Research information only. PrecisePep is an educational library. It is not medical advice and is not intended to assist, encourage or enable self-administration. The compounds documented here are research chemicals — most are not approved for human use. Read the full disclaimer.
PrecisePep/Peptide Library/Teriparatide
Bone & Skeletal
Forteo® · Bonsity® · PTH(1–34) · recombinant human parathyroid hormone 1-34
The first drug that built bone rather than slowing its loss — a 34-residue fragment of parathyroid hormone that works only because it is given intermittently. Continuous exposure to the same molecule does the opposite.
Teriparatide is the answer to a question this library gets asked constantly and rarely answers honestly: is there a peptide that builds bone? Yes. It has been approved since 2002, it has randomised fracture-reduction data, it is a 34-amino-acid peptide, and you get it on prescription.
What makes it interesting pharmacologically is that it is the same hormone that causes bone loss in hyperparathyroidism. Continuously elevated parathyroid hormone drives net resorption and demineralises the skeleton. Given as a single daily pulse that clears within a few hours, the identical molecule drives net formation. The dose is not what separates the two effects — the time course is. That is one of the cleanest demonstrations in endocrinology that a receptor's downstream consequence depends on the shape of the signal, not just its size.[1]
The pivotal fracture trial in postmenopausal women with prior vertebral fracture reported substantial reductions in new vertebral and non-vertebral fractures against placebo, and was stopped early — for reasons that had nothing to do with those results.[2]
It is a prescription medicine, not a research compound, and this page publishes no grey-market dosing for it. It is here because the conditions index names osteoporosis, and because the honest answer to "is there a peptide for bone density?" is that the peptide class solved this in 2002 through the ordinary regulatory route. A page that listed GH secretagogues under bone health and omitted teriparatide would be misleading by selection.
PTH1R agonism, intermittently. Teriparatide binds the type 1 parathyroid hormone receptor on osteoblasts and osteoblast precursors. A brief daily pulse increases osteoblast number and survival — reducing osteoblast apoptosis and recruiting lining cells back into active formation — before the resorptive response has time to catch up.
The anabolic window. Formation rises first; resorption follows several months later. The gap between the two curves is where bone is actually gained, and it is why the effect is front-loaded rather than linear. It is also why teriparatide is not a maintenance drug: run long enough, the two curves converge.
Why continuous PTH does the opposite. Sustained receptor occupancy shifts the osteoblast RANKL/osteoprotegerin ratio toward osteoclast activation. Same receptor, same ligand, opposite skeletal outcome — the mechanism behind the bone disease of primary hyperparathyroidism.
Sequencing matters more here than in most drug classes. Giving teriparatide after a potent antiresorptive blunts the anabolic response, because the remodelling machinery it works through has been suppressed. Giving an antiresorptive after teriparatide preserves the gain. Stopping teriparatide without following it with an antiresorptive loses it.[3]
Effects that have been reported. A study-tier entry means a result was published — not that the effect is established, reproducible, or transferable from a rodent to a person.
Highest confidenceReported in peer-reviewed literature, registered clinical trials, or regulatory filings. Note the model: much peptide literature is in vitro or rodent work, not human trial data.
The pivotal randomised placebo-controlled trial in postmenopausal women with prior vertebral fracture reported large reductions in new vertebral fractures and meaningful reductions in non-vertebral fractures over a median of roughly 19 months. Fracture, not bone density, is the endpoint that matters, and this is one of the few agents in any part of this library with it.
Bisphosphonates and denosumab work by slowing bone removal. Teriparatide increases bone formation, producing gains in bone mineral density — particularly at the lumbar spine — that antiresorptives cannot match.
A head-to-head randomised trial in postmenopausal women with severe osteoporosis reported fewer new vertebral and clinical fractures on teriparatide than on an oral bisphosphonate — an active-comparator result rather than a placebo one.
Randomised trial data support use in this population, where bone formation is directly suppressed by the steroid and an anabolic mechanism is the more logical counter.
The original rat carcinogenicity finding — near-lifetime, high-dose exposure in a species that models this poorly — drove a boxed warning and a two-year lifetime cap. Two large claims-based cohort studies found no increase in osteosarcoma in treated patients against unexposed comparators or background incidence. The FDA removed both the boxed warning and the duration limit in November 2020.
Unproven — inference onlyExtrapolated from a known mechanism, receptor profile, or adjacent compound class. Biologically plausible but not directly demonstrated for this compound in this context.
