The question of kratom’s half life is a bit more complex than one might think. The reason for this is the large amounts of enzymatic and brain interplay between several alkaloids, which all have quite varied half-lives.
Because of the differences among alkaloid half lives, the duration of kratom can very quite dramatically from strain strain to strain and from plant to plant. For this reason, I will analyze both the half-lives of the prominent alkaloids as well as the kratom duration differences between strains to give you a better idea of what to expect from each strain.
Although there are 24 identified alkaloids in kratom, as well as many still to be identified, only two of these alkaloids do we have a decent understanding of their half lives. Luckily, these two alkaloids to a large portion of the heavy lifting when it comes to the effects of kratom. These two alkaloids are 7-hydroxymitragynine and mitragynine. However, because of the slower digestion of plant material, note that kratom half-life alkaloids do not completely describe the duration of its effects.
Mitragynine is the most prominent alkaloid found in kratom, and is thought to be responsible for a large portion of kratom’s stimulating effects, as well as some painkilling effects. From research, we know that the standard half life of mitragynine is 23.24 ± 16.07 hrs , depending upon the individuals natural levels of enzymes and other factors. This means that on average 23.24 hours from the moment of absorption, half of the alkaloid is still in one’s body.
This alkaloid is by far the most potent painkilling alkaloid found in kratom, despite being only available in minute quantities within the leaf. Interestingly, despite similar structure to mitragynine, has quite a bit shorter duration. While the research has varied, it seems to point to an average half life of 2.5 ± .7 hrs . The shorter half-life of this alkaloid describes why some of those who suffer from pain prefer smaller doses more frequently throughout the day, to maintain a constant level of 7-hyroxymitragynine.
As you may have noticed, different strains can provide radically different durations of effect. The reasons for this vary, but the primary reasons are:
All three of these contribute to kratom duration, however, for this comparison between vein types and duration, it is assumed that the grind density is the same.
Red vein kratom is by far the most commonly purchased variety because of its pronounced painkilling and mood boosting effects. As far as kratom duration, red vein strains last fairly long — typically around 4.5 to 6 hours with an average grind. Because of the long duration and high 7-hydroxymitragynine content, it is the most commonly used by those looking for substantial pain relief.
Green vein strains are quite interesting, and can be the longest lasting variety of kratom. There are a few suspected reasons for this: cell wall density (which many green malaysian strains are a prime example of), and high mitragynine content. However, they may be more be other factors that contribute to its long duration. While not every green vein is extremely long lasting, some can last an impressive 8 hours.
White vein strains, while quite energizing, are one of the shortest lasting strains — typically only around a four hour duration. It is important to note, however, that some rare white vein strains can last quite a bit longer. Like the green vein, we are not entirely sure why this kratom duration is as different as it is.
Kratom half-life and duration are very tricky concepts, especially due to the lack of research available on these topics. Hopefully within the next few years, we will have enough compiled research to fully understand this unique plant.