Andrew Huberman· PhD
So nowadays, some of the companies that sell kratom. And by the way, this is sold over the counter as a supplement. It does not require a prescription to purchase, at least at this point in time, in the United States. Some of these products will have a higher concentration of one or the other alkaloids within them such that you can't really compare one gram of one brand of kratom to one gram of another brand of kratom because they can have wildly different levels of these different alkaloids.