Natural vs Synthetic Oxytocin in Labour: What Is Syntocinon?
Updated: 5 days ago
Natural oxytocin is produced by your body and released in pulses during labour. Synthetic oxytocin - often called Syntocinon in the UK - is given through a controlled intravenous drip. Both stimulate contractions, but they enter the body differently and are not experienced in exactly the same way.
Oxytocin is sometimes described as the “love hormone”, but it also has an essential physical role during labour and birth. It helps the uterus contract, supports the birth of the placenta and is involved in releasing milk after birth.
You may be offered synthetic oxytocin to start labour, strengthen contractions or reduce bleeding after birth. You may also hear it called artificial oxytocin, although synthetic oxytocin is the more accurate term.
Understanding the difference is not about presenting natural oxytocin as “good” and Syntocinon as “bad”. Synthetic oxytocin can be an important, and sometimes lifesaving, intervention. This UK-focused guide explains why it may be offered, how it differs from the oxytocin your body produces, how it is monitored and which questions you can ask.
What does natural oxytocin do during labour?
Natural oxytocin - also known as endogenous oxytocin - is made in the hypothalamus in the brain. It is released into the bloodstream from the posterior pituitary gland and is also involved in signalling within the brain.
During labour, oxytocin binds to receptors in the muscular wall of the uterus and helps produce contractions. As the baby moves down and places pressure on the cervix and vagina, nerve signals travel to the brain and encourage further oxytocin release. This positive feedback process is known as the Ferguson reflex.
Natural oxytocin is released in pulses. Research suggests that the pulses increase in frequency and amplitude as labour progresses, particularly towards the birth of the baby.
Oxytocin is also involved in:
helping the uterus contract after birth
reducing blood loss after the placenta is born
triggering the milk-ejection or “let-down” reflex
wider brain processes associated with stress regulation, social interaction and caregiving
However, oxytocin does not act alone. Labour, feeding and bonding are influenced by many hormones, physical processes, individual circumstances and emotional and social factors.
What is Syntocinon and why is it used in labour?
Syntocinon is a brand name for synthetic oxytocin. During the first or second stage of labour, it is usually diluted and given into a vein through a carefully controlled drip.
It may be offered to:
induce labour, often after the cervix has begun to soften or open and the waters have been broken
augment labour, meaning strengthening or regulating contractions if labour has slowed
help the uterus contract during the third stage of labour
prevent or treat heavy bleeding after birth
This article focuses mainly on a Syntocinon drip used during the first and second stages of labour. The reason, dose and method may be different when synthetic oxytocin is used after birth.
Do Syntocinon contractions feel different?
They can do, although every person and every labour is different.
The body releases natural oxytocin in changing pulses as part of a responsive feedback system. A Syntocinon infusion enters the bloodstream continuously, and the dose is increased or reduced according to the contraction pattern and the baby’s response.
Contractions may therefore become stronger, longer or closer together. Some women describe this change as more intense, particularly if contractions increase quickly, while others cope well.
If you are offered Syntocinon, you can ask when pain-relief options will be available. Options may include breathing and relaxation techniques, movement, water where clinically appropriate, gas and air, opioid medicines or an epidural, depending on your circumstances and place of birth.
Does synthetic oxytocin work in the brain like natural oxytocin?
Not in exactly the same way.
Natural oxytocin is part of a wider system involving release into the bloodstream and signalling within the brain. Oxytocin given through a drip acts mainly through receptors around the body - including those in the uterus - and does not readily cross the blood–brain barrier.
This means intravenous synthetic oxytocin should not be assumed to reproduce all the central brain effects associated with the body’s own oxytocin system. However, it is equally inaccurate to claim that Syntocinon simply “switches off” natural oxytocin or prevents emotional connection.
What are the possible benefits and risks of Syntocinon?
The balance of benefits and risks depends on why Syntocinon is being recommended and on your individual circumstances.
Potential benefits may include:
starting contractions when induction is recommended
strengthening contractions when labour is not progressing as expected
helping labour progress sooner in some situations
supporting effective uterine contraction after birth
preventing or treating heavy bleeding after birth
Possible risks and practical considerations may include:
contractions becoming too frequent, long or strong
changes in the baby’s heart-rate pattern
the need for a cannula, infusion pump and continuous monitoring
movement or use of the birth environment being affected
needing additional pain relief
uncommon medicine-related side effects, which your maternity team should explain in relation to your health
The safest choice is not identical for every person. Ask your midwife or obstetrician to explain the expected benefit and risk for you and your baby, rather than only discussing Syntocinon in general terms.
Why is continuous monitoring recommended with a
Syntocinon drip?
If the uterus responds too strongly, contractions can become too frequent or last too long. This is called uterine hyperstimulation or tachysystole. When there is not enough time between contractions, placental blood flow may be temporarily reduced and the baby may have less time to recover.
For this reason, NICE recommends continuous monitoring of the baby’s heartbeat with cardiotocography (CTG) when oxytocin is used during labour. The contraction pattern is monitored too. The infusion can be reduced or stopped if contractions become too frequent or if there are concerns about the baby’s heart-rate pattern.
A drip and CTG can affect movement, but they do not necessarily mean you must remain lying on a bed. Depending on your clinical circumstances and the equipment available, you may still be able to stand, change position, sit on a birth ball or move around the bed. Ask your midwife what is possible in your birth setting.
Does Syntocinon affect bonding or breastfeeding?
There is not enough good-quality evidence to say that receiving Syntocinon will prevent bonding or make breastfeeding fail.
Some observational studies have found associations between synthetic oxytocin exposure and aspects of breastfeeding or newborn behaviour. However, these studies cannot easily separate the medicine from the reasons it was needed, the length and complexity of labour, epidural use, operative birth, maternal health and other clinical factors.
