine can be vaporised efficiently.
7-hydroxymitragynine can be taken orally, vaporised but is apparently more effective insufflated, after drying out the tincture on a plate. Some users have noted slight stomach discomfort when experimenting with this compound, even in medium doses.
For the pure alkaloid, reports state that a dosage of 1-3mg has a rather light "opiate-like" effects, mild, hardly noticeable for some.
A 4-5mg dosage induces effects quite similar to a low dose of pain killers, but nothing like morphine or opiates like hydrocodone or oxycodone, with a warm rushing sensation, but much more lucid, clear headed than opiates. The substance apparently has a strong aphrodisiac element to it. The effects peaked roughly 15 to 30 minutes after ingestion, declining in effectiveness by 50% around the 90 minute mark.
Some users reported nausea. After the experience, a feeling of sleepiness, apathy and slight depression a little like the after effects of opiates. Some users have noted combined lethargy and agitation on the second day after the experience, which is interestingly somewhat reminiscent of akathisia, one of the noted side-effects of stopping Kratom after a long period of intense use.
Other users have experimented with higher oral dosages, which have proved to be quite psychoactive, with a 7mg dose giving a clean cerebral high, with no anxiety. The come-up can be quite strong, then leading to deep thoughts and a euphoric daydreaming like feeling (not unlike high T.H.C. content cannabis).
The experience is said to induce some euphoria, but not as strong as full opiate agonists, more of a mood elevation. There is also a slight dissociation, strong physical sedation and analgesia, feeling one’s body very numb and distant.
Comparatively, users have noted that 7-hydroxymitragynine induces a surprising mental clarity/cognitive ability in comparison to the high level of physical sedation/analgesia. A few users have also noted visual distortion such as swelling of objects, changing of range, colour enhancement, a little like a low dose of psilocybin mushrooms.
Higher doses (i.e. up to 15mg) might prove to be even more psychoactive and slightly psychedelic, with increased visual distortion, but also an increase in the depressant aspect of the experience. Users have noted definite euphoria, as well as extreme analgesic effects, body numbness. Psychomotor faculties were strongly affected, movements and balance becoming, while thinking seemed to remain clear and lucid. Mild respiratory depression was noted, as well as strong cardiac stimulation (to a degree uncharacteristic of other opiates).
One must keep in mind that the effects of high doses of 7-hydroxymitragynine are not entirely known or understood, so it is best to work one’s way up gradually, with caution. Repeated small doses is also apparently the most pleasurable way to experiment with this compound, resulting in a much more pronounced euphoric rush, which continues throughout the dosing phase and doesn’t begin to dissipate until an hour or two after the last dose.
Most reports state that the commercially available 7-hydroxymitragynine tinctures were weaker than expected, comparatively expensive and generally much less pleasant than the effects of Mitragyna speciosa Kratom leaves or resin.
In conclusion, experiences with extracted active alkaloids such as mitragynine, 7-hydroxymitragynine and others all seem to point out that the experience is actually less enjoyable than a dose of full alkaloid spectrum Mitragyna speciosa Kratom leaves. And if one compares the doses of extracted alkaloids taken with their equivalent in full-spectrum Mitragyna speciosa Kratom, effects are also proportionally much weaker. A user even pushed things by I.V. injecting a combination of the commercially available Mitragyna speciosa Kratom alkaloid extracts, which is really not recommended and seen as potentially dangerous and life threatening. While the effects were strong, they were nowhere as potent as what a similar full-spectrum dose would have been (the experience also induced no “rush” like feeling).
All this points to the fact that there is a complex synergy and balance between the different alkaloids of full-spectrum Mitragyna speciosa Kratom leaf products, probably linked to antagonistic/synergetic properties of some alkaloids, and playing an important role in the nature and strength of Mitragyna speciosa Kratom’s psychoactive effects.