My gym mate keeps wondering how different methamphetamine and amphetamine really are when it comes to serotonin

My gym mate has been reading about stimulants lately and got stuck on one particular question. He keeps seeing people say that methamphetamine is more serotonergic than amphetamine, but nobody seems to explain whether that difference is minor, noticeable, or something that completely changes the experience.

What he’s trying to understand is whether the gap is large enough to matter at lower doses, or if it only becomes relevant as doses increase. A lot of discussions throw around terms like dopamine, noradrenaline, and serotonin, but rarely connect them to what a person would actually notice.

He’s also curious about how much of methamphetamine’s reputation comes from that serotonergic component versus everything else going on pharmacologically. Some people make it sound like a completely different category of experience, while others describe it as more of a spectrum.

The more he reads, the more the conversation seems to split between technical explanations and personal anecdotes, which makes it hard for him to gauge what is actually significant and what is just internet lore.

Has anyone else gone down this rabbit hole and tried to understand the practical difference between the two? Did the serotonin angle end up seeming important, or was it overshadowed by other factors when comparing them?