Off-label use in delayed union and atypical femoral fracture is reported in case series and small studies with a coherent mechanistic story. It is not an approved indication and the controlled evidence is thin.
Small studies in periodontal and jaw bone healing exist. Interesting, preliminary, not practice.
Removing the two-year limit permits longer use, but the anabolic window still closes. Duration became a clinical judgement rather than a regulatory one — which is not the same as evidence that longer is better.
Uncontrolled reportsAggregated from research-community logs, forums, vendor literature and self-reported experience. Uncontrolled, unverified, subject to placebo, polypharmacy and product-purity confounds. Lowest evidentiary weight.
Patient reporting centres on injection fatigue over a course measured in years rather than on the drug itself.
Historically the dominant complaint. Biosimilar and generic entry has changed this substantially in some markets.
The two most frequently mentioned tolerability issues, usually early and usually manageable.
A recombinant peptide sold in a refrigerated pre-filled pen with a metered daily dose is a poor fit for the research-chemical supply chain. Where it appears, diversion of licensed product is more plausible than synthesis.
Adverse effects, contraindications and unknowns. The grey-market tier is where under-reporting is worst: uncontrolled use produces no systematic safety surveillance at all, so absence of a reported harm is not evidence of safety.
Highest confidenceReported in peer-reviewed literature, registered clinical trials, or regulatory filings. Note the model: much peptide literature is in vitro or rodent work, not human trial data.
Serum calcium peaks four to six hours after a dose and usually returns to baseline by sixteen to twenty-four hours. Persistent hypercalcaemia warrants investigation, and pre-existing hypercalcaemia is a contraindication.
Typically within four hours of the first few injections and self-limiting. The label advises the first doses be given where the patient can sit or lie down.
The common adverse events across the trial programme.
Use with caution in active or recent urolithiasis; the calcium handling change is real even where serum calcium stays in range.
Paget disease of bone, unexplained elevated alkaline phosphatase, open epiphyses, prior skeletal radiotherapy and skeletal malignancy remain contraindications or cautions even after the boxed warning was withdrawn. The warning was removed because the human data did not support a population-wide signal — not because risk is zero in people who already have one.
Unproven — inference onlyExtrapolated from a known mechanism, receptor profile, or adjacent compound class. Biologically plausible but not directly demonstrated for this compound in this context.
The gain is not self-sustaining. Stopping without transitioning to an antiresorptive gives much of it back, and this is the most common way the drug is wasted.
Prior bisphosphonate or denosumab exposure attenuates the anabolic response, particularly at the hip. Sequencing is a real determinant of benefit.
Removing the two-year cap outran the duration most of the trial evidence covers. Longer courses are permitted; they are not well characterised.
Uncontrolled reportsAggregated from research-community logs, forums, vendor literature and self-reported experience. Uncontrolled, unverified, subject to placebo, polypharmacy and product-purity confounds. Lowest evidentiary weight.
The single most-mentioned effect in patient reporting.
Consistent with the labelled orthostatic effect and usually settles.
Reported at rates typical for a daily subcutaneous pen.
Figures below are documented, not recommended. Study ranges come from published protocols in the stated model; grey-market ranges are what the research community reports using and carry no safety validation of any kind.
Highest confidenceReported in peer-reviewed literature, registered clinical trials, or regulatory filings. Note the model: much peptide literature is in vitro or rodent work, not human trial data.
A single fixed dose — no titration, no weight adjustment. Into the thigh or abdominal wall. The pen delivers 28 doses.
The lifetime two-year limitation was removed with the boxed warning in November 2020. Duration is now a clinical decision weighing continued fracture risk against diminishing anabolic return.
Standard practice on completion is transition to a bisphosphonate or denosumab to consolidate the gain. This is not optional in any meaningful sense.
| Parameter | Value | Note |
|---|---|---|
| Dose | 20 mcg daily | Fixed — no titration |
| Route | Subcutaneous, thigh or abdomen | Pre-filled pen, 28 doses |
| Duration | No regulatory limit since Nov 2020 | Previously capped at 24 months lifetime |
| Calcium | Peaks 4–6 h post-dose | Back to baseline by 16–24 h |
| After stopping | Antiresorptive follow-on | Otherwise the gain is largely lost |
| Storage | 2–8 °C throughout | Refrigerated in use, unlike most pens |
Unproven — inference onlyExtrapolated from a known mechanism, receptor profile, or adjacent compound class. Biologically plausible but not directly demonstrated for this compound in this context.
