Cyclopentamine (trade names Clopane, Cyclonarol, Cyclosal, Cyklosan, Nazett, Sinos, among others) is a sympathomimetic and vasoconstrictor drug of the alkylamine family and related to the arylalkylamines.

Cyclopentamine was indicated in the past as an over-the-counter (OTC) medication for use as a nasal decongestant, notably in Europe and Australia, but has now been largely discontinued.

Cyclopentamine acts as a releasing agent of the catecholamine neurotransmitters norepinephrine (noradrenaline), epinephrine (adrenaline), and dopamine.

When ingested orally in sufficient quantities, cyclopentamine produces similar effects to amphetamine, methamphetamine, and propylhexedrine.

The difference between them is that whereas methamphetamine is an aromatic molecule containing a phenyl group, cyclopentamine and propylhexedrine are entirely aliphatic and contain no delocalized electrons at all.