PeptideHormone

Calcitonin

The calcium-lowering counterpart to PTH.

EndogenousEstablished

Identity

Class
Peptide hormone (32 aa)
Source
Thyroid parafollicular (C) cells
Receptor
Calcitonin receptor, a class B GPCR

Key properties

Molecular weight
~3,417.9 Da
Half-life (native)
~10 min
Model dosing

Approximate values for the native hormone. Engineered analogs are often deliberately larger and far longer-acting.

Mechanism

Calcitonin lowers blood calcium chiefly by inhibiting osteoclast-mediated bone resorption, opposing PTH. Its physiological role in adult humans is comparatively modest, but the pathway is pharmacologically useful.

Reference notes

  • Calcitonin opposes PTH — lowering rather than raising calcium.
  • It works mainly by restraining osteoclasts (the bone-resorbing cells).
  • Its everyday role in human calcium balance is smaller than PTH's.

Selected literature

Curated peer-reviewed reviews, sourced from PubMed. Selected for relevance, not exhaustive — open any entry on PubMed for the full record and its primary citations.

  1. 1.Calcitonin · , 2006 · PMID 29999768
  2. 2.Calcitonin · Current medicinal chemistry, 1999 · PMID 10519914