This NHS content is written for people in England. Medicine names, availability, prescribing and services may differ in other countries.
Diphenhydramine and pregnancy
Diphenhydramine can be used during pregnancy, but it's not normally recommended. This is because of the side effects of feeling drowsy during the day and feeling dizzy, which may be worse during pregnancy.
Talk to your doctor or pharmacist about other antihistamines, such as chlorphenamine, that may be more suitable.
If you have difficulty sleeping while you're pregnant, your doctor or midwife will be able to suggest ways to improve your sleep.
If you have a cough or cold, you can help to ease your symptoms by resting, drinking plenty of fluids and taking paracetamol.
Diphenhydramine and breastfeeding
If your baby is healthy, you can take diphenhydramine tablets or liquid while you're breastfeeding.
Diphenhydramine passes into breast milk in very small amounts. Your baby is unlikely to get side effects. However it's better to only take it occasionally, or for a short time, as it could make them sleepy. Other non-drowsy medicines might be better, especially if you need to take it for a longer time.
Medicines containing diphenhydramine that you buy from a pharmacy may also contain other ingredients. Check with a pharmacist or doctor first if you're breastfeeding.
It's OK to use diphenhydramine cream if you're breastfeeding. It's not thought to pass into breast milk, or cause any side effects in breastfed babies. Take care that your baby does not touch any areas of your body where you've used it. Wash your hands after you have used it and before picking up your baby.
It's very rare for breastfed babies to have side effects from medicines you're taking. But it's important to keep monitoring your baby if you're taking any medicine while breastfeeding.
Contact your healthcare professional or call 111 as soon as possible if your baby:
- is not feeding as normal, or not waking to feed
- seems unusually sleepy
- is being irritable
If your baby has any symptoms that are not listed, or if you're worried about them, you can also call 111 or contact any healthcare professional.
Keep breastfeeding as usual until you've got advice about your baby's symptoms.
It's important not to share a bed with your baby while you're taking diphenhydramine tablets or liquid.
View the original NHS website page ↗. Refreshed 19 August 2026.
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