Atosiban
Atosiban is an oxytocin receptor antagonist. Atosiban is a modified oxytocin analog that competitively antagonises the oxytocin receptor on uterine myometrium and decidua, reducing oxytocin-driven intracellular calcium release and prostaglandin production and thereby suppressing uterine contractions. Its receptor selectivity gives it a narrower systemic side-effect profile than non-selective tocolytics such as beta agonists.
For research use only.
Key Facts
- CAS
- 90779-69-4
- Molecular Weight (MW)
- 994.2 g/mol
- Half-life
- —
- FDA status
- Not Approved
- Administration Route
- intravenous
- Frequency
- —
- Last updated
- Aug 30, 2026
- Reviewed
- Aug 30, 2026
Research summary
Oxytocin receptor antagonist used in Europe and elsewhere as a tocolytic to delay imminent preterm birth. It is not approved by the FDA in the United States.
Peptide Library's Atosiban profile summarises 5 cited studies listed in the Science section, the compound's regulatory status, and research-protocol parameters reported for it. It is a research reference, not medical advice.
Protocol
- Dosage Range
- —
- Frequency
- —
- Cycle
- —
- Administration Route
- intravenous
- Reconstitution Guide
- —
Not yet checked against primary sources
These figures are compiled from earlier reference material. They have not been verified against FDA labelling, registered trials or published literature, no citation is attached to them, and none of them is a recommended dose. Atosiban is queued for dosage evidence review.
Compare reported doses across the whole librarySequence & molecular data
| Molecular formula | C43H67N11O12S2 |
|---|---|
| Molecular weight | 994.2 g/mol |
| CAS number | 90779-69-4 |
| PubChem CID | 5311010 |
| FDA UNII | 081D12SI0Z |
| ChEMBL | CHEMBL382301 |
| DrugBank | DB09059 |
Identifiers link to the public PubChem, FDA Substance Registration (UNII), ChEMBL and DrugBank records for the same entity.
Science
Mechanism of Action
Atosiban is a modified oxytocin analog that competitively antagonises the oxytocin receptor on uterine myometrium and decidua, reducing oxytocin-driven intracellular calcium release and prostaglandin production and thereby suppressing uterine contractions. Its receptor selectivity gives it a narrower systemic side-effect profile than non-selective tocolytics such as beta agonists.
Studies
- Efficacy of atosiban for repeated embryo implantation failure: A systematic review and meta-analysis
- Randomised, triple-blind, placebo-controlled trial of atosiban in women with previous embryo implantation failure and abnormal uterine contractions undergoing single blastocyst-stage embryo transfer: a study protocol
- Atosiban versus placebo for threatened preterm birth (APOSTEL 8): a multicentre, randomised controlled trial
- Interventions to optimize embryo transfer in women undergoing assisted conception: a comprehensive systematic review and meta-analyses
- The safety of tocolytics used for the inhibition of preterm labour
Regulatory & research status
Atosiban is not an FDA-approved product. It is sold for laboratory research and has no approved medical use.
| FDA status | Not Approved |
|---|---|
| Research status | Research-only compound; no approval pathway listed |
| Availability | Prescription-Only |
| WADA (sport) | Unknown / Not Listed |
| Library classification | Clinical Trial |
Benefits
—
Potential Side Effects
No side effects listed yet for this entry.
Storage & stability
Lyophilized (freeze-dried) peptide powder is far more stable than the reconstituted solution. Keep sealed vials cold, dry and away from light; long-term storage is typically frozen, with short-term refrigeration for vials in use.
Once reconstituted in bacteriostatic water, keep the solution refrigerated, avoid repeated freeze–thaw cycles and agitation, and label the vial with the reconstitution date and concentration. Discard any solution that turns cloudy or shows particulates.
Degradation rates differ by sequence: peptides containing methionine, cysteine, asparagine or glutamine are more prone to oxidation and deamidation, so shelf life after reconstitution is compound-specific rather than universal.
Read the full guide: how to store peptides before and after reconstitution →
Source: Manning MC, Chou DK, Murphy BM, Payne RW, Katayama DS. Stability of protein pharmaceuticals: an update. Pharm Res. 2010;27(4):544–575. (PMID 20143256). General guidance for research handling; not product-specific instructions.
Atosiban: frequently asked questions
What is Atosiban?
Oxytocin receptor antagonist used in Europe and elsewhere as a tocolytic to delay imminent preterm birth. It is not approved by the FDA in the United States.
How does Atosiban work?
Atosiban is a modified oxytocin analog that competitively antagonises the oxytocin receptor on uterine myometrium and decidua, reducing oxytocin-driven intracellular calcium release and prostaglandin production and thereby suppressing uterine contractions. Its receptor selectivity gives it a narrower systemic side-effect profile than non-selective tocolytics such as beta agonists.
Is Atosiban FDA approved?
No. Atosiban is not approved by the FDA for any indication and is categorised as prescription-only. It has not been reviewed for safety or efficacy as a medicine, and published research should be read as investigation rather than established use.
What peptides are similar to Atosiban?
Compounds most often compared with Atosiban include Oxytocin, Carbetocin, ARA 290 (Cibinetide) and Serelaxin. They are grouped by shared mechanism or research area rather than by equivalence, and their regulatory status and evidence base differ.
References
- Efficacy of atosiban for repeated embryo implantation failure: A systematic review and meta-analysis — Front Endocrinol (Lausanne), 2023External reference
- Randomised, triple-blind, placebo-controlled trial of atosiban in women with previous embryo implantation failure and abnormal uterine contractions undergoing single blastocyst-stage embryo transfer: a study protocol — BMJ Open, 2026External reference
- Atosiban versus placebo for threatened preterm birth (APOSTEL 8): a multicentre, randomised controlled trial — Lancet, 2025External reference
- Interventions to optimize embryo transfer in women undergoing assisted conception: a comprehensive systematic review and meta-analyses — Hum Reprod Update, 2022External reference
- The safety of tocolytics used for the inhibition of preterm labour — Expert Opin Drug Saf, 2016External reference
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Compiled by Peptide Library Editorial · Reviewed Aug 30, 2026 · Updated Aug 30, 2026 · Version 1
This Atosiban profile is compiled from published literature (5 cited studies linked above), public regulatory records and chemical registries. It describes what research reports; it is not medical advice, and nothing here is a dosing recommendation for humans. Peptide Library does not sell peptides. Editorial policy · How profiles are compiled · Report an error
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