Phenylmorpholines

Phenmetrazine and its relatives: the amphetamine amine closed into a morpholine ring, whose oxygen changes how the body handles the compound without stopping it releasing noradrenaline and dopamine. Phendimetrazine is a prodrug converted to phenmetrazine; 3-FPM is the fluorinated research-chemical member the family is best known for now; pseudophenmetrazine is the diastereomer and much weaker, which is the family's own reminder that stereochemistry decides activity here.

What varies most is duration, and it is long enough that people redose while the previous amount is still working — the pattern behind most of the harm reported in this family. Phenmetrazine was marketed as an appetite suppressant and left a substantial dependence record behind it. Cardiovascular strain, insomnia continuing well past the wanted effect, and compulsive redosing are the class harms.