I realise it's convenient for some kratom supporters to claim otherwise, but I am also a kratom supporter and believe this kind of obvious misinformation harms, rather than furthers the cause.

> Opioids are substances that act on opioid receptors[1]

From your link[2]:

> The two main chemicals, mitragynine and 7-hydroxymitragynine, have strong activity at the main opioid receptor, the “mu” receptor, which is the same one stimulated by heroin and oxycodone.

It's not an opiate, which is just the subset of opioids derived from the opium poppy. But neither are many pharmaceutical opioids.

[1]: https://en.wikipedia.org/wiki/Opioid

[2]: https://www.health.harvard.edu/blog/kratom-fear-worthy-folia...