{"id":"teriparatide","name":"Teriparatide","aliases":["Forteo","Forsteo","PTH(1-34)","parathyroid hormone 1-34","recombinant human parathyroid hormone"],"url":"https://lyoresearch.com/compounds/teriparatide","class":{"id":"endocrine-medicines","name":"Bone and endocrine peptide medicines","url":"https://lyoresearch.com/classes/endocrine-medicines"},"summary":"Teriparatide is the first 34 amino acids of human parathyroid hormone, given as a daily injection for severe osteoporosis. Continuous parathyroid hormone strips bone; a brief daily pulse builds it — which is why the drug works and the hormone's excess does not. In the 1,637-woman trial behind its approval, new spinal fractures fell from 14% to 5% over about 21 months and non-spinal fragility fractures roughly halved. It is a prescription medicine, approved everywhere, with a long safety record; the original two-year lifetime limit was lifted by the FDA in 2020.","overall_grade":"A","overall_grade_meaning":"established in humans","human_trials":"Fracture Prevention Trial (n=1,637) + head-to-head VERO trial","regulatory_status":"Approved (Rx)","molecule":{"formula":"C181H291N55O51S2","molecular_weight":"4118","cas":"52232-67-4","pubchem_cid":16133850,"note":null},"pharmacokinetics":{"basis":"label","route":"Subcutaneous injection, once daily","half_life":"About 1 hour","licensed_regimen":"20 mcg subcutaneously once daily","product":"Forteo","source":{"title":"Forteo prescribing information (DailyMed)","url":"https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=aae667c5-381f-4f92-93df-2ed6158d07b0"}},"outcomes":[{"outcome":"Vertebral fracture risk (postmenopausal osteoporosis)","grade":"A","grade_meaning":"established in humans","effect_size":"large","adverse":false,"human_studies":"1 large RCT (n=1,637, median 21 mo)","evidence":"New spinal fractures in 14% on placebo against 5% and 4% on the two teriparatide doses — a relative risk of about 0.35. The trial was stopped early, on a rat osteosarcoma signal rather than efficacy, and still showed this.","references":[{"citation":"Neer RM, Arnaud CD, Zanchetta JR, et al. Effect of parathyroid hormone (1-34) on fractures and bone mineral density in postmenopausal women with osteoporosis.","where":"N Engl J Med, 2001","url":"https://pubmed.ncbi.nlm.nih.gov/11346808/"}],"verbatim":{"text":"New vertebral fractures occurred in 14 percent of the women in the placebo group and in 5 percent and 4 percent, respectively, of the women in the 20-microg and 40-microg parathyroid hormone groups; the respective relative risks of fracture in the 20-microg and 40-microg groups, as compared with the placebo group, were 0.35 and 0.31 (95 percent confidence intervals, 0.22 to 0.55 and 0.19 to 0.50).","citation":"Neer RM, Arnaud CD, Zanchetta JR, et al. Effect of parathyroid hormone (1-34) on fractures and bone mineral density in postmenopausal women with osteoporosis.","url":"https://pubmed.ncbi.nlm.nih.gov/11346808/"}},{"outcome":"Non-vertebral fracture risk","grade":"A","grade_meaning":"established in humans","effect_size":"moderate","adverse":false,"human_studies":"Same RCT","evidence":"Non-spinal fragility fractures fell from 6% to 3% — relative risk about 0.47. Hip fractures specifically were too few to analyse in this trial.","references":[{"citation":"Neer RM, Arnaud CD, Zanchetta JR, et al. Effect of parathyroid hormone (1-34) on fractures and bone mineral density in postmenopausal women with osteoporosis.","where":"N Engl J Med, 2001","url":"https://pubmed.ncbi.nlm.nih.gov/11346808/"}]},{"outcome":"Bone mineral density","grade":"A","grade_meaning":"established in humans","effect_size":"large","adverse":false,"human_studies":"Same RCT + many","evidence":"Spine density rose 9–13 percentage points more than placebo, femoral neck 3–6 — the largest gains of any osteoporosis drug — with a small loss at the wrist shaft.","references":[{"citation":"Neer RM, Arnaud CD, Zanchetta JR, et al. Effect of parathyroid hormone (1-34) on fractures and bone mineral density in postmenopausal women with osteoporosis.","where":"N Engl J Med, 2001","url":"https://pubmed.ncbi.nlm.nih.gov/11346808/"}],"verbatim":{"text":"As compared with placebo, the 20-microg and 40-microg doses of parathyroid hormone increased bone mineral density by 9 and 13 more percentage points in the lumbar spine and by 3 and 6 more percentage points in the femoral neck; the 40-microg dose decreased bone mineral density at the shaft of the radius by 2 more percentage points.","citation":"Neer RM, Arnaud CD, Zanchetta JR, et al. Effect of parathyroid hormone (1-34) on fractures and bone mineral density in postmenopausal women with osteoporosis.","url":"https://pubmed.ncbi.nlm.nih.gov/11346808/"}},{"outcome":"Versus risedronate (head-to-head)","grade":"A","grade_meaning":"established