Overview

A peptide that genuinely builds bone rather than merely slowing its loss — the first anabolic osteoporosis therapy. It is also a clean example of pulsatile versus continuous hormone exposure producing opposite biological effects.

FDA ApprovedFDA-approved for severe osteoporosis at high fracture risk. The osteosarcoma boxed warning and 2-year lifetime limit were removed in 2020–21 following long-term surveillance data.

At a glance

Regulatory status	FDA-approved for severe osteoporosis at high fracture risk. The osteosarcoma boxed warning and 2-year lifetime limit were removed in 2020–21 following long-term surveillance data.
Drug class	Recombinant human parathyroid hormone fragment — first 34 amino acids
Route	Subcutaneous, once daily
Half-life	~1 hour
Evidence rating	5/5 Very strong Evidence rating 5 out of 5: Very strong Multiple phase 3 randomized trials plus regulatory approval in a major market.
Studied in	Fracture Prevention Trial and numerous subsequent randomized trials, including head-to-head comparisons against bisphosphonates.

How it works

Intermittent daily PTH receptor activation preferentially stimulates osteoblast activity over osteoclast activity, producing net bone formation. Continuous PTH elevation, as in hyperparathyroidism, does the reverse and causes bone loss. The dosing interval is the whole mechanism.

Evidence base

Rated 5 of 5 — Very strong. Multiple phase 3 randomized trials plus regulatory approval in a major market.

Fracture-endpoint randomized trials — the strongest evidence class in osteoporosis.

Benefits & potential uses

Bars indicate how well each claim is supported: three = strong human evidence, two = moderate, one = preliminary or preclinical.

Reduces vertebral fractures Strong evidence

Roughly 65% reduction in new vertebral fractures in the pivotal trial — among the largest effects in osteoporosis therapeutics.
Reduces non-vertebral fractures Strong evidence

Approximately 53% reduction in non-vertebral fragility fractures.
Genuinely anabolic Strong evidence

Increases bone mineral density and improves trabecular microarchitecture, rather than only inhibiting resorption.
Superior to bisphosphonates in high-risk patients Strong evidence

The VERO trial showed fewer fractures than risedronate in patients with severe osteoporosis.
Accelerates fracture and non-union healing Moderate evidence

Supported by smaller studies and increasingly used off-label for this purpose.

Risks, cons & cautions

Bars indicate seriousness: three = serious or common, two = moderate, one = minor.

Historic osteosarcoma signal Moderate evidence

Rats given high lifetime doses developed osteosarcoma. Long-term human surveillance did not confirm the risk, and the boxed warning was removed — but caution persists in patients with pre-existing bone malignancy risk.
Hypercalcemia Moderate evidence

Transient elevations are common; persistent hypercalcemia requires dose review.
Orthostatic hypotension Moderate evidence

Occurs particularly with early doses; patients are advised to inject where they can sit or lie down.
Bone density loss after stopping Serious

Gains are lost unless followed by an antiresorptive agent. Sequencing is essential, not optional.
Nausea, leg cramps, headache Minor

Common but usually manageable.
Contraindicated with prior skeletal radiation Serious

Along with Paget disease, unexplained alkaline phosphatase elevation, and bone metastases.

Who should avoid it

Prior external beam or implant radiation to the skeleton
Paget disease of bone
Bone metastases or skeletal malignancy
Pre-existing hypercalcemia
Pregnancy

If used under medical supervision, monitor

Serum calcium
Bone mineral density by DXA
Renal function
Plan for sequential antiresorptive therapy before stopping

Interactions

Not exhaustive. Always have a pharmacist or physician review your full medication list — including supplements.

Digoxin — hypercalcemia may predispose to digoxin toxicity
Calcium and vitamin D supplements — needed for efficacy but contribute to hypercalcemia risk
Thiazide diuretics — additive hypercalcemia
Bisphosphonates — concurrent use may blunt the anabolic effect; sequential use after teriparatide is standard

Regulatory & legal status

Prescription drug; biosimilar and generic versions are now available.

Infographic

Teriparatide — benefits & risks at a glance Download SVG

Where to read further

We link to live literature searches rather than a frozen citation list, so you always see current results — including anything published after our last review.

osteoporosisboneanabolicapprovedfracture prevention

Related peptides in Bone, Muscle & Other

Terms used on this page

Osteoblast: An osteoblast is the mesenchymal-lineage cell that lays down and mineralises bone matrix, and its activity sets the formation half of the bone remodelling cycle.
Dosing Interval: The dosing interval is the time between successive doses, and its ratio to the half-life determines how far concentrations swing and how much drug accumulates.
Bone Remodelling: Bone remodelling is the lifelong coupled cycle in which osteoclasts resorb a packet of bone and osteoblasts refill it, continuously renewing the skeleton without changing its shape.
Osteoclast: An osteoclast is a large multinucleated cell of haematopoietic origin that dissolves bone mineral and digests its collagen, providing the resorption half of bone remodelling.
Phase 3 Trial: A Phase 3 trial is the large confirmatory study, powered for a prespecified clinical endpoint, on which a marketing application and the resulting product label are built.
Bone Mineral Density (BMD): Bone mineral density is the mineral content of bone per unit of projected area measured by DXA, expressed as grams per square centimetre and reported clinically as a T-score.

This page is educational information, not medical advice. It cannot account for your medical history, medications, or risk factors. Do not start, stop or change any treatment based on it. Speak to a qualified healthcare professional who knows your case.