Can you take hydrochlorothiazide while breastfeeding?
What LactMed says
The National Library of Medicine’s own summary, quoted in full. We do not write a verdict of our own on this question, and we do not compress theirs into a label.
Hydrochlorothiazide doses of 50 mg daily or less are acceptable during lactation. Intense diuresis with large doses may decrease breastmilk production.
Quoted from Hydrochlorothiazide — Drugs and Lactation Database (LactMed®), National Institute of Child Health and Human Development, revised September 15, 2025.
What LactMed would consider instead
LactMed ends this record by naming the drugs it would consider in place of hydrochlorothiazide. Whether any of them fits depends on what you are treating — this is the database’s list, not a recommendation from us.
How much hydrochlorothiazide gets into breastmilk
Maternal Levels. In a mother who was 28 days postpartum, hydrochlorothiazide reached a peak milk level of about 275 mcg/L at about 3 hours after a 50 mg oral dose. The infant received a daily dosage of about 2% of the mother's weight-adjusted dose.
Infant Levels. Hydrochlorothiazide was not detectable (<20 mcg/L) in the serum of a 28-day-old breastfed infant at about 2 and 11 hours after the mother's dose.
What has been seen in breastfed infants
No electrolyte abnormalities were noted in one 28-day-old infant who was breastfed since birth while his mother was taking oral hydrochlorothiazide 50 mg daily.
Effects on milk supply
Hydrochlorothiazide in dosages of 100 mg daily in the morning and 50 mg in the afternoon or 50 mg twice daily have been used to successfully to suppress lactation at various times postpartum. Intense diuresis with thiazides and thiazide-like diuretics, fluid restriction and breast binding have been used to suppress postpartum lactation. The added contribution of the diuretic to these measures, which are effective in suppressing lactation, has not been studied. There are no data on the effects of diuretics on established, ongoing lactation.
In a pilot study of the treatment of patients with postpartum hypertension, patients were randomized to either 12.5 mg hydrochlorothiazide plus 10 mg of lisinopril (n = 31) or 30 mg of nifedipine (n = 36) daily. The dosages could be increased to 12.5 mg hydrochlorothiazide plus 20 mg of lisinopril and then to 25 mg hydrochlorothiazide with 20 mg lisinopril. Nifedipine dosage was increased in 30 mg increments to a maximum daily dose of 120 mg daily. At discharge, 21 hydrochlorothiazide-lisinopril mothers (70%) were breastfeeding while19 nifedipine mothers (53%) were breastfeeding.
Frequently asked questions
Can you take hydrochlorothiazide while breastfeeding?
Hydrochlorothiazide doses of 50 mg daily or less are acceptable during lactation. The full record is quoted on this page, and the decision is one to make with the person who prescribed it — LactMed itself states it is not a substitute for professional judgement.
What can I take instead of hydrochlorothiazide while breastfeeding?
LactMed lists Chlorothiazide as alternate drugs to consider. That is the database's own list for this drug — whether any of them suits you depends on what you are treating.
Does hydrochlorothiazide pass into breastmilk?
LactMed's measured drug levels for hydrochlorothiazide are quoted in full on this page, under "How much gets into breastmilk".
Do I need to pump and dump after taking hydrochlorothiazide?
LactMed does not frame its records that way — it reports measured drug levels in milk and what has been observed in breastfed infants, which is what this page quotes. "Pump and dump" advice for a specific drug and dose should come from your clinician or a pharmacist, not from a general rule.
More on hydrochlorothiazide
LactMed states that the information it presents is not a substitute for professional judgement, and that you should consult your healthcare provider for breastfeeding advice related to your particular situation. Nothing on this page is medical advice.