Parathyroid hormone (PTH) analogues

Daily injections of a PTH fragment that build new bone. Anabolic, unlike the drugs that only slow bone loss.

Updated Nov 1, 2026

What they are

Peptides that act on the PTH type 1 receptor. Given once a day under the skin, in short pulses, they stimulate osteoblasts more than osteoclasts, so bone mass and strength increase. They are used for severe osteoporosis at high fracture risk, usually for a limited time and then followed by an antiresorptive.

Mechanism of action

Continuous high PTH, as in hyperparathyroidism, mainly drives resorption. Brief daily peaks instead activate the PTH1 receptor on osteoblasts and their precursors (a G-protein–coupled receptor that raises cAMP), increase their number and activity and reduce their death, and favour formation over resorption. New bone is laid down on trabecular and cortical surfaces.

Target: PTH/PTHrP type 1 receptor (PTH1R), a G-protein–coupled receptor on osteoblasts

Drugs in this class

Others in the class

Abaloparatide

Test yourself

Think of the answer, then tap the question to see it.

Why does once-daily teriparatide build bone while hyperparathyroidism destroys it?

Short daily peaks of PTH stimulate osteoblasts more than osteoclasts; continuous high PTH mainly drives resorption.

Which conditions are avoided with PTH analogues because of osteosarcoma risk?

Paget disease of bone, open epiphyses (children), previous radiation to the skeleton, and bone cancer or metastases.

What is usually given after a course of a PTH analogue, and why?

An antiresorptive such as a bisphosphonate or denosumab, so the new bone is not lost once the anabolic drug stops.

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