Calcitonin salmon (also known as salcatonin) is a synthetic 32-amino-acid peptide (MW ~3431.9 g/mol) identical to calcitonin produced by the ultimobranchial glands of salmon. It is approximately 40-50 times more potent than human calcitonin in inhibiting osteoclast-mediated bone resorption. It is FDA-approved as a nasal spray (Miacalcin, Fortical) for postmenopausal osteoporosis, and as an injection for Paget disease of bone, hypercalcemia of malignancy, and osteoporosis. Calcitonin salmon is now considered a second- or third-line osteoporosis therapy due to modest efficacy compared to newer agents.
Category: Bone / Calcitonin. Evidence rating: A (strong human clinical data).
Clinical status: FDA-approved (Miacalcin nasal spray and injection; Fortical nasal spray)
Calcitonin salmon binds to the calcitonin receptor (CTR), a G-protein-coupled receptor on osteoclasts, rapidly inhibiting osteoclast-mediated bone resorption. It causes osteoclast contraction, detachment from bone surfaces, and reduces osteoclast number. In addition to its anti-resorptive effects,…
Safety considerations: Nasal spray: rhinitis (12%), nasal symptoms (epistaxis, dryness, crusting), headache, back pain; Injection: nausea (10%), facial flushing (2-5%), injection site inflammation, local pain; Allergic reactions: calcitonin is a peptide; skin testing may be considered before injection in patients with suspected salmon protein sensitivity.
Reviewed by the PeptideAtlas Editorial Team.
| Amino-acid sequence | Cys-Ser-Asn-Leu-Ser-Thr-Cys-Val-Leu-Gly-Lys-Leu-Ser-Gln-Glu-Leu-His-Lys-Leu-Gln-Thr-Tyr-Pro-Arg-Thr-Asn-Thr-Gly-Ser-Gly-Thr-Pro-NH2 (disulfide bridge Cys1-Cys7) |
|---|---|
| Molecular weight | ~3431.9 g/mol |
| CAS number | 47931-85-1 |
| Half-life | ~43 minutes (injection); effective duration 8-24 hours |
| Bioavailability | ~3-5% (nasal spray); ~66-71% (SC/IM injection) |
| Production method | synthetic |
| Anti-doping status | not-listed |
| US regulatory status | FDA-approved. Miacalcin nasal spray (200 IU/dose) and injection (200 IU/mL) approved. Fortical nasal spray (recombinant) approved. Considered second/third-line osteoporosis therapy. |
In 2012, the EMA conducted a review that identified a small but statistically significant increased risk of cancer (particularly prostate cancer) with long-term calcitonin use in pooled clinical trial data. The EMA concluded that the cancer risk outweighed the modest osteoporosis benefit of the nasal spray, leading to withdrawal of intranasal formulations in the EU. Injectable calcitonin was…
Calcitonin salmon is now considered a second- or third-line therapy for osteoporosis. Bisphosphonates, denosumab, and anabolic agents (teriparatide, abaloparatide, romosozumab) all provide superior fracture risk reduction. Calcitonin may still have a role for patients who cannot tolerate other therapies or for its analgesic properties in acute vertebral compression fractures.
With continuous use, calcitonin can lose its effectiveness within 48-72 hours (tachyphylaxis). This is particularly problematic when using calcitonin for hypercalcemia. The mechanism involves downregulation of calcitonin receptors on osteoclasts. For hypercalcemia, calcitonin is used as a bridge therapy while waiting for bisphosphonates to take effect, not as a long-term calcium-lowering agent.