What is 7-OH Mitragynine?

In recent years, kratom has become increasingly debated and more popular worldwide. But few people know that its strongest effects are not due solely to mitragynine, the main alkaloid of the plant Mitragyna speciosa. The main role is played by a substance called 7‑hydroxymitragynine, or 7‑OH mitragynine. Let’s take a closer look at it.

Where does 7‑OH come from?

What is important to mention is that 7‑OH is found in kratom leaves only in a very small amount. In some varieties, almost not at all. That might lead one to think it is not an important component. However, the opposite is true.

After consumption of kratom, the main alkaloid, i.e. mitragynine, is converted in the liver precisely into 7‑OH mitragynine. This process is carried out by enzymes, mainly CYP3A4, which commonly metabolize other substances in the body as well.

The resulting 7‑OH then penetrates the blood–brain barrier into the brain, where it binds to opioid receptors. And this is where its main effect begins.

Effects of 7‑hydroxymitragynine

7‑OH mitragynine is among the strongest alkaloids associated with the plant Mitragyna speciosa. It is formed naturally in the body after using kratom, but its effects are significantly stronger than the effects of mitragynine itself.

Possible benefits of 7‑OH

• Pain relief – very strong analgesic effects, sometimes compared to morphine
• Fast onset – the onset of effects is faster than with mitragynine itself
• Mood enhancement – can induce pleasant feelings, sometimes even euphoria
• Mental relaxation – relieves tension, stress, and can relax tense muscles
• Sleep support – at higher doses it may act sedatively

Why is it so strong?

Compared to mitragynine, 7‑OH has a multiple-fold higher potency. According to studies:

• it is up to 40× stronger than mitragynine itself
• it has higher affinity for µ-opioid receptors than morphine
• it can act at very low concentrations

At the same time it primarily activates G-protein signaling pathways, and does not activate β‑arrestin, which is associated with opioid side effects such as respiratory depression. Therefore it is believed it may have lower toxicity than classic opioids.

Risks? They are real

If 7‑OH is produced naturally in the body after consuming kratom leaves, the risk is relatively small. Another situation arises with concentrated products, such as:

• extracts with high 7‑OH content
• capsules and powders with synthetically made 7‑OH
• vaporizers and chewing candies with a “legal morphine” effect

These products may:

• induce strong euphoria
• lead to dependency and tolerance
• cause respiratory depression and sedation, similar to strong opioids

Comparison: Mitragynine vs. 7‑OH mitragynine

Are you interested in how regular mitragynine differs from its metabolite 7‑OH? Here is a clear comparison:

What do studies say?

• Kamble et al. (2020) – Scientific Reports (Nature): Confirmed that 7‑OH mitragynine is produced in the body from mitragynine and is the main substance responsible for its analgesic effects, because it effectively activates opioid receptors in the brain.

• Kruegel & Grundmann (2018) – Neuropharmacology / Drug Policy: This review shows that 7‑OH has a multiple‑times stronger effect than mitragynine, but also notes a lower risk of respiratory depression due to the different activation mechanism of opioid receptors.

• WHO Review (2021): The World Health Organization assessed 7‑OH as a substance deserving further research, but not yet considered so risky as to be internationally banned.

Safety and legal status

Thanks to the aforementioned review, we reach the question of legality. 7‑OH mitragynine is not currently classified as a controlled substance in the European Union. Although it is a potent alkaloid, it occurs only in trace amounts in kratom and is not commonly manufactured independently for commercial use.

In the USA, kratom has been repeatedly considered for prohibition, but ultimately it was not banned. The key factors are a responsible approach, informed use and appropriate dosing.

Conclusion

If you consume kratom and experience strong pain relief or relaxation, 7‑OH Mitragynine very likely plays a significant role. Even though it is present in the plant only in trace amounts, its effects are crucial. 7‑OH Mitragynine thus becomes a compound that should be known to all advanced kratom users.