Teriparatide
Aliases: Forteo · PTH(1-34)
Last verified: 2026-09-23
The short version
A parathyroid hormone fragment (1–34) — an anabolic osteoporosis drug: unlike antiresorptives, it builds new bone.
Identity & type
- Molecular type
- analog
- Origin
- A parathyroid hormone fragment (1–34) — an anabolic osteoporosis drug: unlike antiresorptives, it builds new bone.
Mechanism of action
Intermittent PTH1R activation → net bone formation (osteoblasts).
Dosing & routes
Official / clinical context
Approved drug — indications, dosing and warnings are defined by the official label. 20 mcg SC daily, max 24 months.
Regulator-approved labeling and published study designs — never a recommendation.
Community-reported practice
20 mcg SC daily, max 24 months. Forteo: measurable bone-density gains within 12–18 months in osteoporosis; users report less pain and better stability. Course limited to 24 months.
Unverified self-reports. Not medical advice. Not endorsement.
Expected effects (community)
Forteo: measurable bone-density gains within 12–18 months in osteoporosis; users report less pain and better stability. Course limited to 24 months.
Protocol — official vs community
Official / label
Forteo (and biosimilars), for postmenopausal osteoporosis, osteoporosis in men, and glucocorticoid-induced osteoporosis at high fracture risk: 20 mcg SC once daily into the thigh or abdomen.
Duration: Maximum 24 months of lifetime use (2 years). Phase 3: ~65% reduction in new vertebral fractures.
Intermittent PTH1R activation is anabolic — it builds new bone rather than only slowing loss, which is the entire rationale for the daily-single-injection schedule. The 24-month cap comes from the rodent osteosarcoma signal; anabolic effect persists partially after stopping, and antiresorptive therapy usually follows.
Community (anecdotal)
Mirrors the label where gray-market product appears: 20 mcg SC daily.
- Cycle:
- Community users sometimes compress to 6–12 month 'anabolic windows' rather than the full 24 months.
- Break:
- Not applicable — the cap is lifetime cumulative, not cyclable.
Interest concentrates among biohackers tracking bone density; unlike most gray-market peptides, the anabolic-window concept here has real trial logic behind it, and the 24-month lifetime cap is a hard pharmacological fact, not folklore.
Human evidence
Phase III: −65% new vertebral fractures.
Preclinical evidence
The preclinical phase was completed and submitted to regulators as part of registration; pharmacology and toxicology details are part of the official label.
Known risks
- Hypercalcemia, dizziness, cramps; osteosarcoma warning (rodents).characterized
Teal: characterized in clinical/labeling contexts. Amber: theoretical or reported outside controlled settings.
Unknowns & evidence gaps
- Real-world data outside controlled trials