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FACTSHEET

Codeine and Breastfeeding

If you have any questions about this information, you can contact the Drugs in Breastmilk team through their Facebook page or on druginformation@breastfeedingnetwork.org.uk.

The NHS and MHRA recommend you do not use codeine if you are breastfeeding.  

Paracetamol and ibuprofen are the recommended first choices for pain relief.  
 
If you need opioid pain relief, dihydrocodeine, at the lowest effective dose for the shortest duration possible, is the preferred opioid option.

If you have taken some codeine or co-codamol, the risk of adverse effects is low, and you can continue breastfeeding as normal.  Switch to a pain relief drug that is compatible with breastfeeding and observe your baby for side effects including breathing problems, drowsiness or poor feeding.
 
This information applies only if your baby was born at full-term and has no breathing difficulties or other health concerns.   

Seek immediate medical attention if your baby develops side effects.  

During lactation analgesics such as paracetamol or ibuprofen (unless contraindicated) should preferably be used and opioids only considered as a third line analgesics. For more information, see our factsheet on pain relief.

Sometimes, while you are breastfeeding, you might take/be prescribed one or two doses of codeine/co-codamol accidentally or when nothing else is available. In these circumstances the risk of adverse effects is low and breastfeeding can continue as normal. Your baby should be observed for drowsiness and other side effects (see list below). This applies only if your baby was born at full term and has no breathing difficulties. See the Breastfeeding and Medication page on an accidental dose of codeine for more information.

In June 2013, the MHRA issued guidance that codeine should no longer be used when breastfeeding. This is due to the concern that individuals vary in the way their bodies metabolise codeine. 

Codeine is converted to morphine in the liver by the CYP2D6 enzyme. There are many genetic variations of CYP2D6, which affect the extent of this conversion in individuals. This leads to differences in the plasma levels of morphine and different levels of pain relief. This then leads to a variable and unpredictable risk of side effects due to morphine’s action on the brain and respiratory centre. For some this can result in no benefit from the drug, for others that they experience excessive drowsiness and constipation. For breastfeeding mothers in the latter group this may also lead their babies to experience respiratory depression. 

Codeine combinations have in the past formed the mainstay of analgesic use, particularly in the early postpartum period. The genotype producing ultra rapid metabolism is rare but is impossible to identify without genetic testing.

If you have never taken codeine preparations before, you may be unaware of whether you might be an ultra-rapid metaboliser, putting you and your baby at risk of adverse effects. Approximately 3% of Europeans have this genotype (vanderVaart 2011). In most people only 10% of codeine is converted into morphine but this can vary according to the genetic variation (and rapid metabolisers can convert 50% more codeine into morphine, whilst those with no active CYP2D6 genes convert almost no codeine into morphine and find it ineffective). Postpartum pain, due to either caesarean section (c-section) or episiotomy, is a major reason for the prescription of codeine, with an estimated 30% of North American women using the drug (vanderVaart 2011). 

The UKMI Specialist Pharmacy Service states that dihydrocodeine and tramadol may be considered if you require opioids while breastfeeding but that the possibility of you being an ultrarapid metaboliser cannot be ignored even with these drugs. If opioids are prescribed and adverse effects develop in breastfeeding infants, the possibility of opioid toxicity should be considered regardless of the maternal dose. In such cases, the opioid should preferably be replaced by an alternative non-opioid analgesic and breastfeeding interrupted until the cause of the symptoms is clear. 

Use of any opioid while breastfeeding, if necessary (and only as third line choice of medication after the use of regular paracetamol and non-steroidal anti-inflammatories – see our factsheet on pain relief for more information), should be at the lowest effective dose, for the shortest possible duration, regardless of your baby’s age. You should stop taking the drug and seek medical advice if you notice side effects in your baby such as: 

  • Breathing Problems
  • Lethargy
  • Poor feeding or not waking to feed
  • Drowsiness
  • Bradycardia – slow heart rate

If adverse effects develop in breastfeeding infants the possibility of opioid toxicity should be considered, regardless of maternal dose. The opioid should be replaced by a suitable non-opioid analgesic (LactMed, Hale). 

Breastfeeding should not be interrupted unless the symptoms are extreme e.g. necessitating admission, and then only for the shortest duration possible, in line with NICE recommendations (NICE 2025). 

You should be fully informed of the risks before being sold or prescribed codeine or any opioid and watch your nursling carefully for any signs of increased drowsiness – sleeping longer or more frequently or not feeding as much or not gaining weight as expected. This can be evident whatever the age of the nursling and it should not be assumed that an older baby is not at risk. 

Using the half life of codeine as 3 hours – it takes 15 hours for a dose to be regarded as no longer in breastmilk. 

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References

©The Breastfeeding Network. Published November 2021, last amended June 2026