Teriparatide
Also known as: PTH(1–34), Forteo, Bonsity, LY333334
Teriparatide is recombinant PTH(1–34), a bone-forming osteoporosis medicine. Its intermittent daily action, fracture evidence and revised osteosarcoma warning differ from continuous PTH exposure and from an absolute two-year lifetime prohibition.
Quick Facts
The active PTH fragment
Teriparatide reproduces the first 34 amino acids of human parathyroid hormone. Known as Forteo and Bonsity and developed under code LY333334, it stimulates formation of new bone rather than primarily slowing resorption. It was approved in the United States in 2002.
Why a daily pulse builds bone
The molecule activates PTH1 receptors on osteoblasts. Continuous excess PTH can promote bone breakdown, while a brief daily teriparatide pulse stimulates formation more than resorption. Bone density and strength increase over months. In the Fracture Prevention Trial in postmenopausal women with prior vertebral fractures, new vertebral-fracture risk was about 65% lower than placebo. An antiresorptive drug often follows the bone-anabolic course to maintain gains.
Supporting references: fractures.
Sources: [1]
How the label changed
| Period | Label context |
|---|---|
| 2002 | Approval with an osteosarcoma boxed warning from high lifelong rat exposure, plus a two-year cumulative limit |
| 2020 | Boxed warning removed after human data did not identify an increased osteosarcoma signal; a standard warning remained |
| Current reported label | Use beyond two years is considered only for someone who remains at high fracture risk |
Supporting references: Approved.
Sources: [2]
High-fracture-risk osteoporosis
Indications include osteoporosis in postmenopausal women, men with primary or hypogonadal osteoporosis, and glucocorticoid-induced osteoporosis. It is generally reserved for high fracture risk rather than mild disease as a first-line treatment.
Calcium effects and other precautions
Joint pain, other pain, nausea, dizziness, leg cramps and a temporary post-dose orthostatic blood-pressure drop are reported. Transient increases in blood or urine calcium and skin calcium deposits, including calciphylaxis, are more serious considerations. Osteosarcoma remains a precaution based on the rat findings even after removal of the boxed warning. People with increased baseline risk, such as Paget disease or previous skeletal radiation, should avoid it under the described product context.
References and further reading
This reference draws on Superpower’s Peptide Library and the research linked below. Peptide Dossier’s editorial team adapted and integrated the material on .
- 10.1056/NEJM200105103441904Why a daily pulse builds boneCited in: Why a daily pulse builds bone
- uspl.lilly.comHow the label changedCited in: How the label changed
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Disclaimer: This article is for informational and educational purposes only. It is not intended as medical advice. The information presented is based on published research and should not be used as a substitute for professional medical guidance. Always consult a qualified healthcare provider before starting any peptide protocol. Some peptides discussed may not be approved for human use by the FDA or equivalent regulatory bodies.