Can I take lymecycline while pregnant or breastfeeding?
A plain-words look at what the NHS, the US drug label and LactMed say about lymecycline.
In short
Pregnancy: Lymecycline is not recommended in pregnancy.
Breastfeeding: You might be able to take lymecycline during breastfeeding if your baby is healthy, although other medicines might be better. Speak to your doctor or pharmacist first, particularly if you need it for more than 3 weeks.
Your doctor, midwife or pharmacist can help you decide.
What this means for you
Pregnancy
- It can affect how your baby's teeth and bones develop.
- Your doctor can talk to you about prescribing another antibiotic instead.
Breastfeeding
- You might be able to take lymecycline during breastfeeding if your baby is healthy, although other medicines might be better.
- Speak to your doctor or pharmacist first, particularly if you need it for more than 3 weeks.
- The amount of lymecycline that reaches breast milk is not known, but it's probably low, and it should not give your baby side effects if you take it for a short time.
- There is a concern that when lymecycline is given directly to children for a long time, it can affect how their teeth and bones develop.
- However, this is very unlikely to happen when babies get lymecycline through breast milk.
- Side effects in breastfed babies from medicines their mother takes are very rare, but it's important to keep an eye on your baby whenever you take a medicine while breastfeeding.
When to get help
- Contact a healthcare professional or call 111 (NHS 111 in the UK) as soon as you can if your baby is feeding less well than normal, has diarrhoea or is being sick, has a rash, has oral thrush (a fungal infection in the mouth), or seems unusually irritable.
- For symptoms not mentioned here, or if you're worried about your baby, you can also speak to any healthcare professional or call 111.
Talk to your doctor or pharmacist
This page is educational, not advice for your own situation. Talk to your doctor, midwife or pharmacist before you start, stop or change any medicine in pregnancy or while breastfeeding.
The details: what each source says
Lymecycline in pregnancy
The NHS says
Lymecycline is not recommended in pregnancy.
It can affect how your baby's teeth and bones develop.
Your doctor can talk to you about prescribing another antibiotic instead.
In our words, from the NHS page Lymecycline (nhs.uk). Contains public sector information licensed under the Open Government Licence v3.0 (OGL v3.0). The NHS does not endorse this site.
Lymecycline while breastfeeding
The NHS says
You might be able to take lymecycline during breastfeeding if your baby is healthy, although other medicines might be better. Speak to your doctor or pharmacist first, particularly if you need it for more than 3 weeks.
The amount of lymecycline that reaches breast milk is not known, but it's probably low, and it should not give your baby side effects if you take it for a short time.
There is a concern that when lymecycline is given directly to children for a long time, it can affect how their teeth and bones develop. However, this is very unlikely to happen when babies get lymecycline through breast milk.
Side effects in breastfed babies from medicines their mother takes are very rare, but it's important to keep an eye on your baby whenever you take a medicine while breastfeeding.
Contact a healthcare professional or call 111 (NHS 111 in the UK) as soon as you can if your baby is feeding less well than normal, has diarrhoea or is being sick, has a rash, has oral thrush (a fungal infection in the mouth), or seems unusually irritable.
For symptoms not mentioned here, or if you're worried about your baby, you can also speak to any healthcare professional or call 111.
In our words, from the NHS page Lymecycline (nhs.uk). Contains public sector information licensed under the Open Government Licence v3.0 (OGL v3.0). The NHS does not endorse this site.
Other names
UK brand names (per the NHS): Tetralysal 300.
Sources
- NHS, Lymecycline (nhs.uk), page last reviewed 13 April 2026. Paraphrased. Contains public sector information licensed under the Open Government Licence v3.0.
Sources checked 26 September 2026. How we source and check every page.
Educational summary of named sources, not medical advice.