Can you take tolbutamide 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.
Tolbutamide is no longer marketed in the United States. It is excreted into breastmilk in small amounts that should cause no harm to the breastfed infant. Monitor breastfed infants for signs of hypoglycemia such as jitteriness, excessive sleepiness, poor feeding, seizures cyanosis, apnea, or hypothermia. If there is concern, monitoring of the breastfed infant's blood glucose is advisable during maternal therapy with hypoglycemic agents.
Quoted from Tolbutamide — Drugs and Lactation Database (LactMed®), National Institute of Child Health and Human Development, revised May 15, 2026.
How much tolbutamide gets into breastmilk
Maternal Levels. In 2 women who were 3 days postpartum, milk levels were measured 4 hours after ingestion of a 500 mg dose of tolbutamide. Milk levels averaged 18 mg/L in one and 3 mg/L in the other.
Infant Levels. Relevant published information was not found as of the revision date.
What has been seen in breastfed infants
Relevant published information was not found as of the revision date.
Effects on milk supply
Relevant published information was not found as of the revision date.
Frequently asked questions
Can you take tolbutamide while breastfeeding?
Tolbutamide is no longer marketed in the United States. 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.
Does tolbutamide pass into breastmilk?
LactMed's measured drug levels for tolbutamide are quoted in full on this page, under "How much gets into breastmilk".
Do I need to pump and dump after taking tolbutamide?
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 tolbutamide
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.