At a Glance
| Feature | Detail |
|---|---|
| Name / structure | Abaloparatide; 34-amino-acid synthetic analogue of human parathyroid hormone-related protein, PTHrP(1-34) |
| Origin | Developed by Radius Health; approved as Tymlos (US) and Eladynos (EU) |
| Mechanism | Selective activator of the PTH type 1 receptor (PTH1R), favouring a transient signal that stimulates bone formation over resorption |
| Used for | Postmenopausal osteoporosis at high fracture risk; osteoporosis in men at high fracture risk (US) |
| Route | Subcutaneous injection (pre-filled pen), lower abdomen |
| Typical dose | 80 mcg once daily |
| Evidence level | Strong: phase 3 randomised trial with fracture endpoints (ACTIVE, n = 2,463), an extension study, a randomised trial in men and meta-analyses |
| Regulatory status | FDA approved (Tymlos, 2017 for women, later extended to men); EU authorised December 2022 (Eladynos); WADA 2026: not named, approved medicine |
Abaloparatide belongs in this library for a simple reason: people searching for “peptides for bone” deserve to know that a bone-building peptide exists that has been tested properly. It is not a grey-market compound. It is a prescription medicine with fracture outcomes from thousands of patients, a label and a known list of side effects.
The verdict is clear for its approved use. For a postmenopausal woman with osteoporosis and a high fracture risk, especially after a vertebral fracture, an anabolic drug first and an antiresorptive second is now a mainstream strategy, and abaloparatide is one of the anabolic options. Using it outside that context, for example as a “longevity” or “recovery” peptide in people without osteoporosis, has no trial support.
How it works
Parathyroid hormone (PTH) and PTH-related protein both act on the PTH1 receptor. Continuously high PTH, as in hyperparathyroidism, dissolves bone. Short daily pulses do the opposite: they activate osteoblasts and lay down new bone faster than it is removed. This “anabolic window” is the basis of both teriparatide and abaloparatide.
Abaloparatide was designed to favour a receptor conformation that gives a shorter, more transient signal. The idea, supported by its lower rate of hypercalcaemia compared with teriparatide [1], is a strong bone-forming stimulus with less calcium mobilisation. The drug adds new bone rather than only slowing loss, and that new bone needs protecting afterwards, which is why the course is followed by an antiresorptive drug [2].
What the evidence shows
Postmenopausal women
| Study | Design | n | Dose | Main finding |
|---|---|---|---|---|
| ACTIVE, Miller 2016 [1] | Phase 3, double-blind, placebo-controlled; open-label teriparatide arm | 2,463 | 80 mcg SC daily vs placebo vs teriparatide 20 mcg, 18 months | New vertebral fractures 0.6 % vs 4.2 % on placebo (relative risk reduction 86 %); non-vertebral fractures reduced by 43 %; hypercalcaemia 3.4 % vs 6.4 % with teriparatide [1][7] |
| ACTIVExtend, Bone 2018 [2] | Extension: alendronate for 24 months after ACTIVE | 1,139 | Alendronate after abaloparatide or placebo | Over 43 months, new vertebral fractures 0.9 % vs 5.6 % (84 % relative reduction); no hip fractures after abaloparatide vs five after placebo |
| Leder 2020 [6] | Post hoc comparison of the ACTIVE and ACTIVExtend periods | 1,139 | As above | Compared vertebral fracture reduction during abaloparatide with that during alendronate |
| Beaudart 2025 [5] | Systematic review and network meta-analysis, 11 RCTs and 6 real-world studies | 17 studies | PTH1R agonists vs other treatments | Abaloparatide and teriparatide both reduced vertebral and non-vertebral fractures; abaloparatide had an advantage over teriparatide for non-vertebral (OR 0.87) and hip fractures (OR 0.81); no increased cardiovascular risk |
Men
The ATOM trial randomised 228 men aged 40 to 85 with osteoporosis 2:1 to abaloparatide 80 mcg or placebo for 12 months. Lumbar spine bone density rose 8.5 % vs 1.2 %, total hip 2.1 % vs 0.0 % and femoral neck 3.0 % vs 0.2 % [3]. The trial measured bone density, not fractures.
Limits
ACTIVE compared abaloparatide with placebo; the teriparatide arm was open-label and not powered for a head-to-head fracture comparison. Anabolic therapy is limited in duration, and the long-term benefit depends on what follows it.
Who it is for, and the order of drugs
The label defines high fracture risk as a history of osteoporotic fracture or multiple risk factors for fracture, or failure of or intolerance to other therapy [7]. In practice that means, for example, a woman with a recent vertebral fracture, a very low T-score, or fractures despite a bisphosphonate. For a woman with mild osteopenia and no fractures, an anabolic drug is rarely the first choice.
The order of drugs matters as much as the choice. ACTIVExtend showed that the gains made on abaloparatide were kept and extended when alendronate followed [2]. The reverse direction can backfire. In the DATA-Switch study with teriparatide, a drug of the same class, women who switched from teriparatide to denosumab kept gaining spine density, while switching from denosumab to teriparatide led to progressive or transient bone loss [9]. The same caution is generally applied to abaloparatide: an anabolic course works best early in the sequence, and stopping denosumab needs its own plan because bone loss after stopping it can be rapid.
