Calcitonin
Also known as: salmon calcitonin, calcitonin-salmon, sCT, Miacalcin, Fortical, Calcimar, Cibacalcin, Ostora, thyrocalcitonin, human calcitonin, hCT, calcitonin nasal spray
Endogenous 32-amino acid peptide hormone; thyroid C-cell secretory product; antiresorptive bone agent; calcium-regulating hormone
What it is
Calcitonin is a hormone used in nasal sprays and injections to treat bone loss (osteoporosis) and bone pain in women after menopause. It works by slowing bone breakdown and can also reduce pain from spinal fractures. Injectable calcitonin is additionally used for Paget's disease and dangerously high calcium levels. Salmon calcitonin nasal spray (Miacalcin, Fortical) is FDA-approved for postmenopausal osteoporosis.
The scientific side
Calcitonin is described as a 32-amino acid peptide hormone secreted by parafollicular C-cells of the thyroid gland in response to elevated serum ionized calcium, with calcium-sensing receptor (CaSR) activation confirmed as the primary physiological regulator of calcitonin release in vivo (PMID 15099400). Its principal action is inhibition of osteoclast-mediated bone resorption: calcitonin binds to G-protein-coupled calcitonin receptors expressed on osteoclasts, suppressing their activity and reducing bone resorption rates, thereby decreasing serum calcium and urinary markers of bone turnover. This antiresorptive mechanism produces modest but measurable increases in lumbar spine bone mineral density in postmenopausal osteoporosis and reduces vertebral fracture risk. Calcitonin also acts on the kidney, promoting renal excretion of calcium, phosphate, sodium, and potassium, which contributes to its rapid lowering of hypercalcemia. A distinct and clinically relevant property is analgesia: multiple clinical trials and a systematic review of 14 double-blind studies confirmed calcitonin provides statistically significant pain relief in acute and chronic osteoporotic vertebral fractures (PMID 12659616), likely via central endorphin-mediated pathways and direct modulation of nociceptive neurotransmitters (PMID 39994161). In knee osteoarthritis, functional MRI evidence demonstrates calcitonin reverses abnormal hippocampal and tegmental nucleus activity patterns associated with chronic pain, confirming central neuromodulatory effects beyond bone (PMID 39994161). Calcitonin receptors are distributed across calcium-responsive tissues including kidney, bone, and brain (PMID 19078152). Salmon calcitonin is approximately 40-50 times more potent than human calcitonin at the human receptor due to structural differences that confer greater receptor affinity and longer half-life. The calcium-lowering effect in hypercalcemia is rapid in onset (hours) but often attenuates with continued use due to receptor downregulation ('escape phenomenon'), limiting long-term monotherapy for malignancy-associated hypercalcemia.
Class: Endogenous 32-amino acid peptide hormone; thyroid C-cell secretory product; antiresorptive bone agent; calcium-regulating hormone
Administration & storage
- Administration
- Intranasal spray: 200 IU per actuation into one nostrilalternating nostrils daily. Prime pump before first use (5–10 actuations until fine mist appears); re-prime if not used for 2+ days.Subcutaneous injection: preferred for self-administration; commonly used for Paget's disease and hypercalcemia. Sites: upper armthighabdomen; rotate.Intramuscular injection: used in clinical settings; volumes >2 mL should be injected into alternating sites.Intravenous infusion: used in severe hypercalcemia in hospital settings; not the standard route but documented in early clinical reports.
- Storage
- Unopened nasal spray bottles: store in refrigerator at 2–8°C (36–46°F). Once opened (pump activated): store at room temperature below 25°C (77°F) for up to 35 days (Miacalcin) or 30 days (Fortical); keep upright. Injectable solution: refrigerate at 2–8°C; do not freeze. Protect from light.
- Cautions
- Periodic urine sediment examination recommended with long-term injectable use; urine casts have been reported.,Reduce dose or use with caution in renal impairment; calcitonin is eliminated renally.,Nasal spray: inspect nasal mucosa periodically for ulceration or dryness; patients should alternate nostrils and report persistent rhinitis or epistaxis.,Test dose of 1 IU SC recommended before starting injectable calcitonin if allergy to salmon proteins is suspected; anaphylaxis, though rare, has been reported.,Nausea, flushing, and dizziness most common with injectable formulations — administering at bedtime or with food reduces severity.,Tachyphylaxis with hypercalcemia treatment: plan bisphosphonate combination therapy from initiation to manage escape.,Long-term use: discuss malignancy signal with patients and review benefit-risk balance annually (see known_safety_signals).
Legal & regulatory status
Salmon calcitonin nasal spray (Miacalcin 200 IU/actuation; Fortical 200 IU/actuation) is FDA-approved for treatment of postmenopausal osteoporosis in women more than 5 years post-menopause. Injectable salmon calcitonin…
Calcitonin is not listed on the current WADA Prohibited List. It is a peptide hormone used therapeutically for bone disease and calcium dysregulation and has no established performance-enhancing application in sport.…
Salmon calcitonin nasal spray is approved in Canada for treatment of postmenopausal osteoporosis (marketed as Miacalcin NS). Injectable calcitonin is also available with indications for Paget's disease and…
What it's studied for
- Postmenopausal osteoporosis — vertebral fracture prevention and bone density Phase III RCT / FDA-approved indication
- Acute and chronic pain from osteoporotic vertebral fractures — analgesic effect Human RCT / Systematic review
- Paget's disease of bone — suppression of abnormal bone turnover Clinical use / FDA-approved indication (injectable)
- Hypercalcemia — acute management Clinical use / FDA-approved indication (injectable)
- Knee osteoarthritis — pain neuromodulation Preclinical / early human study
- Chronic kidney disease-related bone disease — investigational Preclinical (Animal)
Safety signals
- Potential increased risk of malignancy with long-term use — FDA 2013 safety communication
- Hypocalcemia
- Nausea, flushing, and gastrointestinal symptoms (injectable formulation)
- Tachyphylaxis / escape phenomenon (hypercalcemia treatment)
- Hypersensitivity reactions including anaphylaxis (injectable; salmon protein allergy)
- Nasal mucosal irritation and epistaxis (intranasal formulation)
Contraindications
About these dose ranges
Dose ranges below reflect commonly reported community protocols. Where published research cites a specific dose, the PMID is linked. Doses without citations are not clinical recommendations — they reflect what practitioners and researchers commonly report using.
Community-reported dosing
| Route | Dose | Frequency / Duration | Population / context | Source tier |
|---|---|---|---|---|
| Unspecified | 200 IU per actuation | — | Postmenopausal women — osteoporosis (intranasal) | Research |
| Unspecified | 100 IU subcutaneous or intramuscular | — | Paget's disease of bone (injectable) | Research |
| Unspecified | 4 IU/kg subcutaneous or intramuscular every 12 hours | — | Hypercalcemia (injectable) | Research |
| Unspecified | 200 IU intranasal daily or 100–200 IU injectable daily | — | Acute vertebral fracture pain (intranasal or injectable) | Research |
| Unspecified | 200 IU intranasal daily | — | Transient osteoporosis / acute orthopaedic pain (intranasal) | Research |
| intranasal | 200 IU salmon calcitonin nasal spray | once daily, alternating nostrils | postmenopausal women with established osteoporosis (more than 5 years post-menopause) |