in humans","effect_size":"moderate","adverse":false,"human_studies":"VERO RCT (n=1,360, 24 mo)","evidence":"In a direct comparison against a standard bisphosphonate in women with severe osteoporosis, teriparatide produced fewer new vertebral fractures. The result that moved it from second-line to first-line for the highest-risk patients in many guidelines.","references":[{"citation":"Kendler DL, Marin F, Zerbini CAF, et al. Effects of teriparatide and risedronate on new fractures in post-menopausal women with severe osteoporosis (VERO): a multicentre, double-blind, double-dummy, randomised controlled trial.","where":"Lancet, 2018","url":"https://pubmed.ncbi.nlm.nih.gov/?term=VERO+teriparatide+risedronate+Kendler+Lancet+2018"}]},{"outcome":"Adverse effects","grade":"A","grade_meaning":"established in humans","effect_size":"small","adverse":true,"human_studies":"Approval trial + 20 years of surveillance","evidence":"Nausea, headache, leg cramps, transient high calcium. The rat osteosarcoma finding that limited use to two years was never seen at excess in people; the FDA removed the limit and the boxed warning in 2020.","references":[{"citation":"Neer RM, Arnaud CD, Zanchetta JR, et al. Effect of parathyroid hormone (1-34) on fractures and bone mineral density in postmenopausal women with osteoporosis.","where":"N Engl J Med, 2001","url":"https://pubmed.ncbi.nlm.nih.gov/11346808/"},{"citation":"Teriparatide (Forteo) prescribing information — 2020 label update removing the two-year limit and boxed warning.","where":"FDA","url":"https://www.accessdata.fda.gov/scripts/cder/daf/"}],"verbatim":{"text":"Parathyroid hormone had only minor side effects (occasional nausea and headache).","citation":"Neer RM, Arnaud CD, Zanchetta JR, et al. Effect of parathyroid hormone (1-34) on fractures and bone mineral density in postmenopausal women with osteoporosis.","url":"https://pubmed.ncbi.nlm.nih.gov/11346808/"}}],"regions":[{"region":"European Union","status":"Approved, prescription-only","note":"Centrally authorised (Forsteo) since 2003; biosimilars since 2017."},{"region":"United States","status":"Approved, prescription-only","note":"FDA-approved 2002 (Forteo). Two-year lifetime limit and osteosarcoma boxed warning removed in November 2020."},{"region":"United Kingdom","status":"Licensed, prescription-only","note":"Licensed; NICE-recommended for specific high-risk groups."},{"region":"Australia","status":"Registered, prescription-only","note":"On the ARTG; PBS-subsidised for severe osteoporosis."},{"region":"Canada","status":"Authorised, prescription-only","note":"Health Canada-authorised."},{"region":"Sport (WADA)","status":"Not prohibited","note":"Parathyroid hormone analogues are not on the Prohibited List."}],"faq":[{"q":"Is teriparatide a steroid?","a":"No. It is a peptide hormone fragment — 34 amino acids of parathyroid hormone — with no anabolic-steroid activity. 'Anabolic' here means it builds bone."},{"q":"Why was there a two-year limit?","a":"Rats given lifelong high doses developed osteosarcoma. Twenty years of human use found no excess, and the FDA removed the limit and the boxed warning in 2020. Many prescribers still use two-year courses, followed by a drug that holds the gain."},{"q":"Is it better than bisphosphonates?","a":"For severe osteoporosis, the head-to-head VERO trial found fewer new spinal fractures with teriparatide than with risedronate. It is more expensive, injected daily, and usually followed by a bisphosphonate anyway."}],"references":[{"cite":"Neer RM, Arnaud CD, Zanchetta JR, et al. Effect of parathyroid hormone (1-34) on fractures and bone mineral density in postmenopausal women with osteoporosis.","where":"N Engl J Med, 2001","url":"https://pubmed.ncbi.nlm.nih.gov/11346808/","note":"Fracture Prevention Trial; 1,637 women; the approval trial."},{"cite":"Kendler DL, Marin F, Zerbini CAF, et al. Effects of teriparatide and risedronate on new fractures in post-menopausal women with severe osteoporosis (VERO): a multicentre, double-blind, double-dummy, randomised controlled trial.","where":"Lancet, 2018","url":"https://pubmed.ncbi.nlm.nih.gov/?term=VERO+teriparatide+risedronate+Kendler+Lancet+2018","note":"Head-to-head; 1,360 women; 24 months."},{"cite":"Teriparatide (Forteo) prescribing information — 2020 label update removing the two-year limit and boxed warning.","where":"FDA","url":"https://www.accessdata.fda.gov/scripts/cder/daf/","note":"Regulatory status."}],"last_reviewed":"2026-09-10","literature_searched_to":"2026-09-10","changelog":[{"date":"2026-09-10","note":"Initial publication. Grade A on the Fracture Prevention Trial and VERO."}],"license":"CC BY 4.0 — cite as “LYO Research” with a link.","methodology":"https://lyoresearch.com/methodology"}