What is oxytocin?

Oxytocin is a natural hormone made in the brain. It is stored and released into the blood stream by the pituitary gland.

Oxytocin plays a key role in both the female and male reproductive systems. This includes increasing contractions to induce labour and birth, and the release of milk from the breast after birth.

It also acts as a chemical messenger in your brain and influences important elements of human behaviour such as social recognition, relationship formation and long-term emotional attachment.

What is the role of oxytocin?

Oxytocin has an important role in many human behaviours and social interactions, including:

• sexual arousal
• allowing people to recognise each other
• promoting trust
• building relationships and romantic attachment
• promoting parent-infant bonding

Oxytocin plays an important role in birth and breastfeeding. Here, it's two main roles are to stimulate contractions of the uterus in labour and to stimulate the flow of breastmilk after childbirth.

Oxytocin builds during labour making the uterus contract more frequently, more effectively and with more intensity. Oxytocin is essential for labour to progress.

Sometimes oxytocin is given as a medicine to help start or strengthen your contractions. It is also used to help your placenta to be delivered, or to help your womb contract after childbirth to prevent or stop heavy bleeding. Having oxytocin is not suitable in all situations — your doctor will give you more information if oxytocin is right for you.

Oxytocin is also naturally present in males. Its function is to regulate sperm production and movement, testosterone production by the testicles, help reach orgasm and increases the sleepiness felt after orgasm.

What happens if I have too much oxytocin?

When oxytocin is released, it stimulates your pituitary gland to release even more of it.

It is thought that too much oxytocin could lead to benign prostatic hypertrophy (BPH) in males. This is a common condition in the prostate gland which makes it difficult to urinate.

Too much oxytocin in labour, can cause the uterus to contract too much. This is particularly true if you have certain risk factors, such as diabetes or abnormal glucose levels during pregnancy or heart problems. Because of this, your health team will monitor you carefully if they give you oxytocin in labour.

What happens if I have too little oxytocin?

Low levels of oxytocin could slow or stop uterine contractions during the birthing process and prevent milk flow after your baby is born.

Because oxytocin is involved in creating emotional bonds and sexual arousal, there are other effects of having too little oxytocin. Signs and symptoms include:

• irritability and inability to feel affectionate
• increased feelings of anxiety
• difficulty achieving orgasm
• disturbed sleep

How can I adjust my oxytocin levels?

Oxytocin can be used to as a medicine in some situations. Oxytocin can be given during labour via a drip to start contractions or to strengthen them. It can also be a medicine used for termination of pregnancy.

Research has shown that oxytocin levels can be increased naturally with pleasurable activities, for example:

• exercising
• listening to music
• patting a dog
• massage
• physical touch, such as cuddling, sex or giving a hug

When should I see my doctor?

If your pregnant or breastfeeding, do not use oxytocin except under a doctor's care.

Tell your doctor if you have ever had:

• a severe infection in your uterus
• a difficult labour because you have a small pelvis
• genital herpes
• cervical cancer
• surgery on your cervix or uterus (including a prior Caesarean section)
• high blood pressure
• heart problems

Tell your doctor or nurse as soon as possible if you do not feel well after having oxytocin.

Resources and support

Call healthdirect on 1800 022 222 (known as NURSE-ON-CALL in Victoria) for more information and advice. A registered nurse is available 24 hours a day, 7 days a week.

Pregnancy, Birth and Baby's video call service allows you to speak face-to-face with a maternal child health nurse. Video call is a free service and is available from 7am to midnight (AET), 7 days a week (including public holidays).