Where a patient will receive both, giving teriparatide first produces a larger overall result than the reverse order. Well-reasoned, supported by sequencing studies, and still a clinical judgement.
Uncontrolled reportsAggregated from research-community logs, forums, vendor literature and self-reported experience. Uncontrolled, unverified, subject to placebo, polypharmacy and product-purity confounds. Lowest evidentiary weight.
Patients commonly shift the injection to a time when they can sit down afterwards. Sensible and consistent with the label.
Combination effects. Almost no peptide combination has been studied as a combination in humans; stack logic is overwhelmingly mechanistic inference and community practice. Each linked compound has its own page.
Highest confidenceReported in peer-reviewed literature, registered clinical trials, or regulatory filings. Note the model: much peptide literature is in vitro or rodent work, not human trial data.
The best-supported sequence. Anabolic gain followed by antiresorptive consolidation produces larger and more durable density gains than either alone.
Studied in the DATA and DATA-Switch trials, reporting larger density gains than either agent alone. Combination therapy remains uncommon in practice and is not a labelled use.
An anabolic agent cannot build matrix from substrate that is not there. Repletion is assumed by every trial in the programme.
Unproven — inference onlyExtrapolated from a known mechanism, receptor profile, or adjacent compound class. Biologically plausible but not directly demonstrated for this compound in this context.
Suppressed remodelling attenuates the anabolic effect, particularly at the hip. An argument for order, not for avoidance.
Bone responds to load. The pharmacology increases formation capacity; loading directs where it goes. Well grounded in bone physiology, not a trial finding for this drug.
IGF-1 affects bone turnover, which is the argument usually made for GH stacks in this space. Turnover markers are not fracture reduction, and no secretagogue has ever demonstrated the latter.
Uncontrolled reportsAggregated from research-community logs, forums, vendor literature and self-reported experience. Uncontrolled, unverified, subject to placebo, polypharmacy and product-purity confounds. Lowest evidentiary weight.
Usually by people who have not read the fracture data for either. Teriparatide has it; the secretagogues do not.
Whole schedules — dosing, titration, cycle length, and off-time — as documented in trials, as proposed from mechanism, and as circulated in the research community. Reproduced for study and comparison only.
Highest confidenceReported in peer-reviewed literature, registered clinical trials, or regulatory filings. Note the model: much peptide literature is in vitro or rodent work, not human trial data.
Randomised, placebo-controlled, postmenopausal women with prior vertebral fracture, with calcium and vitamin D supplementation in all arms. Terminated early on the rat carcinogenicity finding rather than on efficacy or human safety.
Guideline-supported for patients at very high fracture risk — teriparatide or abaloparatide first, consolidation second.
Unproven — inference onlyExtrapolated from a known mechanism, receptor profile, or adjacent compound class. Biologically plausible but not directly demonstrated for this compound in this context.
Serum calcium before starting and where symptoms suggest hypercalcaemia; densitometry at intervals; assessment of fracture risk rather than density alone when deciding duration.
Uncontrolled reportsAggregated from research-community logs, forums, vendor literature and self-reported experience. Uncontrolled, unverified, subject to placebo, polypharmacy and product-purity confounds. Lowest evidentiary weight.
Habit and reimbursement have both outlived the regulatory limit that created them.
The approved indication is covered above. This section is about where teriparatide is used beyond it, and about the comparison that matters most to readers of this library — because the bone claim made for growth hormone compounds is made against a drug that already has the fracture data.
Approved for osteoporosis at high fracture risk and for glucocorticoid-induced osteoporosis. The uses below are off-label. The boxed warning and the two-year lifetime cap were both removed in November 2020 after human cohort studies failed to reproduce the rat osteosarcoma signal — but the contraindications in people whose baseline osteosarcoma risk is already elevated remain.
Pathophysiology
Bone density claims are made for growth hormone secretagogues and for IGF-1 analogues on the basis that IGF-1 is involved in bone formation — which it is.
Mechanistic rationale
Turnover markers are not fracture reduction. Teriparatide has randomised trial evidence for reducing vertebral and non-vertebral fractures, and head-to-head evidence against an oral bisphosphonate. No GH secretagogue or IGF-1 analogue has ever demonstrated fracture reduction. If bone is genuinely the goal, the anabolic peptide that treats it has existed since 2002 and is available on prescription.