Bonding is not a single hormonal moment. Needing intervention does not make your birth less valid or your connection with your baby less powerful.
If feeding gets off to a difficult start after any kind of birth, skilled and compassionate support matters. When appropriate and wanted, skin-to-skin contact, responsive care, help with positioning and attachment, and early assessment of feeding concerns can all be valuable.
How can natural oxytocin be supported during labour?
No environment or comfort measure can guarantee that labour will begin or progress without medical support. Sometimes synthetic oxytocin is recommended despite excellent preparation and continuous care.
Many people nevertheless find that the following help them feel safer and more settled:
familiar and trusted support
privacy and fewer unnecessary interruptions
warmth and low lighting
calm communication and reassurance
touch or massage, if wanted
freedom to move and change position
feeling heard and involved in decisions
These measures remain valuable during an induction or medically complex birth. Physiological support and clinical care do not have to be opposing approaches.
If you are exploring your options, you may also find my guide to why families choose doula support helpful. A doula does not replace your midwife or medical team, but can offer continuous emotional, practical and informational support.
Can I decline Syntocinon during labour?
Syntocinon should be offered as part of an informed discussion not presented as something being done without explanation.
You can ask why it is being recommended, what the expected benefits and risks are, whether there are reasonable alternatives and what may happen if you wait or decline. Your maternity team can explain whether the situation is urgent and how different options relate to your individual clinical circumstances.
Consent is an ongoing conversation. Agreeing to an intervention does not remove your right to ask for an explanation, request a review or discuss changing your mind.
Questions to ask before agreeing to Syntocinon
The BRAIN framework can help you explore an offered intervention:
Benefits: What are the expected benefits for me and my baby?
Risks: What are the possible risks or side effects in my circumstances?
Alternatives: Are there other reasonable options, including waiting and reassessing?
Instinct: How do I feel after hearing the information?
Nothing or next: What might happen if we do nothing for now, and when will the situation be reviewed?
You may also wish to ask:
Why is Syntocinon being recommended now?
How has it been decided that my labour has slowed?
What dose will be used and how will it be increased?
What monitoring is recommended and why?
What will happen if contractions become too frequent?
What options will I have for movement and pain relief?
Can I have time to discuss this with my birth partner or doula?
Frequently asked questions about oxytocin in labour
Is Syntocinon the same as natural oxytocin?
Syntocinon contains synthetic oxytocin and activates the same type of receptor in the uterus. However, natural oxytocin is released by the body in pulses, while Syntocinon is usually delivered continuously through a controlled drip during labour.
Is synthetic oxytocin the same as artificial oxytocin?
Yes. People often use “artificial oxytocin” to mean the manufactured medicine. Synthetic oxytocin is the more accurate term, and Syntocinon is a brand commonly used in UK maternity care.
Why might I need an oxytocin drip?
An oxytocin drip may be offered to induce labour or strengthen contractions when labour has slowed. Synthetic oxytocin is also used in different doses or forms after birth to help the uterus contract and reduce bleeding.
Are Syntocinon contractions more painful?
Syntocinon can make contractions stronger, longer or closer together, so some women experience them as more intense. Experiences vary, and you can discuss comfort measures and pain-relief options before and during the infusion.
Can I move around while receiving Syntocinon?
Often, yes. You will usually have a cannula, drip and continuous CTG monitoring, which can make movement less straightforward. Depending on your circumstances and the equipment available, you may still be able to change position, stand or use a birth ball.
Will Syntocinon stop me bonding with my baby?
There is no good evidence that Syntocinon prevents bonding. Bonding develops in different ways and at different times, and is influenced by many physical, emotional and social factors.
A balanced approach to oxytocin and informed choice
Natural and synthetic oxytocin both stimulate uterine contractions, but they enter the body differently. Natural oxytocin is part of a responsive hormonal system and is released in pulses. Syntocinon is administered through a controlled drip and adjusted according to the clinical situation.
Synthetic oxytocin is neither automatically necessary nor something to fear. What matters is that it is offered for a clear reason, used safely, monitored appropriately and discussed with you through genuine informed decision-making.
As a doula, I do not provide medical advice or make decisions for you. I can help you explore reliable information, prepare questions, communicate your wishes and feel supported whatever path your labour takes.
I provide warm, evidence-based doula support across Wiltshire and South Gloucestershire, as well as remote support throughout the UK. To talk about your pregnancy and birth wishes, contact Bloom With Jacqueline for a free, no-obligation discovery call.
Your pregnancy, your baby, your choices.
About the author
I am Jacqueline Harler, the founder of Bloom With Jacqueline and a Nurturing Birth-trained antenatal, birth and postnatal doula based in Chippenham. I support families across Wiltshire and South Gloucestershire with calm, compassionate and non-judgemental care for hospital births, home births, inductions, caesareans and the early postnatal period.
Last reviewed: 21 September 2026.
References and further reading
National Institute for Health and Care Excellence (NICE) (2023), Intrapartum care, NG235: Recommendations.
National Institute for Health and Care Excellence (NICE) (2021), Inducing labour, NG207: Recommendations.
Walter, M.H. et al. (2021), ‘The role of oxytocin and the effect of stress during childbirth: neurobiological basics and implications for mother and child’, Frontiers in Endocrinology, 12:742236. Read the review.
Uvnäs-Moberg, K. et al. (2019), ‘Maternal plasma levels of oxytocin during physiological childbirth – a systematic review with implications for uterine contractions and central actions of oxytocin’, BMC Pregnancy and Childbirth, 19:285. Read the systematic review.
Society for Endocrinology, You and Your Hormones: Oxytocin. Read the patient information.
This article provides general information and is not a substitute for personalised advice from your midwife, obstetrician or another qualified healthcare professional.
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