Abaloparatide

Abaloparatide (brand name Tymlos) is a prescription medicine for osteoporosis — a condition where bones become thin and break easily. Most osteoporosis drugs work by slowing down the breakdown of bone. Abaloparatide is one of the few that works the other way round: it tells the body to build new bone. It is a lab-made version of a natural human hormone called PTHrP, it is FDA-approved, and it is given as a daily injection under the skin.

Abaloparatide has been studied in postmenopausal women with osteoporosis who were at high risk of breaking a bone. The main trial was large and well-designed — about 2,500 women, 18 months, with a placebo group and a group taking teriparatide, the older drug in the same family. Fewer new spine fractures happened in the women taking abaloparatide than in those on placebo, and bone density rose. A separate look at the same trial found it briefly raised heart rate after each injection, settling within a few hours. The honest part: the fracture evidence comes from a trial in postmenopausal women, so that is where it sits. The label also covers men, but that indication is about increasing bone density rather than reducing fractures. And it is a daily injection rather than a pill.

FDA-approved prescription drug (Tymlos). A synthetic analog of parathyroid hormone-related protein (PTHrP), approved for osteoporosis at high fracture risk. This is a genuine prescription medicine, distinct from the research-only peptides elsewhere in this library, and the closest relative in this library is `teriparatide` — the two were compared head-to-head in the same pivotal trial.[¹] Exact approved indications and populations are set by current FDA labeling. WADA status: abaloparatide is not named on the 2026 WADA Prohibited List, and no parathyroid-hormone drug class appears on that list (verified directly against the 2026 list text, 2026-08-04). Because it holds regulatory approval for human therapeutic use, S0 (Non-Approved Substances) does not capture it. The S2.3 growth-factor clause also does not reach it — that clause is limited verbatim to growth factors affecting "muscle, tendon or ligament", and abaloparatide's action is on bone. Same position as teriparatide already in this library. Athletes should verify with their anti-doping organization. Not DEA-scheduled (prescription, non-controlled).

Abaloparatide is a prescription drug and should only be used under a clinician's care. In the pivotal trial it briefly raised heart rate after each dose and slightly lowered blood pressure, with serious cardiac events no more common than placebo. It caused less high blood calcium than teriparatide, the comparison drug. It is not named on the WADA Prohibited List and, being an approved medicine, is not captured by the S0 non-approved-substances category — but athletes should verify with their anti-doping organization. VialWise is a research and educational reference, not medical advice — consult a licensed professional.

⚠️ This is an approved prescription medicine, not a research peptide. Abaloparatide is dispensed by a pharmacy under prescription and used under clinical supervision. The reconstitution and self-dosing workflows used elsewhere in this library do not apply. Information here is informational, not medical advice.

⚠️ The fracture evidence is in postmenopausal women. The pivotal trial enrolled 2,463 postmenopausal women with osteoporosis.[¹] That is where the fracture-outcome evidence sits. The label now also covers men with osteoporosis at high risk for fracture, but that indication is worded to *increase bone density* rather than to reduce fractures — the endpoints are not the same, and nothing in this entry supports extrapolating the fracture-outcome result beyond the population it was measured in.

⚠️ A note on what this entry does not tell you. The published abstract of the pivotal trial renders its fracture-rate table as "[table: see text]", so the exact percentage fracture rates are not available from it. This entry therefore states the direction of the findings as the authors wrote them, and deliberately does not quote specific fracture percentages. If you need those numbers, read the full paper.[¹]

Abaloparatide is a synthetic 34-amino-acid analog of parathyroid hormone-related protein (PTHrP), marketed as Tymlos.

