Abaloparatide
An approved daily injection for osteoporosis that builds new bone rather than slowing its loss. Phase 3 showed a large reduction in vertebral fracture.
Bone & Muscle
Teriparatide
The first bone-building osteoporosis drug, approved since 2002. Reduces vertebral fracture substantially and is one of the best-characterised anabolic agents in medicine.
Overview
Continuously high parathyroid hormone dissolves bone — that is what happens in hyperparathyroidism. But a brief daily pulse of the same hormone does the opposite and stimulates bone formation. Teriparatide is the active first 34 amino acids of PTH, given once a day so the body only ever sees the pulse. Bone density rises, particularly in the spine, and vertebral fractures fall sharply.
Recombinant human PTH(1-34). Intermittent daily administration produces transient PTH1 receptor activation on osteoblasts and osteocytes, favouring osteoblast survival, reduced sclerostin expression and net anabolic remodelling — the opposite of the catabolic effect of continuous exposure. The pivotal Fracture Prevention Trial reported a 65% reduction in new vertebral fractures and a 53% reduction in nonvertebral fragility fractures over a median 21 months. Anabolic gains are not maintained after discontinuation without sequential antiresorptive therapy.
Research areas
OsteoporosisFracture preventionBone anabolism
Dosing reported in the literature
Every protocol below is reproduced from a published study or approved labelling, with its source named. These are records of what was studied — not recommendations, and not a suggestion that any of them is appropriate for any person.
| Protocol as reported | Source |
|---|---|
| 20 mcg subcutaneously once daily into the thigh or abdomen | Approved product labelling |
| 20 mcg or 40 mcg daily versus placebo over a median 21 monthsThe 40 mcg arm gave no additional fracture benefit and more hypercalcaemia, which is why 20 mcg is the approved dose. | Neer et al., New England Journal of Medicine 2001 |
Trial status
Pivotal phase 3 completed; extensive post-approval literature and multiple biosimilars.
Reported safety signals
- Transient hypercalcaemia is common; baseline hypercalcaemia is a contraindication.
- Orthostatic hypotension can occur in the hours after the first several doses.
- A rodent osteosarcoma signal drove a historical boxed warning; the boxed warning has since been removed but the cumulative-use limit remains.
- Bone gains reverse after stopping unless followed by an antiresorptive agent.
Common questions
Why does the same hormone build bone in one pattern and destroy it in another?
Duration of receptor signalling determines which cell population dominates the response. A short daily pulse favours osteoblast survival and formation; continuous exposure favours RANKL-driven osteoclast activity and resorption. It is one of the clearest examples in endocrinology that the pattern of a signal matters as much as its size.
Primary sources
Medical disclaimer
This page is for informational and research purposes only. Nothing here constitutes medical advice. The compounds discussed are research chemicals. Consult a qualified clinician before starting any protocol.
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