What is Oxytocin?
Oxytocin is an endogenous hormone, often called the "bonding" or "cuddle hormone." It plays a role in social bonding, trust, birth and breastfeeding. In the scene it is used for mood, a sense of closeness and general wellbeing, usually nasally.
Comparison
Hormone peptides in the lexicon
How oxytocin differs from other hormone peptides in the lexicon. Tap a card to open its entry.
Only for oxytocin is the receptor shown here. The classification of the others is in their entries. 9
How it works
Oxytocin acts at oxytocin receptors in the brain and influences social and emotional processes: more sense of connection, trust and relaxation in social situations. Because of the very short half-life, each dose acts only briefly and pointedly.
Where it acts
Where oxytocin acts
Tap a point or a card. The uterus, site of the approved use, is not part of the diagram.
- Brain
Oxytocin receptors for social behaviour, effect of the nasal spray in humans disputed3
OXTR - Kidney
Retains water, risk of water intoxication with long infusions (prescribing information)8
Observed in trials - Blood
After nasal spray levels far above natural values, little reaches the cerebrospinal fluid4
Observed in trials
Targets in the ChEMBL database9
Compound ChEMBL395429: one recorded mechanism, Agonist (according to ChEMBL).
- Gene
- OXTR
- UniProt
- P30559
- ChEMBL
- CHEMBL2049
- Action
- Agonist (according to ChEMBL)
Use (nasal or subcutaneous)
Dosing
Dosing
Dosing, titration and syringe
Loading the dosing information …
- Getting started and stepping up, drawn as a staircase
- Units on the U-100 syringe for every step
- How long one vial lasts
What the research shows
Oxytocin as a hormone is well researched, especially its role in birth, breastfeeding and social behavior. For targeted self-use to optimize mood or social function, the data is mixed and less clear-cut than often portrayed. Stay honest: an effect exists but is individual and not guaranteed.
Study results
What the trials measured
Interactive: switch tabs, tap points, show or hide arms. Arms are named relative to each other, no dosing advice.
Social withdrawal after 24 weeks1
Change on a scale from 0 to 39 points, lower is better
Both groups improved almost equally. The difference of 0.2 points was not significant. The secondary goals mostly did not differ either. Phase 2 trial aiming at a benefit for social behaviour.
Effect of oxytocin nasal spray versus placebo7
Effect size (Hedges g) from 17 trials with 466 people with developmental disorders
An effect size around 0.2 counts as small, around 0.5 as moderate. The authors consider the benefit tentative and call for better trials.
Research status
Where the research stands
On ClinicalTrials.gov 935 trials name oxytocin, most of them about birth. 263 test oxytocin as a nasal spray, mainly in phase 1 and 2. Shown is a selection of the larger nasal spray trials. As of 26 Oct 2026. 11
- Preclinical Principle: activation of the oxytocin receptor
- Phase 1 no registered trial
- Phase 2 4 trials, 3 completed
- Phase 3 4 trials, 2 completed, 1 stopped early
- Approval in obstetrics, not as a nasal spray for mood
Show all 8 phase 2 and 3 trials on a timelineHide timeline
SOARS-B · NCT01944046 · 290 participants, started Aug 2014, primary endpoint reached Nov 2017.
Registry entry ↗ · Results: Sikich et al., New England Journal of Medicine, 2021
NCT03046836 · 200 participants, started Jul 2017, primary endpoint reached Apr 2021.
Registry entry ↗ · Results not yet in PubMed
NCT04228289 · 180 participants, started Jan 2021, primary endpoint reached Feb 2025.
Registry entry ↗ · Results not yet in PubMed
NCT06194851 · 240 participants (planned), started Oct 2024, primary endpoint planned Sept 2028.
NCT02804373 · 50 participants, started Jun 2014, primary endpoint reached Jan 2019.
Registry entry ↗ · Results not yet in PubMed
NCT04210310 · 33 participants, started Jan 2020, stopped early May 2022.
NCT04283578 · 52 participants, started Mar 2020, primary endpoint reached Oct 2021.
Registry entry ↗ · Results not yet in PubMed
NCT04903002 · 336 participants (planned), started Apr 2022, primary endpoint planned Mar 2026.
Bar: start to primary endpoint (planned for running trials). Green = completed, blue = progress until 26 Oct 2026, grey = stopped early.
Side effects
- Generally well tolerated, occasionally headache or irritation of the nasal mucosa.
- Rarely nausea.
- Water retention: oxytocin holds water in the body. The US prescribing information of the injection warns of water intoxication with seizures up to coma when large amounts are given over a long time.
Tolerability
Side effects in the autism trial
Children and adolescents with autism, oxytocin nasal spray versus placebo over 24 weeks (SOARS-B).
| Event | Placebo | Oxytocin as a nasal spray |
|---|---|---|
| Any side effect1 | 83% | 82% |
| Increased appetite1 | 10% | 16% |
| Increased energy1 | 3% | 10% |
| Restlessness1 | 2% | 8% |
| Stopped because of a side effect1 | 2% | 3% |
| Serious event1 | 1% | 1% |
Values from the full text. Stops under oxytocin were mostly due to irritability or aggression. A review of 38 trials in adults found no side effects above placebo level with short-term use.16
Storage
Before mixing the powder is robust, normal room temperature (around 20 to 25 degrees) is fine, ideally kept in the dark. After mixing, keep in the fridge (2 to 8 degrees), do not freeze. It stays good there for at least 4 to 6 months with barely any loss of potency, in practice considerably longer. Swirl or shake to mix, both are fine.
Shelf life
How long it keeps
Robust, no fridge needed.
At least 4 to 6 months with barely any loss of potency.
- Keep it dark
- Dissolved: 2 to 8 degrees
- Note the mixing date on the vial
