EB613 (Oral PTH 1-34 Tablet)
Also known as: Oral teriparatide tablet, Entera oral PTH, Oral anabolic bone tablet
Overview
EB613 is an oral tablet formulation of recombinant human parathyroid hormone (PTH 1-34) being developed by Entera Bio for postmenopausal osteoporosis. The active molecule is identical to teriparatide (Forteo) — a 34-amino-acid N-terminal fragment of human PTH that, when delivered in pulsatile rather than continuous fashion, acts as an anabolic bone-forming agent. The novelty of EB613 is the delivery system: a proprietary excipient stack engineered to protect the peptide through stomach acid and pancreatic proteases and to assist transcellular absorption across the intestinal epithelium. If approved, EB613 would be the first oral anabolic bone drug. As of May 2026, Entera has submitted a streamlined Phase 3 protocol to the FDA under a 505(b)(2) IND, with FDA feedback described by the company as imminent. The Phase 3 design is a multinational, randomized, double-blind, placebo-controlled study of approximately 750 postmenopausal women with osteoporosis, with the primary endpoint being percent change in total hip bone mineral density at month 12.
Mechanism of Action
Same target as teriparatide: PTH 1-34 binds PTH receptor 1 (PTH1R), a class B GPCR on osteoblasts, osteoclasts, and renal tubular cells. Intermittent pulsatile activation of PTH1R on osteoblasts stimulates new bone formation by reducing osteoblast apoptosis, activating quiescent lining cells, stimulating osteoblast precursor differentiation, and inhibiting the Wnt signaling inhibitors sclerostin and DKK1. The pharmacological challenge for an oral formulation is achieving a peak exposure profile that mimics the pulsatile injection — high enough and brief enough to produce the anabolic rather than catabolic response.
Potential Benefits
- Oral administration (tablet) instead of daily subcutaneous injection
- Targets the same anabolic biology as teriparatide
- Phase 2 data showed dose-dependent rise in lumbar spine BMD and anabolic biomarker shifts (P1NP up, CTX down)
- Patient adherence advantage over injectable anabolic therapy
- Potential to expand the eligible-but-declining population of patients refusing injections
Dosage Protocols
The following reflects doses used in published research studies. This is not medical advice. Consult a qualified healthcare professional.
| Beginner | Investigational only — not available outside trial |
| Intermediate | Investigational only — not available outside trial |
| Advanced | Investigational only — not available outside trial |
| Cycle Duration | Phase 3 trial duration is 12 months primary endpoint plus 24 months extension |
EB613 is not commercially available. Patients eligible for anabolic osteoporosis therapy should consult their physician about approved options (teriparatide, abaloparatide, romosozumab).
Use our Reconstitution Calculator to determine exact syringe units for your protocol.
Routes of Administration
Oral (tablet) Not publicly disclosed; the Phase 1 bridging study targeted exposure comparable to Forteo subcutaneous 20 mcg
Tablet formulated with proprietary excipient stack to protect peptide through gastric and pancreatic protease activity and assist transcellular intestinal absorption.
Read our full Routes of Administration Guide for detailed comparison of all delivery methods.
Reconstitution
| Storage | Investigational; storage conditions per trial protocol |
|---|
No reconstitution required. Oral tablet.
Need exact syringe measurements?
Amino Acid Sequence
Same as teriparatide: Ser-Val-Ser-Glu-Ile-Gln-Leu-Met-His-Asn-Leu-Gly-Lys-His-Leu-Asn-Ser-Met-Glu-Arg-Val-Glu-Trp-Leu-Arg-Lys-Lys-Leu-Gln-Asp-Val-His-Asn-Phe (34 AA)
Side Effects & Safety
- Expected to inherit teriparatide adverse-effect profile pending Phase 3 data
- Nausea, dizziness, leg cramps (teriparatide class)
- Transient hypercalcemia (teriparatide class)
- Orthostatic hypotension (teriparatide class)
- GI tolerability of the oral formulation specifically remains to be characterized in pivotal trial
- Residual label flag for osteosarcoma risk inherited from teriparatide (rodent data; not confirmed in human surveillance)
Safety & Contraindications
This information is for educational purposes only. Consult a qualified healthcare provider before using any peptide.
Investigational only
FDA Safety Information
Investigational. Safety profile expected to mirror teriparatide pending Phase 3 readout. The residual osteosarcoma label language that applies to teriparatide is expected to apply to EB613.
Pharmacokinetics
| Half-Life | PTH 1-34 plasma half-life is approximately 1 hour; EB613 PK profile targets comparable Cmax and AUC to subcutaneous Forteo |
|---|---|
| Storage | Per clinical trial protocol |
Synergistic Compounds
The following compounds have been studied alongside EB613 (Oral PTH 1-34 Tablet) for potential complementary or synergistic effects:
Learn More
References & Further Reading
Latest News & Research
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