Abaloparatide
Also known as: Tymlos, Eladynos, BA058, BIM-44058, PTHrP(1-34) analog
PTHrP Analog | Anabolic Bone-Building Agent
Overview
Abaloparatide is an FDA-approved anabolic bone-building agent and synthetic analog of parathyroid hormone-related protein (PTHrP). It selectively activates the PTH1 receptor to stimulate new bone formation while minimizing bone resorption. In the phase III ACTIVE trial, abaloparatide showed superior BMD increases at the hip compared to teriparatide, with substantial fracture risk reduction. It was approved in the US in 2017 and EU in 2022 for postmenopausal women and men with osteoporosis at high fracture risk.
Key benefits
- FDA-approved for osteoporosis treatment
- Actively builds new bone (anabolic mechanism)
- Superior hip BMD gains vs teriparatide in trials
- Reduces vertebral fracture risk significantly
- Reduces nonvertebral fracture risk
- Lower hypercalcemia risk than teriparatide
- Works through selective PTH1R activation
- Benefits seen within 6 months
Mechanism of action
Abaloparatide works through selective activation of the parathyroid hormone 1 receptor (PTH1R), a G protein-coupled receptor expressed on osteoblasts and osteocytes. It preferentially binds to the RG (relaxed, G-protein-coupled) conformational state of PTH1R, which elicits a transient downstream cyclic AMP signaling response favoring anabolic bone formation over resorption. This selective binding pattern produces more bone-building activity with less hypercalcemic effect compared to native PTH. The result is increased cortical and trabecular bone volume, density, and improved microarchitecture.
Molecular data
- Type
- Synthetic PTHrP analog
- Half-life
- ~1.7 hours
Sequence
C174H299N56O49 - 41% homology to PTH(1-34), 76% homology to PTHrP(1-34)
Indications
What the research community uses this compound for, with self-reported effectiveness.
Osteoporosis (FDA-Approved)
Bone Health Research
Dosing protocols
Common protocols by delivery method. Adjust the curve below to model accumulation in your own cycle.
Delivery method
| Protocol | Dose | Frequency | Duration |
|---|---|---|---|
| — | 80 mcg | Once daily | — |
Safety
Reported adverse effects, contraindications, and what to monitor on cycle.
Common side effects
- Hypercalciuria (high calcium in urine)
- Dizziness
- Nausea
- Headache
- Palpitations
- Fatigue
- Upper abdominal pain
- Vertigo
- Injection site reactions
Rare side effects
- Hypercalcemia
- Orthostatic hypotension
- Osteosarcoma (theoretical - seen in rodent studies at high doses)
Contraindications
- Paget's disease of bone
- Prior external beam or implant radiation therapy to skeleton
- Bone metastases or history of skeletal malignancies
- Metabolic bone diseases other than osteoporosis
- Pre-existing hypercalcemia
- Pregnancy or nursing
- Cumulative use exceeding 2 years lifetime
Monitoring
- Serum calcium levels
- Urine calcium (hypercalciuria common)
- Bone mineral density testing
- Treatment limited to 2 years maximum lifetime
- Follow with antiresorptive therapy to maintain gains