If you are pregnant, breastfeeding, trying to conceive, or could become pregnant, cannabis-based medicines need advice from a specialist who understands both pregnancy and medical cannabis. This guide should not be read as reassurance that medical cannabis is safe in pregnancy or breastfeeding. Product-specific warnings matter, and decisions can affect both the patient and a baby.
The useful action is disclosure, not guesswork. Tell your prescriber if you are pregnant, planning pregnancy, breastfeeding, trying to conceive, or using any non-prescribed cannabis or CBD product. Do not start, stop or change prescribed medicines without clinical advice, especially if the medicine is being used for a condition where sudden changes could cause harm.
For the wider UK route, start with the MCPH patient guide. For general prescribing boundaries, read how the UK medical cannabis prescription process works. For safety context, read medical cannabis side effects.
The short answer
NICE NG144 says cannabis-based medicinal products should not be offered during pregnancy or breastfeeding unless the potential benefit outweighs potential risks. It also says people who could become pregnant should be advised about potential risks and contraception where relevant.
That is a high bar. It means any decision needs an individual specialist-led risk discussion, with the underlying condition, alternative treatments, product information, pregnancy or breastfeeding context and monitoring considered carefully.
Food CBD guidance is a separate area, but it points in the same cautious direction for non-medicinal CBD products. Patients should not use over-the-counter CBD or non-prescribed cannabis as a safer workaround during pregnancy, breastfeeding or fertility treatment.
Pregnancy: do not assume safety
Pregnancy changes the risk calculation for any medicine. For cannabis-based medicines, the problem is not only known harm. It is also uncertainty, limited human safety data, and differences between products.
Official product information can include pregnancy and contraception warnings. Sativex product information says it should not be used during pregnancy unless the potential benefit outweighs the risk to the foetus or embryo, and it includes contraception advice. Epidyolex product information also has pregnancy and contraception cautions that need specialist interpretation.
For patients, the practical message is simple: tell the prescribing clinic or specialist as early as possible if pregnancy is possible or confirmed. Also tell the midwife, obstetric team, GP surgery or relevant NHS team that a cannabis-based medicine has been prescribed, so care is not split across disconnected records.
Breastfeeding: avoid reassurance
Breastfeeding also needs clinician review. NICE’s cannabis-based medicinal products guidance does not support casual use during breastfeeding. Product-specific information may advise against use during breastfeeding or require a careful risk-benefit decision.
The article cannot say a prescribed cannabis medicine is safe for a breastfed baby. It also cannot tell someone to stop breastfeeding or stop a prescribed medicine. That decision belongs with the patient and clinical team, using the exact medicine, dose, underlying condition and baby context.
If you are already prescribed and breastfeeding, or planning to breastfeed, contact the prescriber before making changes. Ask what the product information says, what alternatives exist, and who is responsible for follow-up.
Fertility and trying to conceive
Fertility is another area where MCPH should avoid overclaiming. There is public discussion about cannabis and fertility, but that does not automatically translate into clear, product-specific advice for prescribed cannabis medicines.
Some official product information includes contraception advice or reproductive-risk warnings. The Food Standards Agency also advises that some groups, including people who are pregnant, breastfeeding or trying to conceive, should not consume CBD food products. That FSA guidance is about consumer CBD products, not prescription medicines, but it reinforces that this is not a low-risk self-experiment area.
If you are trying to conceive, going through fertility treatment, or worried about sperm, ovulation, miscarriage risk or pregnancy planning, raise it with the prescriber and fertility or maternity team. The answer may depend on the medicine, the reason it was prescribed, alternative treatment options and the risk of leaving the underlying condition undertreated.
What to tell the prescriber
Be direct. The prescriber needs the real context, not a cleaned-up version of it. That may include:
- current pregnancy, possible pregnancy, or plans to conceive
- breastfeeding or plans to breastfeed
- fertility treatment or fertility concerns
- all prescribed medicines, over-the-counter medicines and supplements
- non-prescribed cannabis, CBD oils, vapes, edibles or other products
- previous side effects, mental-health history and substance-use concerns
- who else is involved in care, such as a midwife, obstetrician, neurologist, pain team or fertility clinic
This is not about judgement. It is about avoiding hidden risks and making sure the right clinical team is involved.
Questions to ask
Useful questions include:
- What does the product information say about pregnancy, contraception, breastfeeding and fertility?
- Is there a safer, better-studied alternative for this condition during pregnancy or breastfeeding?
- What is the risk of changing or stopping the medicine compared with continuing it?
- Who is coordinating the decision: the cannabis prescriber, NHS specialist, GP surgery, midwife, obstetric team or fertility clinic?
- What monitoring is needed for me and, if relevant, the baby?
- What should I do if I become pregnant unexpectedly while using this medicine?
Do not treat internet anecdotes, clinic marketing or product labels as enough for this decision.
What this means in plain English
Pregnancy, breastfeeding and fertility are not ordinary access questions. They change the safety discussion.
MCPH can help patients know what to disclose and what to ask, but the advice needs to come from the specialist looking after the pregnancy, breastfeeding or fertility question and the clinician responsible for the cannabis medicine. Ask for that review before starting, continuing, stopping or changing anything.
Sources
- NHS. Medical cannabis. https://www.nhs.uk/medicines/medical-cannabis/
- NICE. Cannabis-based medicinal products, NG144. https://www.nice.org.uk/guidance/ng144
- NHS England. Cannabis-based products for medicinal use. https://www.england.nhs.uk/long-read/cannabis-based-products-for-medicinal-use-cbpms/
- GMC. Information for doctors on cannabis-based products for medicinal use. https://www.gmc-uk.org/professional-standards/learning-materials/information-for-doctors-on-cannabis-based-products-for-medicinal-use
- CQC. Cannabis-based medicinal products: what CQC expects providers to consider. https://www.cqc.org.uk/guidance-providers/healthcare/cannabis-based-medicinal-products-what-cqc-expects-providers
- GOV.UK. Supply unlicensed medicinal products, specials. https://www.gov.uk/government/publications/supply-unlicensed-medicinal-products-specials
- Food Standards Agency. Cannabidiol CBD guidance. https://www.food.gov.uk/business-guidance/cannabidiol-cbd
- Electronic Medicines Compendium. Sativex Oromucosal Spray SmPC. https://www.medicines.org.uk/emc/product/602/smpc
- Electronic Medicines Compendium. Epidyolex 100 mg/ml oral solution SmPC. https://www.medicines.org.uk/emc/product/10781/smpc