Mechanism. It is described as a selective activator of the parathyroid hormone type 1 receptor (PTH1R).[¹] Activating that receptor intermittently — once daily rather than continuously — stimulates bone formation rather than bone loss, which is what makes this class *anabolic* rather than *antiresorptive*. A bone-biopsy study confirmed the mechanism directly: after 3 months daily, bone formation rate increased on all four bone envelopes (cancellous, endocortical, intracortical, periosteal), reflecting stimulation of both remodeling-based and modeling-based bone formation.[³]

Relationship to teriparatide. `teriparatide` (already in this library) is PTH(1-34); abaloparatide is PTHrP(1-34). Different parent hormones, same receptor. They were compared directly in the pivotal trial, which included an open-label teriparatide arm.[¹]

Evidence quality. This is one of the better-evidenced compounds in this library:

- ACTIVE, the registration trial, was a Phase 3, double-blind, randomized controlled trial run March 2011–October 2014 at 28 sites in 10 countries.[¹] It enrolled 2,463 postmenopausal women (mean age 69, range 49–86) with low bone mineral density plus fracture history; 1,901 completed. Participants were randomized to daily subcutaneous placebo (n=821), abaloparatide (n=824), or open-label teriparatide (n=818) for 18 months.[¹] The authors report that new morphometric vertebral fractures occurred less frequently in the active treatment groups than placebo, that the Kaplan-Meier estimated event rate for nonvertebral fracture was lower with abaloparatide than placebo, and that BMD increases were greater with abaloparatide than placebo at all measured sites (all P <.001).[¹] Incidence of hypercalcemia was lower with abaloparatide (3.4%) than teriparatide (6.4%) — risk difference −2.96 (95% CI −5.12 to −0.87), P =.006.[¹] - A cardiovascular safety analysis pooled ACTIVE, its extension ACTIVExtend, and a pharmacology study in 55 healthy adults.[²] Both abaloparatide and teriparatide transiently raised heart rate: mean change from pre-dose to 1 hour post-dose was +7.9 bpm (SD 8.5) for abaloparatide, +5.3 for teriparatide, and +1.2 for placebo, with the same pattern at later visits.[²] In healthy volunteers the rise resolved within 4 hours.[²] Blood pressure fell slightly (−2.7/−3.6 mmHg for abaloparatide). Serious cardiac adverse events were similar across groups (0.9%–1.0%).[²] - A bone histomorphometry study took transiliac biopsies from 23 postmenopausal women after 3 months of treatment and documented increased bone formation across all four envelopes.[³] ⚠️ This one is open-label and single-arm — it demonstrates mechanism, not comparative efficacy.

Note the authors' own caution. The ACTIVE authors close by stating that further research is needed to understand the clinical importance of the risk difference, the risks and benefits of treatment, and the efficacy of abaloparatide versus other osteoporosis treatments.[¹] That is unusually candid for a registration trial and is worth carrying forward.

Regulatory status (US). FDA-approved as Tymlos for two populations: postmenopausal women with osteoporosis at high risk for fracture, where the label states it reduces the risk of vertebral and nonvertebral fractures; and men with osteoporosis at high risk for fracture, where the indication is to *increase bone density*. The label defines high risk as a history of osteoporotic fracture or multiple risk factors for fracture, and both indications also cover patients who have failed or are intolerant to other available osteoporosis therapy. Note the endpoints differ between the two: fracture-risk reduction is claimed for women, bone-density increase for men. Not DEA-scheduled.

Regulatory status (sport — WADA). Abaloparatide is not named on the 2026 WADA Prohibited List, and no parathyroid-hormone class appears anywhere on it (checked directly against the list text, 2026-08-04). S0 captures only substances with no current approval by any regulatory health authority — abaloparatide is approved, so S0 does not reach it. S2.3 (growth factors) was also checked: its catch-all is limited verbatim to growth factors affecting "muscle, tendon or ligament" protein synthesis/degradation, vascularization, energy utilization, regenerative capacity or fiber type switching — bone is not among those tissues. This matches the position already recorded for `teriparatide`. Verify with your National Anti-Doping Organization.

