• Mitragyna speciosa Kratom: a sedative-narcotic and a stimulant

    The dual nature of Mitragyna speciosa Kratom’s effects places it in a category of its own, and the common pharmacological classification of Kratom as a “non-opioid narcotic” does not accurately reflect this particularity.

    The main psychoactive effects of Kratom are indeed opioid like, somewhat similar and related to the sedative and narcotic effects of opiates or other opioids. However Mitragyna speciosa Kratom is also rather unique in that its chemical makeup and mode of action (see “Pharmacology and Mode of action of Mitragyna speciosa Kratom”) also induces effects somewhat comparable to those of stimulant plants such as Yohimbe, with which Kratom shares pharmacological properties.

    This stimulant effect is a major difference between Mitragyna speciosaKratom and opioids.
    Indeed, if some opioids, mostly thebaine derivatives such as hydrocodone or oxycodone, do have a slight stimulant effect, in the sense that they can cause insomnia, Kratom, at stimulant doses actually produces a real psycho-physiological stimulation, giving the one a lasting focused energy, increase in stamina, which can be used in social situations, for creativity and productivity increase and physical exercise.

    Mitragyna speciosa Kratom also combines this with an anti-oxidant / immunostimulant action somewhat similar to another chemically related plant, Uncaria tomentosa (cat’s claw / uña de gato).
    Kratom effects are clearly connected to opioid receptor activity, with the opiate-like effects appearing to be mediated mostly by delta and mu opioid receptors.

    The length of Mitragyna speciosa Kratom’s psychoactive effects range from short lived to moderate, depending on multiple factors such as the Kratom’s quality, dose, method of intake and one’s metabolism. In general, Mitragyna speciosa Kratom effects come on within 10 to 20 minutes and continue to build for up to an hour after consumption last 2 to 6 hours or more, especially with extracts, which are usually felt more progressively and for longer periods of time. Some users report stimulant or sedative effects lingering for a few hours more.

    The nature of these effects is very much related to the dosage taken: a low to moderate Kratom dose will usually (but not always) be actually quite stimulating, while a high Kratom dose is almost always be quite sedating.

    In its original South-East Asian socio-cultural setting, Kratom has a history of traditional use both as a relaxant and as a stimulant, fresh Mitragyna Speciosa leaves being commonly chewed to help with physical labour, diminishing fatigue, pain, hunger and monotony, which could be compared to similar uses of Betel-nut ( Areca catechu ) or Coca leaves chewing. This mode of intake and regularity of use seems to bring out Mitragyna speciosa Kratom’s stimulant effects, rather than the relaxing ones.

    The Mitragyna speciosa plant contains many alkaloids, yet the main activity is thought to come from the mitragynine, mitraphylline and 7-hydroxymitragynine alkaloids. These alkaloids are structurally related to psychedelics yet induce dose related stimulant and opioid like effects.

    Historically, mitragynine was first held to be responsible for the plant’s opiate like narcotic effects. More recent studies, however, have shown that 7-hydroxymitragynine has powerful analgesic effects and some opioid agonistic properties, making it a more likely candidate as Mitragyna speciosa ’s main active alkaloids. Yet a total of 25 alkaloids ( see “Pharmacology of Mitragyna speciosa Kratom” for more details ) have been identified in the Mitragyna speciosa plant, and their combined effects on humans are still relatively unknown or unresearched.


    It is clear that the nature of the Mitragyna speciosa plant’s complex alkaloid makeup and the synergy of this complex alkaloid makeup are responsible for Kratom’s complex mechanism combining stimulant and sedative effects.

    As with all psychoactive substances, effects of Mitragyna speciosa Kratom can vary greatly from person to person. Which type of Kratom effect, mostly stimulant or sedative, predominates depends both on the level of the substance in one’s blood, which is related to dose and
    intake method, as well as on individual metabolic, psychological and physiological differences between users.


    The stimulant and sedative effects of Mitragyna speciosaKratom work hand in hand, yet a tolerance develops more quickly to the opiate-like effect, which induces an increased stimulation over time, even with lower doses.

    Even though Mitragyna speciosaKratom works like opiates and opioids, partially binding to the brain’s μ opioid receptors, it actually shares some similarities with the actions of yohimbine and other tryptamines, the type of monoamine alkaloids found in many hallucinogenic plants and complex psychoactive compounds- yet Mitragyna speciosaKratom does not have real psychedelic effects.

    From a physical point of view, the most common effects of Mitragyna speciosaKratom, especially in higher doses, are similar to those of opiates: constriction of pupils, which look smaller, an increase in blood pressure and heart rate, hunger suppression, constipation, analgesia / pain relief and respiratory depression comparable to that of codeine, cough suppression, a slight vasodilator muscle relaxant effect, and a feeling of bodily warmth, increased body heat and sweating. Yet unlike opioids,



    Depending on the Kratom dose, method of intake and also one’s metabolic response, itching, nausea and hangovers can occur, similar to those of opiates, yet Kratom does not seem to induce the systematic vomiting associated with opiate use.

    Psycho-physiological Kratom effects are more complex and also very much dose related. They usually include stimulation, increased sociability and talkativeness, euphoria, stress decrease, peaceful relaxation and well-being, sleepiness and sedation. Effects on sleep also vary, Kratom can help induce sleep but also induce a form of insomnia, including a state somewhat similar to the “waking dream” of opiates.

    Most reports of Kratom use are positive, highlighting the euphoric, pleasurable nature of Mitragyna speciosaKratom. Kratom’s sedation is more akin to a clear headed, alert relaxation, with gradually fading of effects, a smooth transition back to baseline consciousness, no crash of any sort.

    While Mitragyna speciosa Kratom clearly has a potential to develop a physical and/or psychological addiction issues through overuse, in general Kratom does not seem to lead to the kind of unmanageable, compulsive use that opiates and opioids can bring- and not as many side effects.

    Moderate users feel generally healthy, and good indication, reinforced by Kratom’s complex pharmacology that an occasional, moderate use of Mitragyna speciosaKratom is not only quite safe but potentially beneficial to the user.

    Virtually all negative reports involving Kratom seem to involve either large doses, a frequent, almost addictive over-use and multi-drug combinations…


    Mitragyna speciosaKratom is a potent plant, with many beneficial aspects, yet which should also be used responsibly, with moderation.