Teriparatide
Teriparatide (PTH 1-34 / Forteo)
Anabolic Parathyroid Hormone Fragment for Bone Health
What is Teriparatide?
Teriparatide is the recombinant form of the first 34 amino acids of human parathyroid hormone (PTH 1-34), the biologically active N-terminal fragment of the 84-amino-acid endogenous parathyroid hormone. It is produced via recombinant DNA technology in Escherichia coli. Teriparatide is the only FDA-approved anabolic (bone-building) agent for osteoporosis treatment in the United States, available under the brand names Forteo and Bonsity, and represents a fundamentally different pharmacological approach to bone loss compared to antiresorptive agents such as bisphosphonates and denosumab.
The distinction between teriparatide's anabolic effects and the catabolic effects of endogenous PTH overproduction lies entirely in the pattern of exposure. Chronic continuous elevation of parathyroid hormone (as occurs in primary hyperparathyroidism) drives net bone resorption and cortical bone thinning. Intermittent administration of low-dose teriparatide (a daily subcutaneous injection that produces a transient pulse of PTH activity) produces the opposite effect: net bone formation exceeds resorption. The mechanism involves direct stimulation of osteoblasts (bone-forming cells), suppression of osteoblast apoptosis, activation of resting bone surfaces previously not undergoing remodeling, and indirect modulation of osteoclast activity. The result is an increase in both trabecular bone volume and cortical bone thickness.
Clinical evidence for teriparatide is robust. In the pivotal randomized controlled trial in postmenopausal women with prior vertebral fractures (n=1,637), 20 mcg daily teriparatide over a median of 21 months reduced new vertebral fracture risk by 65% and nonvertebral fragility fracture risk by 53%, while increasing lumbar spine bone mineral density (BMD) by 9% and femoral neck BMD by 3%. A 2024 systematic review and meta-analysis comparing teriparatide with other anabolic agents confirmed its substantial benefits in lumbar spine and hip BMD gains and fracture risk reduction, particularly in patients at high fracture risk.
Teriparatide is FDA-approved for postmenopausal women with osteoporosis at high fracture risk, men with primary or hypogonadal osteoporosis at high fracture risk, and men and women with glucocorticoid-induced osteoporosis at high fracture risk. Treatment duration is limited to 24 months cumulative lifetime due to preclinical findings of osteosarcoma in rats given very high doses over extended periods -- a risk that has not been demonstrated in human clinical trials.
Research Supply
Source high-purity Teriparatide for your research
Dosage Guide
Route: Subcutaneous injection, once daily
Dosing Schedule
| Period | Dose |
|---|---|
| Postmenopausal osteoporosis | 20 mcg once daily SQ (maximum 24 months lifetime) |
| Male osteoporosis (primary or hypogonadal) | 20 mcg once daily SQ (maximum 24 months lifetime) |
| Glucocorticoid-induced osteoporosis | 20 mcg once daily SQ (maximum 24 months lifetime) |
Reconstitution
Injection Volumes
| Dose | Volume | Syringe Units |
|---|---|---|
| 20 mcg | 0.08 mL | Fixed dose -- pen auto-delivers 20 mcg per actuation |
Administration Tips
- The first injection should be administered while the patient is sitting or lying down -- transient orthostatic hypotension may occur
- Standard injection sites are the thigh and abdominal wall; rotate sites with each injection
- The injection pen should be refrigerated at all times -- do not freeze
- After removing from the refrigerator, allow the pen to reach room temperature before injecting
- Following teriparatide cessation, transition to an antiresorptive therapy (such as a bisphosphonate) is recommended to preserve BMD gains
- Treatment is typically reserved for patients at high or very high fracture risk due to the 24-month lifetime use limit
- Higher doses did not produce superior BMD outcomes and increased side effect rates in dose-response studies
Risks & Side Effects
Commonly Reported
Serious Risks
Osteosarcoma
A black box warning exists based on rat carcinogenicity studies showing osteosarcoma at doses 3 to 60 times the human equivalent dose over the rat lifetime. No cases of osteosarcoma attributable to teriparatide have been confirmed in human clinical trials or post-marketing data, but the theoretical risk informs the 24-month lifetime use restriction.
Hypercalcemia
Clinically significant elevations in serum calcium can occur, particularly in patients with pre-existing conditions predisposing to hypercalcemia (hyperparathyroidism, Paget's disease).
Urolithiasis
Kidney stone formation; pre-existing nephrolithiasis is a relative contraindication.
Contraindications
- Hypersensitivity to teriparatide or any excipient
- Pre-existing hypercalcemia
- Metabolic bone diseases other than primary osteoporosis or glucocorticoid-induced osteoporosis (including Paget's disease of bone)
- Unexplained elevations of alkaline phosphatase
- Prior external beam or implant radiation therapy to the skeleton
- Pediatric patients or young adults with open epiphyses
- Pregnancy and lactation
- Skeletal metastases or prior history of bone malignancy
- History of osteosarcoma
Frequently Asked Questions
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LEGAL DISCLAIMER
The information provided on this page is for educational and informational purposes only and is not intended as medical advice. Teriparatide is FDA-approved under specific brand names for specific indications; use outside those approved indications may be off-label. Always consult with a qualified healthcare professional before starting any peptide therapy. Individual results may vary. Peptides Institute is not responsible for any adverse effects resulting from the use of information provided on this site.