Salmon Calcitonin

Bone / Osteoporosis

Also known as: sCT, Miacalcin, Fortical, Calcimar, Calcitonin-Salmon

Calcitonin FamilyResearch phase: FDA-approvedRegulatory: FDA-approved for postmenopausal osteoporosis (nasal spray, injection) and Paget disease. EMA recommended restricting use due to cancer signal in long-term studies.

Mechanism

Salmon calcitonin is a 32-amino-acid peptide used to treat osteoporosis and Paget's disease of bone. The salmon form is 40-50 times more potent than human calcitonin because of its greater receptor binding affinity. It works by directly inhibiting osteoclasts (bone-resorbing cells), slowing bone loss. Available as a nasal spray (Miacalcin, Fortical) or injection, it also has analgesic effects for bone pain.

Technical detail

Salmon calcitonin (sCT) is a 32-amino-acid peptide with a disulfide-bridged N-terminal ring, differing from human calcitonin at 16 positions. These substitutions confer higher CTR binding affinity and resistance to degradation, resulting in 40-50x greater potency. It activates the calcitonin receptor (CTR, Gs-coupled) on osteoclasts, increasing cAMP-PKA signaling which disrupts the osteoclast ruffled border, inhibits carbonic anhydrase II and cathepsin K, and induces osteoclast quiescence. Net effect is reduced bone resorption. Analgesic properties may involve central serotonergic mechanisms and beta-endorphin release. Nasal bioavailability is approximately 3-5%.

Evidence