Question 1

What is Calcitonin?

Accepted Answer

Calcitonin is a 32-amino acid peptide hormone produced by parafollicular C-cells of the thyroid gland that inhibits osteoclast-mediated bone resorption. Salmon calcitonin (sCT), which has 40-50 times greater potency than human calcitonin, is the therapeutic form approved for osteoporosis and Paget's disease. Available as nasal spray (Miacalcin/Fortical) and injection, calcitonin directly reduces bone breakdown, provides analgesic effects for bone pain, and helps maintain calcium homeostasis. While largely superseded by bisphosphonates and denosumab for osteoporosis, calcitonin retains a role for acute vertebral fracture pain management.

Question 2

How does Calcitonin work?

Accepted Answer

Calcitonin binds to the calcitonin receptor (CTR, a class B GPCR) on osteoclasts, activating both Gs (cAMP) and Gq (calcium) signaling. cAMP elevation inhibits osteoclast ruffled border formation and acid secretion, rapidly reducing bone resorption. It also causes osteoclast retraction from bone surfaces and promotes apoptosis. Analgesic effects may be mediated through central serotonergic and β-endorphin pathways. In kidneys, calcitonin increases calcium and phosphate excretion.

Question 3

What are the research applications of Calcitonin?

Accepted Answer

Osteoporosis (Approved)

FDA-approved for postmenopausal osteoporosis. Reduces vertebral fracture risk by 33%. Nasal spray (200 IU/day) is the most common route.

Paget's Disease (Approved)

Reduces bone turnover and pain.

Acute Vertebral Fracture Pain

Provides analgesic benefit within days, useful for acute fracture pain management.

Hypercalcemia (Approved)

Acute treatment of hypercalcemia of malignancy.

Question 4

What are the biological pathways affected by Calcitonin?

Accepted Answer

CTR/cAMP/PKA in osteoclasts for resorption inhibition. CTR/Gq/calcium for osteoclast retraction. Central serotonergic and endorphin pathways for analgesia. Renal tubular calcium/phosphate handling.

Question 5

What are the potential side effects of Calcitonin?

Accepted Answer

Nasal: rhinitis (12%), epistaxis, nasal irritation. Injection: nausea (10%), facial flushing, injection site reactions. Long-term use associated with slightly increased cancer risk (EMA warning), limiting recommended treatment duration to under 2 years.

Research Use Only. This information is for educational and research purposes only. Not intended for medical advice or self-medication.

Question 6

How should Calcitonin be stored?

Accepted Answer

Nasal spray: store at room temperature (up to 25°C) before opening, 2-8°C after. Injection: 2-8°C. Salmon calcitonin is more stable than human calcitonin due to increased hydrophobicity.

Question 7

What is the regulatory status of Calcitonin?

Accepted Answer

FDA-approved (Miacalcin, Fortical) for osteoporosis, Paget's disease, hypercalcemia. EMA limits use to short treatment courses due to cancer signal. WADA: not prohibited.

Question 8

Where can I find research studies on Calcitonin?

Accepted Answer

Scientific studies on Calcitonin can be found in peer-reviewed journals through databases like PubMed and Google Scholar.

Question 9

What quality standards should Calcitonin meet for research?

Accepted Answer

Research-grade Calcitonin should meet high purity standards, typically >95% purity, with proper analytical certification and storage requirements.

Calcitonin