Arg-Phe-NH2, HCl

RFamide (Arginylphenylalaninamide) is a neuropeptide that has contraction-inducing activity in gastropod muscles. Its contractile effect is additive with acetylcholine and is regulated by 5-hydroxytryptamine. It can also mobilize intracellular calcium to maintain tension.

[1] RFamide neuropeptide actions on molluscan proboscis smooth muscle: interactions with primary neurotransmitters