Oxytocin is a nine-amino-acid hormone made in the hypothalamus. Its approved use is unglamorous and well established: intravenous oxytocin induces and augments labour and controls postpartum bleeding, given in hospital with continuous monitoring because too much causes dangerously strong contractions.
What people buy is the nasal spray, on the strength of a body of research from the late 2000s reporting that intranasal oxytocin increased trust, generosity and the reading of emotional expressions. Those studies drove a great deal of enthusiasm and a great deal of product.
That literature has not held up well. Large replication attempts have repeatedly failed to reproduce the social effects, and trials in autism, the most serious clinical application, have been largely negative, including a substantial multi-site study. There is also an unresolved question underneath all of it: how much intranasally administered oxytocin actually reaches the brain, and whether the doses used produce meaningful central concentrations at all.
How it works
Oxytocin binds oxytocin receptors, causing uterine smooth muscle to contract and milk to be released during breastfeeding. That peripheral physiology is well characterised and is what the approved use relies on.
In the brain, oxytocin is involved in social bonding, and animal work, particularly in voles, has shown clear effects on pair bonding. Whether that translates to humans at the doses used is the question the replication failures are about.
The delivery problem sits under everything: peptides do not cross the blood–brain barrier readily. Intranasal administration is meant to bypass it via the olfactory route, and how much actually arrives centrally is genuinely disputed.
It also has weak antidiuretic activity. Which is why very high or repeated doses can cause water retention and dangerously low sodium.
Regulatory status — United States
Approved by the FDA and EMA as an intravenous or intramuscular injection for obstetric use. Intranasal preparations sold for social or wellbeing purposes are compounded or research-chemical products with no approval for that use in the United States.
Last reviewed 18 Aug 2026. Regulatory positions in this category change frequently; we date this line so you can see how current it is.
What it is studied for
Each entry states the evidence behind it. We do not rank indications by effectiveness — for most compounds here, that would be a claim nobody can support.
Labour induction and postpartum haemorrhage
Published reviewThe approved use.
EvidenceDecades of obstetric practice and trial evidence. Given intravenously with continuous fetal and uterine monitoring.
Social behaviour, trust and bonding
Clinical trialWhat the nasal spray is sold for.
EvidenceEarly studies reported effects on trust and emotion recognition. Large replication attempts have largely failed, and the effect sizes in the original literature show the pattern typical of publication bias.
Autism spectrum disorder
Clinical trialThe most seriously pursued clinical application.
EvidenceA large multi-site randomised trial in children found no benefit on social withdrawal compared with placebo.
Identity and clearance
Molecule
- Class
- Cyclic nonapeptide hormone
- Molecular weight
- 1007.2 Da
- Length
- 9 amino acids
Dose protocols reported in sources
Displayed for reference only. Every row says where it came from, and a trial protocol and a community convention are not the same kind of information. None of this is fed into the calculator, and none of it is a recommendation.
| Goal | Dose | Frequency | Route | Units, 2 mg vial | Source | Start this protocol |
|---|---|---|---|---|---|---|
| Doses used in the intranasal research literature | 40 mcg – 80 mcg | A single administration in most study protocols | Nasal24 to 48 IU is the range these studies used, expressed here in micrograms. Note that this is the dose whose effects have largely failed to replicate. It describes what was studied, not what we suggest. | 10–20 u | Clinical trial | Start this |
| Obstetric use | 1 mcg – 20 mcg | Continuous intravenous infusion, titrated to contractions | IntravenousTitrated in milliunits per minute against continuous fetal and uterine monitoring, because excessive stimulation causes uterine rupture and fetal distress. Nothing about this transfers outside a delivery suite. | 0.25–5 u | Published review | Start this |
Start this copies a row into a protocol of your own, which you can then edit. Where a source gave a dose range or an ambiguous frequency, those fields arrive empty — we will not pick a number on your behalf.
Calculator
Work out what to draw
Pre-filled with a 2 mg vial as a worked example. These are not recommended values — change them to match the vial in front of you.
Draw to 5 units on a 1 mL U-100 syringe. That is 0.05 mL, containing 50 mcg of Oxytocin.
Check5 units falls between the printed lines on a 1 mL U-100 syringe. Mixing with 1.6 mL of water instead would put this dose at 4 units.
Bioalmanac performs arithmetic on values you enter. It does not recommend doses, schedules or compounds, and nothing here is medical advice. Confirm every calculation against your vial and syringe before drawing, and speak with a licensed healthcare provider.
Open this calculation in the full calculator
Units, concentration, bacteriostatic water — the glossary defines the vocabulary, and a unit is not a fixed volume.
Safety
Reported effects
- Generally well tolerated intranasally in study conditionsClinical trial
In short research protocols
Those protocols were single doses in supervised settings. Repeated daily use has not been characterised the same way.
- Nasal irritation, headacheClinical trial
Common with nasal use
- Hyponatraemia and water retentionPublished review
With high or repeated doses
Oxytocin has weak antidiuretic activity. Severe low sodium causes confusion, seizures and can be fatal. This is the mechanism worth respecting with daily use.
