I think that is no problem. The main impurity should be Arzure-B, but that is the main metabolite in your body anyway.
(By the way Azure-B itself is an even more potent MAO-A Inibitor, I tink around 5 times as potent as MB itself)
Then there is Aluminium, Chrome, Ferrus ect. My stuff is 99.9% and the amounts of toxic metals are way below the
amounts in sea fish, so even with 99%, that's better then nature I think.
They have to write "not for human consumption" ect, for legal issues. There are completely other taxes, safety measures
and claims for damages, if something is declared as for human consumption.
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But be careful with the 10mg. I know people here see it different, but IMHO MB is a very potent MAO-A inibitor. However it is reversible and that effect only last a few hours. I take 1mg occasionally with some DXM and it potentiate the serotonin effect already very noticeable, despite of the NMDA effect, which shifts the overall experience. But since its action on MAO-B is small, I think you don't have to be careful with tyramine.
I think a good deal of people here, who say they "can feel" MB, secretly describe its MAO-A effect. Especially if they say, the feeling only last a short amount of time. The mitochondrial part is not a feeling, IMHO.
Anyway, if you are after that mitochondrial effect, then I would say 10mg is way to much, because the amount of MB in your system is criticial for this effect. To much and it is gone. I think 10mg is more in the range of the tau-protein effect, like on the low end of the Rember studdy.
Would start with 0.5mg. Of course there is no drug-effect or something. If I want to feel its power, I have a very hard body exercise, like running and after that I can still do brain work - clear headed.. MB is good in combination with sport. I spend years of my life as a couchpotato, because every time I tried healthy exercise, I ended up with brain fog, which get in the way of my job as a mathematician. MB changed that in no time and now I can do extensive exercise of all kind, without a reduction in my mental abilities.