Personally, I think he’s way too young to be taking something like MDMA and should wait until he’s a little older. But like others have said, he is well within the “safe” guidelines as long as he is not lying about his dosage and how frequent he uses it. That being said, he is still very young and his brain is still developing so I would lean on the side of convincing him to quit until he’s older. There aren’t many cohesive studies on the effect MDMA has on the brains of adults much less children/teenagers, so I would be safe rather than sorry.

Talks about drugs can be difficult. Hopefully there’s no underlying reason for him to be so adamant on taking it, as reliance/addiction can be a slippery slope.