HRT and Breastfeeding
What You Need to Know
Breastfeeding naturally changes a woman’s hormones.
Prolactin rises to support milk production, while oestrogen levels remain low. This can sometimes cause symptoms that feel very similar to menopause, including:
Hot flushes and night sweats
Vaginal dryness
Pain during sex
Urinary discomfort or recurrent urinary infections
Poor sleep
Brain fog
Low mood or anxiety
Reduced libido
Joint aches and fatigue
Some women may also already have premature ovarian insufficiency, early menopause, surgical menopause or another medical reason for needing HRT.
The question is therefore not simply, “Can I take HRT while breastfeeding?”
The better question is:
Which hormones are needed, what is the safest route, and how can we protect both the mother’s wellbeing and her milk supply?
Can You Use HRT While Breastfeeding?
In some circumstances, yes.
Breastfeeding and HRT are not automatically incompatible. However, there is limited research because breastfeeding women are rarely included in medication studies.
The main concern is usually not that HRT will harm the baby. The main concern is that systemic oestrogen may reduce breast milk production, particularly if it is started soon after birth.
The decision should take into account:
The age and health of the baby
Whether the baby was born prematurely
Whether breastfeeding is fully established
Whether breast milk is the baby’s only source of nutrition
The severity of the mother’s symptoms
Why HRT is needed
Which hormones and doses are being considered
Whether the mother has additional blood-clot risk factors
Why Can Oestrogen Reduce Milk Supply?
Milk production is supported by prolactin.
Oestrogen can interfere with the hormonal signals that establish and maintain milk production. This is why oestrogen-containing contraception is usually avoided during the early weeks of breastfeeding.
Not every woman will experience a reduction in supply. However, the risk appears to be greater:
During the first six weeks after birth
Before breastfeeding is firmly established
When higher doses of oestrogen are used
When the baby depends entirely on breast milk
When milk production was already low or difficult to establish
A reduction in supply may happen within a few days of starting oestrogen.
If this occurs, milk production may improve after reducing the dose or stopping the oestrogen. This should be discussed with the prescriber rather than stopping treatment without advice.
Oestrogen Patches and Gel
If systemic oestrogen is needed, oestradiol through the skin is generally the preferred route.
This includes:
Oestrogen patches
Oestrogen gel
Studies of oestradiol patches have found no measurable increase in breast-milk oestradiol, and very little is expected to reach the baby. However, evidence for oestrogen gel is more limited. Oestrogen may still reduce milk production, even when very little reaches the baby.
However, oestrogen may still reduce milk production, even when only a small amount reaches the baby.
The usual approach is to:
Use the lowest dose that adequately controls symptoms
Wait until breastfeeding is established, usually around six weeks after birth, where clinically reasonable
Monitor milk production after starting treatment
Monitor the baby’s feeding and weight gain
Review the dose if milk supply clearly falls
Do not apply oestrogen gel or spray to the breasts.
Apply it to the recommended area, wash your hands afterwards and allow the skin to dry before holding the baby. The baby should not touch or lick the application site.
What About Oral Oestrogen?
Oral oestrogen is usually not the preferred option during the early postnatal period.
This is because oral oestrogen:
Passes through the liver
Has a greater effect on clotting proteins
May carry a higher blood-clot risk than transdermal oestradiol
May be more likely to affect milk production
The risk of blood clots is already increased after childbirth, especially during the first six weeks.
When HRT is necessary, transdermal oestradiol is therefore usually the more sensible systemic option.
Micronised Progesterone, Including Prometrium
If a woman has a uterus and uses systemic oestrogen, she will usually also need progesterone to protect the lining of the womb.
Micronised progesterone passes into breast milk in small amounts. The amount the baby is likely to receive appears to be very low, and the available studies have not identified harmful effects in breastfed babies.
However, direct research on Prometrium as part of HRT during breastfeeding remains limited. Product information may therefore say that it is not indicated during breastfeeding.
This does not necessarily mean that progesterone has been shown to be harmful. It usually means there is not enough direct research for the manufacturer to recommend it routinely.
Its use should be discussed individually with the prescriber.
Oral micronised progesterone may cause:
Drowsiness
Dizziness
Vivid dreams
Next-day tiredness
It is usually taken at night.
Do not use oestrogen without the prescribed progesterone if you still have a uterus.
Progesterone used as part of HRT does not provide reliable contraception.
Low-Dose Vaginal Oestrogen
Breastfeeding can cause significant vaginal and urinary symptoms because oestrogen levels are naturally low.
