They are equally legal in the US (Schedule II). Label will usually say something like "Methamphetamine, generic for Desoxyn." It is, however, much harder to find a doctor that will give you a prescription as compared to other stimulants, and some pharmacies will refuse to fill it.
Believe it or not, marijuana (since 2018 only strains containing significant levels of delta-9 THC) is illegal in the US in almost all circumstances, but methamphetamine is legal with a prescription.
I mean, yeah. Their point is that the substances are extremely chemically similar to the point where they can be treated as different intensities of the same drug.
Yeah that is what I was getting at in my first reply. Amphetamine is a party drug, meth is what junkies on the street use. The guy I responded to said meth, which carries a lot more stigma, and together with all the other negatively charged statements he made is just abhorrent, basically calling her a junkie that deserved to die.