The reason for the difference in effects from strain to strain is the variability of kratom’s alkaloids; in fact, there are over 28 identified alkaloids found within the plant with different half-lives and durations. For more information on these alkaloids, their effects, and their content (% of total alkaloid weight, one standard deviation), refer below:

• 7-hydroxymitragynine – Analgesic/painkiller (opioid receptor agonist), antidiarrheal, antitussive – 1.5 – 2.5%
• Mitragynine – Analgesic/painkiller (opioid receptor agonist), antidiarrheal, antitussive, adrenergic receptor agonist (mild stimulant), antimalarial – 40 – 75% [Lowest recorded content: 12%]
• Speciogynine – Smooth Muscle Relaxer – 6.5 – 7.2%
• Mitraphylline – Muscle relaxer, vasodilator, anti-hypertensive, anti-amnesic, immune system stimulant, anti-leukemic – less than 1%
• Epicatechin (EGC) – Antioxidant, antiviral, anti-mutagenic, anti-leukemic, anti-inflammatory, anti-diabetic. Commonly found in green tea. – 1%
• 9-Hydroxycorynantheidine – Painkiller/analgesic – 1%
• Corynantheidine – Mu opioid Antagonist – less than 1%
• Isomitraphylline – Immune System Stimulant – less than 1%
• Isomitrafoline – Immune System Stimulant – less than 1%
• Isorhynchophylline – Immune System Stimulant – less than 1%
• Isopteropodine – Immune System Stimulant – less than 1%
• Ciliaphylline – Analgesic, antitussive – less than 1%
• Corynoxine A – Dopamine Mediator – less than 1%
• Corynoxine B – Dopamine Mediator – less than 1%
• Ajmalicine – Sedative (Anti-Adrenergic), increase blood flow to brain, smooth muscle relaxer – less than 1%
• Rhynchophylline – Anti-inflammatory, vasodilator, anti-hypertensive – less than 1%
• Speciociliatine – Mild opioid receptor agonist – less than 1%
• Speciophylline – Anti-leukemic – less than 1%
• Tetrahydroalstonine – Anti-adrenergic, lowers blood sugar – less than 1%
• Akuammigine – Inactive – less than 1%
• Mitrafoline – Inactive – less than 1%
• Mitraversine – Inactive – less than 1%
• Speciofoline – Inactive – less than 1%
• Stipulatine – Inactive – less than 1%

Known kratom researchers such as Takayama H, Shellard EJ, Raymond-Hamet, Becket AH, Philipson JD and Lee CM, have shown that the alkaloid profiles of the plants from different regions vary heavily; especially in Thai strains, in which case mitragynine content is well above the average. Malaysian strains, on the other hand, have proportionally low levels of mitragynine, suggesting its potency is due to proportionally higher levels of 7-hydroxymitragynine.

These differences in alkaloid profile are what make each strain unique and effective in quite different ways, but there is still much research to be done until we have a complete understanding of alkaloid effects, and an alkaloid profile of each strain, region, and vein color.