Teriparatide Overview
Mechanism of Action
Teriparatide is recombinant human parathyroid hormone (1-34) — the first 34 amino acids of the 84-amino-acid human PTH molecule. Unlike most compounds listed on this site, it is an FDA-approved prescription medicine (brand names Forteo by Eli Lilly and Bonsity), not a research compound. Given once daily, intermittent PTH (1-34) exposure preferentially stimulates osteoblast activity, which increases bone formation and bone mineral density. It is also known as PTH (1-34), rhPTH(1-34), and recombinant human parathyroid hormone (1-34).
Approximately 1 hour after subcutaneous injection (systemic exposure).
Timing
Once daily, at the same time each day
Injection Site
Subcutaneous injection into the thigh or the abdominal wall
Food
Can be administered regardless of food intake.
Teriparatide Dosing Protocol
FDA-Labeled Protocol
Per prescriber20 mcg/day
FDA-labeled dose for osteoporosis at high risk of fracture: 20 mcg subcutaneously once daily. The former two-year lifetime limit and the boxed osteosarcoma warning have been removed from the U.S. label.
Teriparatide Expected Timeline
Month 1
Dosing established; monitor for orthostatic symptoms after early doses.
Months 3-6
Bone-formation markers rise on lab testing.
Months 12-24
Measured increases in bone mineral density on DXA in the labeled population.
Teriparatide Side Effects
Transient orthostatic hypotension in the hours after the first several doses
Nausea
Injection-site reactions
Leg cramps
Transient increase in serum calcium
Teriparatide Research Studies
No studies referenced.
Teriparatide FAQ
Is teriparatide a research peptide?
No. Teriparatide is an FDA-approved prescription medicine (brand names Forteo and Bonsity), unlike most of the research compounds listed on this site.
What is the labeled dose?
The FDA label is 20 mcg subcutaneously once daily, for osteoporosis in people at high risk of fracture.
How is it different from full parathyroid hormone?
Teriparatide is only the first 34 amino acids of the 84-amino-acid human PTH molecule, which is the biologically active fragment.
Does it still carry the osteosarcoma boxed warning and two-year limit?
No. The boxed osteosarcoma warning and the two-year lifetime treatment limit were removed from the U.S. label.
What vial and reconstitution do the calculator defaults use?
The calculator defaults assume a 1 mg vial reconstituted with 1 mL of bacteriostatic water, giving 1,000 mcg/mL, so a 20 mcg dose is 0.02 mL (2 units on a U-100 syringe). Your supplier's vial may differ — change the vial size to match.