Commonly reported

• Transient heart-rate increase after each dose — mean +7.9 bpm at 1 hour, resolving within 4 hours in healthy volunteers.[²] Occurred with teriparatide too (+5.3 bpm), so it is a class effect rather than unique to abaloparatide.[²]
• Small blood-pressure decrease — mean −2.7/−3.6 mmHg at 1 hour post-dose.[²]
• Hypercalcemia (raised blood calcium) in 3.4% — notably *lower* than teriparatide's 6.4%, P =.006.[¹]

Serious

• Serious cardiac adverse events were similar across all three groups (0.9%–1.0%).[²] In a post hoc analysis, time to first major adverse cardiovascular event plus heart failure was actually *longer* with abaloparatide (P =.02) and teriparatide (P =.04) than placebo.[²] ⚠️ Read that cautiously — it is post hoc, meaning the analysis was chosen after seeing the data, and it does not establish a protective effect.

This is a prescription medicine. Use outside a prescribed, clinically supervised context is outside everything the evidence base covers.

Conditions predisposing to hypercalcemia — abaloparatide raised blood calcium in 3.4% of trial participants.[¹] Consult current labeling for the specific contraindications and monitoring.

Cardiac conditions where a transient heart-rate rise matters — the effect is real, dose-linked, and repeated with every injection.[²] Serious cardiac events were not increased in the trial, but the tachycardia signal is documented.

Anabolic bone agents carry class-specific labeling history. `teriparatide` in this library records that its osteosarcoma boxed warning was removed by FDA in 2020. Treatment-duration limits and any residual cautions for abaloparatide are set by current labeling and are not asserted here.

Pregnancy and lactation — the pivotal trial enrolled postmenopausal women; not addressed by the sources here. Refer to current labeling.

Pediatric use — not studied in the trials cited here.

Regulatory note (sport): not named on the 2026 WADA Prohibited List, not captured by S0 (approved medicine), and not captured by S2.3 (that clause covers muscle, tendon, and ligament only). Verify with your anti-doping organization.

Not DEA-scheduled.

Peptide

A short chain of amino acids, the building blocks of proteins. Many compounds in this library are peptides.

Osteoporosis

A condition where bone becomes less dense and more fragile, so bones break more easily — sometimes from a minor fall or even normal movement.

Anabolic (in bone)

Bone-building. Most osteoporosis drugs are the opposite — they slow bone loss. Abaloparatide is in the smaller group that stimulates new bone formation.

PTHrP

Parathyroid hormone-related protein, a natural signaling protein involved in bone and calcium regulation. Abaloparatide is a synthetic version of part of it.

Bone mineral density (BMD)

A measure of how much mineral is packed into bone, used to diagnose osteoporosis and to track whether treatment is working.

1. Miller PD, Hattersley G, Riis BJ, Williams GC, Lau E, Russo LA, Alexandersen P, Zerbini CAF, Hu MY, Harris AG, Fitzpatrick LA, Cosman F, Christiansen C. (2016). Effect of Abaloparatide vs Placebo on New Vertebral Fractures in Postmenopausal Women With Osteoporosis: A Randomized Clinical Trial. JAMA, 316(7):722–733.(PMID 27533157 · NCT01343004)
2. Cosman F, Peterson LR, Towler DA, Mitlak B, Wang Y, Cummings SR. (2020). Cardiovascular Safety of Abaloparatide in Postmenopausal Women With Osteoporosis: Analysis From the ACTIVE Phase 3 Trial. The Journal of Clinical Endocrinology and Metabolism, 105(11):3384–3395.(PMID 32658264 · NCT01343004)
3. Dempster DW, Zhou H, Rao SD, Recknor C, Miller PD, Leder BZ, Annett M, Ominsky MS, Mitlak BH. (2021). Early Effects of Abaloparatide on Bone Formation and Resorption Indices in Postmenopausal Women With Osteoporosis. Journal of Bone and Mineral Research, 36(4):644–653.(PMID 33434314)

• Teriparatide — discussed together in this entry's stacks section