Symptoms may include:
Vaginal dryness
Burning or irritation
Pain during sex
Vulval discomfort
Urinary urgency
Recurrent urinary infections
Discomfort around a tear, episiotomy or scar
These symptoms may first be treated with:
Vaginal moisturisers
Lubricants
Pelvic-floor treatment
Treatment of infection or vulval skin conditions
Gentle perineal and scar care
If symptoms persist, low-dose vaginal oestrogen can often be considered.
Vaginal oestrogen works mainly within the vaginal and urinary tissues. Much less reaches the rest of the body compared with systemic HRT.
Absorption is not zero, and small amounts may enter breast milk. However, low-dose vaginal treatment is generally considered compatible with breastfeeding when clinically needed.
Use the lowest effective dose and observe milk supply.
There is no reliable “perfect time” to use vaginal oestrogen around feeding. Milk levels can peak at different times in different women. It is better to use the prescribed low-dose treatment consistently than to try to time every dose around a feed.
What About Testosterone?
There is much less evidence about testosterone treatment during breastfeeding.
The limited information available has not shown clear harm to breastfed babies at low maternal doses. Testosterone is also poorly absorbed when swallowed, so the small amount a baby might receive through breast milk is unlikely to be well absorbed.
However:
High doses may reduce milk production
Testosterone gel can transfer directly to the baby through skin contact
There is limited safety information for the doses used in women
Testosterone should therefore not be the first treatment considered while breastfeeding.
Before considering testosterone, other causes of low libido should be addressed, including:
Low oestrogen
Vaginal pain or dryness
Exhaustion and poor sleep
Low mood or anxiety
Relationship difficulties
Thyroid problems
Iron deficiency
Medication side effects
If testosterone is prescribed:
Never apply it to the breasts
Do not apply it where the baby may touch
Wash your hands after application
Allow the area to dry
Cover the application site before handling the baby
HRT Does Not Prevent Pregnancy
Ovulation may return before the first period.
HRT is not contraception, and progesterone used as part of HRT does not reliably prevent pregnancy.
Breastfeeding is considered reliable contraception only when all the following apply:
The baby is under six months old
Breastfeeding is exclusive or almost exclusive
The baby feeds frequently during the day and night
Periods have not returned
If pregnancy is not desired, discuss a breastfeeding-compatible contraceptive method with your doctor.
What Should Be Monitored?
If HRT is started while breastfeeding, monitor:
Breast fullness and milk production
The baby’s feeding pattern
Wet nappies
Whether the baby appears satisfied after feeds
The baby’s weight gain
The mother’s symptom improvement
Vaginal bleeding
Medication side effects
Any symptoms suggesting a blood clot
A lactation consultant can help assess feeding and milk transfer if there are concerns.
When to Seek Medical Advice
Seek advice promptly if:
Milk production clearly falls
The baby has fewer wet nappies
The baby is persistently unsettled after feeding
The baby is not gaining weight
You develop unexpected or heavy vaginal bleeding
You develop a painful or swollen leg
You experience sudden chest pain or breathlessness
You develop a severe headache, weakness, speech difficulty or visual disturbance
Your mood deteriorates or you have intrusive thoughts or thoughts of self-harm
Key Take-Home Messages
Breastfeeding and HRT are not automatically incompatible.
The main concern with systemic oestrogen is a possible reduction in milk supply.
The first six weeks after birth require particular caution.
Transdermal oestradiol is generally preferred over oral oestrogen when systemic treatment is necessary.
Micronised progesterone appears to result in low infant exposure, but direct HRT evidence remains limited.
Low-dose vaginal oestrogen can often be considered for persistent vaginal and urinary symptoms.
Testosterone requires greater caution because breastfeeding safety data are limited.
HRT does not provide contraception.
The mother’s wellbeing matters too. Significant symptoms should not be dismissed simply because she is breastfeeding.
Treatment should be personalised and reviewed alongside the baby’s feeding and growth.
References
Drugs and Lactation Database (LactMed). https://www.ncbi.nlm.nih.gov/books/NBK501721/?utm Updated January 2026.
The Breastfeeding Network. https://www.breastfeedingnetwork.org.uk/factsheet/hrt-hormones-menopause-and-breastfeeding/?utm
Pinheiro E, et al. Transdermal Estradiol Treatment during Breastfeeding: Maternal and Infant Serum Concentrations. Breastfeeding Medicine. 2016;11:50-54.
Faculty of Sexual and Reproductive Healthcare. UK Medical Eligibility Criteria for Contraceptive Use.
Important Information
This leaflet provides general educational information only and does not replace personalised medical advice.
The decision to use HRT while breastfeeding should be individualised and made through shared decision-making. It should take account of the mother’s symptoms and medical history, the baby’s age and health, milk supply, feeding goals and the benefits and risks of each treatment.
Purity Health Menopause & Wellbeing Centre
Dr Purity Carr | GP | Menopause Doctor
Personalised, evidence-based care.
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