Practical consequences: before starting, a DXA scan, a vertebral fracture assessment, blood calcium, vitamin D, kidney function and a review of secondary causes; during treatment, attention to calcium in blood and urine if symptoms or risk factors suggest it; at the end, a planned switch to an antiresorptive rather than simply stopping.
Dosing
For informational purposes only — this summarises doses used in research and practice; it is not a prescription or individual medical advice.
| Goal | Dose | Route | Frequency / timing | Cycle length | Basis |
|---|---|---|---|---|---|
| Postmenopausal osteoporosis, high fracture risk | 80 mcg | SC, periumbilical abdomen | Once daily at about the same time; first doses where the patient can sit or lie down | US: no more than 2 years per lifetime. EU: maximum 18 months | Label (Tymlos, Eladynos) [7][8]; Trial [1] |
| Osteoporosis in men, high fracture risk (US) | 80 mcg | SC | Once daily | 12 months studied; label limit as above | Label [7]; Trial [3] |
| Consolidation after the anabolic course | Antiresorptive, e.g. alendronate 70 mg | Oral | Weekly | 24 months studied | Trial [2] |
| Supporting nutrition | Calcium and vitamin D | Oral | Daily if dietary intake is inadequate | During treatment | Label [7] |
This is a label-based medicine, so there is no grey-market protocol worth repeating; good practice is the label. Two practical points from it: rotate the injection site daily, and give the first several doses where the patient can sit or lie down, because orthostatic hypotension typically appears within 4 hours of an injection [7]. Timing (for example in the evening) is worth discussing with the prescriber if dizziness is a problem.
For general injection technique, see the peptide injection guide. The pen comes with its own instructions, which take precedence.
What people report: what works and what doesn’t
Here the community is patients on a prescription drug, mainly in drug-review forums. These reports are self-selected and skew negative.
Reported to work
- Rising bone density on follow-up DXA scans, which is what the trials predict, and often the reason people persist through early side effects.
- Side effects that settle after the first weeks for many users.
Mixed or unclear
- Evening dosing: several reviewers report that injecting at night helps with dizziness and a racing heart (Drugs.com reviews).
- Cost and insurance coverage decide for many whether they complete the course.
Reported not to work, or disappointing
- A racing or pounding heart for minutes after the injection, dizziness or vertigo, and fatigue or brain fog that some describe as lasting through the day (Drugs.com reviews). On Drugs.com, about a hundred reviews average 4.5 out of 10, which says more about who writes reviews than about the drug’s effect on fractures.
- In the trials these effects were real but led few patients to stop [1].
What a further trial would need to show: head-to-head fracture superiority over teriparatide and romosozumab, and the best sequence of drugs after an anabolic course.
Safety and side effects
From the US label [7]:
- Most common in women (at least 2 %): hypercalciuria, dizziness, nausea, headache, palpitations, fatigue, upper abdominal pain and vertigo. In men, injection-site reactions and dizziness lead the list.
- Orthostatic hypotension, typically within 4 hours of injection.
- A dose-dependent rise in heart rate within 15 minutes of injection that resolves in about 6 hours.
- Hypercalcaemia: avoid in pre-existing hypercalcaemia or primary hyperparathyroidism. Hypercalciuria and kidney stones: monitor urine calcium where suspected.
- Serious hypersensitivity, including anaphylaxis, has been reported; severe hypersensitivity is a contraindication.
- Anti-drug antibodies develop in a proportion of patients (25 % of men over 12 months).
Osteosarcoma: in 2-year rat studies, abaloparatide and teriparatide both produced bone tumours in a dose-dependent way [4]. Human observational data have not shown an increased risk with PTH-type drugs, and the US label no longer carries a boxed warning, but it still advises avoiding use in people with open growth plates, Paget’s disease or other metabolic bone disease, bone metastases or a history of skeletal cancer, prior radiation to the skeleton, or hereditary conditions that predispose to osteosarcoma.
Abaloparatide is not for children or for use in pregnancy. It does not inhibit or induce cytochrome P450 enzymes. Before starting, secondary causes of osteoporosis (vitamin D deficiency, hyperparathyroidism, coeliac disease, myeloma, medications) need to be ruled out.
Legal and regulatory status
- United States. FDA approved as Tymlos (80 mcg/day pen) for postmenopausal women with osteoporosis at high fracture risk, later extended to men with osteoporosis at high fracture risk. Prescription only. The label states that use for more than 2 years in a lifetime is not recommended [7].
- EU and Germany. Authorised EU-wide as Eladynos in December 2022 for postmenopausal osteoporosis at increased fracture risk, with a maximum treatment duration of 18 months; prescription only [8].
- Sport. Abaloparatide is not named on the WADA 2026 Prohibited List, and as an approved medicine it does not fall under S0. Athletes should confirm with their national anti-doping organisation before use.
