Calcitonin
Peptide Hormone / Bone Metabolism RegulatorapprovedAlso known as: Salmon Calcitonin, Calcitonin-Salmon, Miacalcin, Fortical, Calcimar
A 32-amino acid peptide hormone produced by thyroid C-cells that inhibits osteoclast activity and lowers blood calcium, used therapeutically for osteoporosis and hypercalcemia.
Overview
Calcitonin is a peptide hormone naturally produced by the parafollicular cells (C-cells) of the thyroid gland in response to elevated blood calcium levels. It counteracts parathyroid hormone (PTH) by inhibiting osteoclast-mediated bone resorption and increasing renal calcium excretion. Salmon calcitonin is 40-50 times more potent than human calcitonin and has been the basis for therapeutic formulations. It was historically used for postmenopausal osteoporosis and Paget's disease, available as nasal spray (Miacalcin/Fortical) and injection. However, its use has declined due to concerns about long-term cancer risk and the availability of more effective osteoporosis treatments (bisphosphonates, denosumab). It remains useful for acute hypercalcemia and bone pain from fractures or Paget's disease.
Mechanism of Action
Calcitonin acts through the calcitonin receptor (CTR): (1) Binds CTR on osteoclasts, directly inhibiting bone resorption within minutes; (2) Reduces osteoclast number through decreased recruitment and increased apoptosis; (3) Increases renal excretion of calcium, phosphate, sodium, and magnesium; (4) Provides analgesic effects in bone pain through central mechanisms (endorphin release, serotonin modulation); (5) May have protective effects on cartilage in osteoarthritis; (6) Effects are subject to tachyphylaxis — receptor downregulation reduces efficacy with continuous use.
Molecular Formula
C145H240N44O48S2
Molecular Weight
3431.88 g/mol (salmon calcitonin)
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 (salmon)
Dosage Protocols
Dose Range
200 IU – 200 IU
Frequency
Once daily
Route
intranasal
Cycle Length
Ongoing (with periodic reassessment)
One spray (200 IU) in alternating nostrils daily. Supplement with calcium and vitamin D. Consider more effective alternatives.
Source: FDA prescribing information
🧮 Personalized Dosage Calculator
💰 Estimated Pricing
Typical Supply
200 IU/spray nasal, 3.7mL
Last Updated
2026-02
FDA-approved (Miacalcin/Fortical). Generic nasal spray: $30-60. Injectable: $50-120. Used for osteoporosis.
⚠️ Prices are estimates based on publicly available data and may vary significantly by vendor, location, and prescription status. This is not medical or financial advice.
Side Effects
| Effect | Severity |
|---|---|
| Nasal irritation (spray) | mild |
| Nausea | mild |
| Flushing | mild |
| Cancer risk (long-term) | severe |
| Hypocalcemia | moderate |
Pros & Cons
Rapid onset bone resorption inhibition — useful for acute hypercalcemia
Analgesic effect for bone pain (vertebral fractures, Paget's disease)
Non-invasive nasal spray formulation for osteoporosis
Less effective than bisphosphonates and denosumab for osteoporosis
Tachyphylaxis — effects diminish with continuous use
Potential cancer risk signal with long-term use led to EMA restrictions
Research Studies
🩸 Blood Work
No specific bloodwork requirements reported for this peptide. General health panels are always recommended before starting any peptide protocol.
Legal Status
FDA-approved for postmenopausal osteoporosis, Paget's disease, and hypercalcemia. Available as nasal spray and injection. EMA recommended against long-term use due to cancer risk signal. Prescription-only.
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