Community reports
Teriparatide appears in longevity discussion far less often than the GH compounds, despite being the one with the outcome data.
Components carrying the argument: PTH1R — intermittent exposure
Pathophysiology
Delayed union and non-union occur when the fracture healing cascade stalls, and atypical femoral fractures associated with long-term bisphosphonate use are particularly slow to heal.
Mechanistic rationale
Off-label use in non-union and atypical femoral fracture is reported in case series with a mechanistically coherent rationale — an anabolic agent in a setting where bone formation has stalled. The controlled evidence is thin, and this is a specialist decision rather than a general one.
Community reports
Used in orthopaedic practice in selected cases.
Components carrying the argument: Osteoblast recruitment and survival
Pathophysiology
Teriparatide works through the bone remodelling machinery. Potent antiresorptives suppress that machinery.
Mechanistic rationale
Anabolic first, antiresorptive second. Giving teriparatide after a potent antiresorptive blunts the response, particularly at the hip. Stopping teriparatide without following it with an antiresorptive loses much of the gain. Both errors are common, and either wastes an expensive and time-limited course.
Community reports
The two-year course remains the default in practice, held over from a regulatory limit that no longer exists.
Components carrying the argument: The anabolic window
| Question | Position |
|---|---|
| Fracture reduction data? | Yes — vertebral and non-vertebral |
| Any GH compound with the same? | No — turnover markers only |
| Boxed warning | Removed November 2020 |
| Duration cap | Removed — now a clinical judgement |
| Sequence | Anabolic first, then antiresorptive |
| If stopped without follow-on | Much of the gain is lost |
For osteoporosis: teriparatide or abaloparatide for anabolic effect in high fracture risk, consolidated with a bisphosphonate or denosumab; romosozumab where appropriate; adequate vitamin D and calcium; and progressive loading exercise, which directs where the bone goes. Falls prevention matters as much as bone density in older adults, and is consistently under-addressed.
Physical-chemistry reference for laboratory handling of the lyophilised material. Reproduced so that stability and concentration mathematics can be studied — see the calculator for the arithmetic and the reconstitution guide for sterile technique.
None. The licensed product is a refrigerated multi-dose pre-filled pen delivering 20 mcg per actuation. There is no lyophilised research-grade format in normal circulation and this site publishes no reconstitution figures for it.
Refrigerated at 2–8 °C continuously, including during the 28-day in-use period — unlike most injectable pens, it does not get a room-temperature window. Do not freeze. Discard after 28 days in use.
Licensed: 600 mcg/2.4 mL multi-dose pen (28 daily doses of 20 mcg).
A recombinant peptide in aqueous solution held cold for a month. Temperature excursions are the practical failure mode; a pen left out is a discarded pen.
Regulatory status changes and differs by country. This is a summary for orientation, not legal advice — check your own jurisdiction.
Approved prescription medicine. Licensed as Forteo, Bonsity and several biosimilars for postmenopausal women and men with osteoporosis at high fracture risk, and for glucocorticoid-induced osteoporosis.
The boxed warning was removed in November 2020, along with the two-year lifetime treatment limitation. The original warning came from osteosarcoma in rats given high doses for most of their lifespan — a model with known poor predictive value for human bone tumours. Two large claims-based cohort studies found no excess osteosarcoma in treated patients.[1] Contraindications in people whose baseline osteosarcoma risk is already raised remain in force.
Sold only on prescription. Any offer of unlicensed "research-grade teriparatide" is either diverted licensed product or is not teriparatide.
Regulatory and trial claims re-checked against primary sources on 16 August 2026. Checked: boxed warning and 2-year cap removal, November 2020. Approvals, trial readouts and compounding decisions move faster than anything else on this page — a date here means someone looked, not that nothing has changed since.
Peptide hormones and growth factors are addressed under the WADA Prohibited List. Verify teriparatide against the current list before use in a tested athlete.
Links resolve to PubMed records, trial registries, publisher pages or primary documents. Where a body of work rather than a single paper is cited, the link opens a PubMed query so the full result set — including newer papers than this page — can be reviewed. Verify every claim against the primary source before relying on it.
For educational and research reference only. Nothing on this site is medical advice, a recommendation, or an instruction to administer any substance to a human being. Every figure on this page is a record of what has been reported, not a recommendation. Full disclaimer.