How it fits
| Abaloparatide | Teriparatide | Romosozumab | Bisphosphonates / denosumab | |
|---|---|---|---|---|
| Type | PTHrP analogue (anabolic) | PTH(1-34) (anabolic) | Anti-sclerostin antibody (anabolic and antiresorptive) | Antiresorptive |
| Dosing | 80 mcg SC daily | 20 mcg SC daily | Monthly SC injections | Oral weekly or IV yearly; denosumab SC every 6 months |
| Typical course | 18–24 months | Up to 24 months | 12 months | Long-term |
| Fracture data | Vertebral and non-vertebral (ACTIVE) | Vertebral and non-vertebral | Vertebral and clinical | Extensive |
Among the peptides in this library, abaloparatide is the outlier: fully approved, studied in thousands of people, with fracture endpoints. Non-drug measures matter alongside it, and the site’s article on PEMF therapy for osteoporosis compares physical approaches with the drug data, including teriparatide.
Related Articles
- PEMF Therapy for Osteoporosis
- Collagen Peptides: Types, Benefits and Evidence
- Peptide Injection Guide
- Peptides and WADA Anti-Doping Rules
Frequently asked questions
What is abaloparatide used for?
It is approved for postmenopausal women with osteoporosis at high risk of fracture, and in the US also to increase bone density in men with osteoporosis at high risk of fracture. It is an anabolic (bone-building) drug, unlike bisphosphonates and denosumab, which mainly slow bone loss.
What is the dose of abaloparatide?
80 mcg injected under the skin of the lower abdomen once a day, with calcium and vitamin D if dietary intake is low. The first doses should be taken where the patient can sit or lie down, because of the risk of a drop in blood pressure.
How long can you take abaloparatide?
The US label says use for more than 2 years in a lifetime is not recommended; the EU label (Eladynos) sets a maximum of 18 months. Afterwards, an antiresorptive drug such as a bisphosphonate is normally started to keep the gains.
Is abaloparatide better than teriparatide?
In ACTIVE, both reduced vertebral fractures versus placebo, and hypercalcaemia was less common with abaloparatide (3.4% vs 6.4%). A 2025 network meta-analysis found an advantage for abaloparatide for non-vertebral and hip fractures. A head-to-head trial designed to prove superiority has not been done.
Does abaloparatide cause bone cancer?
In lifelong rat studies, abaloparatide and teriparatide both caused osteosarcoma in a dose-dependent way. Observational studies in humans have not shown an increased risk with PTH-type drugs, but the label still advises avoiding it in people at higher baseline risk, such as those with Paget's disease, prior skeletal radiation or bone metastases.
References
- Miller PD, Hattersley G, Riis BJ, et al. Effect of Abaloparatide vs Placebo on New Vertebral Fractures in Postmenopausal Women With Osteoporosis: A Randomized Clinical Trial. JAMA. 2016. PMID: 27533157. https://pubmed.ncbi.nlm.nih.gov/27533157/
- Bone HG, Cosman F, Miller PD, et al. ACTIVExtend: 24 Months of Alendronate After 18 Months of Abaloparatide or Placebo for Postmenopausal Osteoporosis. J Clin Endocrinol Metab. 2018. PMID: 29800372. https://pubmed.ncbi.nlm.nih.gov/29800372/
- Czerwinski E, Cardona J, Plebanski R, et al. The Efficacy and Safety of Abaloparatide-SC in Men With Osteoporosis: A Randomized Clinical Trial. J Bone Miner Res. 2022. PMID: 36190391. https://pubmed.ncbi.nlm.nih.gov/36190391/
- Jolette J, Attalla B, Varela A, et al. Comparing the incidence of bone tumors in rats chronically exposed to the selective PTH type 1 receptor agonist abaloparatide or PTH(1-34). Regul Toxicol Pharmacol. 2017. PMID: 28389324. https://pubmed.ncbi.nlm.nih.gov/28389324/
- Beaudart C, Veronese N, Douxfils J, et al. PTH1 receptor agonists for fracture risk: a systematic review and network meta-analysis. Osteoporos Int. 2025. PMID: 40047881. https://pubmed.ncbi.nlm.nih.gov/40047881/
- Leder BZ, Mitlak B, Hu MY, et al. Effect of Abaloparatide vs Alendronate on Fracture Risk Reduction in Postmenopausal Women With Osteoporosis. J Clin Endocrinol Metab. 2020. PMID: 31674644. https://pubmed.ncbi.nlm.nih.gov/31674644/
- TYMLOS (abaloparatide) injection. US Prescribing Information, via openFDA (label effective August 2026). https://api.fda.gov/drug/label.json?search=openfda.generic_name:abaloparatide
- European Medicines Agency. Eladynos (abaloparatide): European public assessment report. https://www.ema.europa.eu/en/medicines/human/EPAR/eladynos
- Leder BZ, Tsai JN, Uihlein AV, et al. Denosumab and teriparatide transitions in postmenopausal osteoporosis (the DATA-Switch study): extension of a randomised controlled trial. Lancet. 2015. PMID: 26144908. https://pubmed.ncbi.nlm.nih.gov/26144908/
Disclaimer: This article is for information and education only and is not a prescription or individual medical advice. Abaloparatide is a prescription medicine; decisions about osteoporosis treatment belong with your physician.