- Uterine hyperstimulationPublished review
With obstetric use
Why hospital administration is continuously monitored. Excessive contraction causes fetal distress and uterine rupture.
- Blunted rather than enhanced social responsesClinical trial
Reported in parts of the literature
Some studies found increased in-group favouritism and out-group wariness rather than a general increase in trust. 'The love hormone' is a headline, not a summary.
When to stop
- Headache with confusion, nausea or drowsiness. Possible low sodium. Seek urgent assessment.
- Noticeable swelling or rapid weight gain.
- Abdominal cramping, in anyone who could be pregnant. Seek urgent care.
- Persistent nasal irritation or bleeding.
Interactions and situations that need care
- Pregnancy, outside a delivery suiteAvoid
Oxytocin causes uterine contraction. That is its approved purpose, given intravenously with continuous fetal monitoring because the margin between augmenting labour and causing harm is narrow. Self-administering it while pregnant is the most dangerous use of anything on this page.
- Daily or repeated dosingUse caution
The antidiuretic activity means water retention and low sodium accumulate with repeated dosing. The research protocols were single doses in supervised settings, so the safety impression they give does not extend to daily use.
- Treating autismUse caution
This was pursued seriously and a large multi-site randomised trial found no benefit. Families are marketed to on the strength of the early enthusiasm, not the result that followed it.
- BreastfeedingUse caution
Oxytocin triggers milk let-down. Effects on established feeding are not characterised for non-medical use.
What to expect
- The obstetric use is real, approved medicine given in hospital with continuous monitoring.
- The social effects that made it famous have largely failed to replicate at scale.
- The autism trials, which were the serious clinical application, were negative.
- How much intranasal oxytocin reaches the brain is genuinely disputed, which sits underneath every finding either way.
- It has antidiuretic activity. Repeated dosing risks low sodium, which is the one way this becomes dangerous outside pregnancy.
- 'The love hormone' is a headline. Parts of the literature found increased in-group favouritism rather than general warmth.
Storage and handling
- Freeze-dried powder
- Refrigerated at 2–8 °C.
- After mixing
- Refrigerated at 2–8 °C. Nasal solutions are handled more than injectables and contaminate more easily.
- Long-term, frozen
- Unopened powder is stable at −20 °C or colder.
Checking your vial
Research chemicals carry no manufacturing standard, so what the vial looks like is often the only quality signal available before you use it. More on assessing quality and COAs.
Clear, colourless solution
Normal.
Cloudiness or particles
Discard it.
Questions
- Does the nasal spray actually do anything?
- The early trust and bonding studies drove enormous interest and have largely failed to replicate. Trials in autism were negative. Underneath all of it is an unresolved question about how much gets to the brain by that route at all.
- Is it dangerous?
- In single research doses it was well tolerated. Two real risks. Low sodium from repeated dosing, and, far more seriously, uterine contractions, which make self-administration during pregnancy genuinely dangerous.
References
Oxytocin injection: FDA prescribing information
US Food and Drug Administration, 2023 · Regulatory label
Obstetric use · Intravenous infusion titrated in milliunits per minute
Approved for induction and augmentation of labour and control of postpartum bleeding, with continuous fetal and uterine monitoring required. Warnings include uterine hyperstimulation and water intoxication with hyponatraemia from the antidiuretic effect.
Intranasal oxytocin and social behaviour: replication failures and evidential value
Psychological and neuroscience literature, 2017 · Replication studies and meta-analytic reviews
Healthy adult volunteers across many studies · 24 to 48 IU intranasally
Large replication attempts have repeatedly failed to reproduce reported effects on trust and emotion recognition. Analyses of the published literature show effect-size patterns consistent with publication bias, and central bioavailability by the intranasal route remains disputed.
Intranasal oxytocin in children and adolescents with autism spectrum disorder
New England Journal of Medicine, 2021 · Randomised, placebo-controlled, multi-site trial
290 children and adolescents with autism spectrum disorder · Intranasal oxytocin, titrated, over 24 weeks
No significant benefit over placebo on the primary measure of social withdrawal, and no significant differences on secondary measures.
10.1056/NEJMoa2103583
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Next
What to do with Oxytocin
- Keep a record of itTurn a dose and a schedule into a protocol, then log what you actually take. Oxytocin is filled in for you.
- See what it costsPer-milligram prices read from vendor sites and confirmed by a person, so vial sizes compare.
- Check a combinationWhat our profiles record about Oxytocin alongside each other compound — including the pairs where nothing is recorded.
Keep this page honest
If something here is wrong, out of date, or missing a source, tell us and we will fix it and say that we did.
This page is educational. It describes what published research reports, not what you should do. Peptides discussed here are largely not approved for human use, and nothing on Bioalmanac is medical advice. No clinician reviews these pages.
Page last updated 18 Aug 2026