Ketamine Therapy and Breastfeeding: What the Current Research Shows

Written By Demi Lucas

Writing this post July of 2026 and Ketamine is having a moment in perinatal mental health. As more mothers seek fast-acting relief from treatment-resistant depression, postpartum depression, and anxiety, I'm getting more questions about whether ketamine therapy and breastfeeding can coexist. This is a nuanced one, so let's walk through what the research actually shows, and where the honest gaps still are.

Why This Question Is Coming Up More

Ketamine has been used safely as a surgical anesthetic for over 50 years, including during cesarean deliveries and postpartum procedures. What's newer is its use, often as IV infusions, intramuscular injections, or the intranasal form esketamine (brand name Spravato), specifically to treat depression that hasn't responded to standard antidepressants. As postpartum depression treatment has expanded to include ketamine, more breastfeeding mothers are facing this decision without a lot of clear, centralized guidance.

What We Know About Ketamine Itself

The Drugs and Lactation Database (LactMed), maintained by the National Institute of Child Health and Human Development, is one of the most trusted clinical references for medication safety during lactation. Its current entry on ketamine is relatively reassuring: ketamine and its active metabolite transfer into milk at very low levels, and because ketamine has low oral bioavailability, an infant absorbs only a small fraction of what they're exposed to even when it is present in milk.

That reassurance is backed by actual data on relative infant dose (RID), which is the standard way researchers measure how much of a medication an infant receives relative to the mother's dose. A drug is generally considered compatible with breastfeeding when its RID is under 10 percent. In a study of four breastfeeding women who received intramuscular ketamine, the RID was calculated at roughly 0.65 percent at a 0.5 mg/kg dose and 0.77 percent at a 1 mg/kg dose, well under that threshold. A separate retrospective review of 298 mother-infant pairs, where mothers received ketamine for postpartum tubal ligation, found no differences in infant weight loss or phototherapy needs regardless of whether mothers received lower or higher doses.

Timing also matters. Research indicates that ketamine levels in breast milk peak roughly 3 to 4 hours after dosing. The Massachusetts General Hospital Center for Women's Mental Health, a leading clinical authority on perinatal psychiatric medication, notes that avoiding breastfeeding for 6 to 12 hours after a single dose can markedly reduce infant exposure, and recommends that any breastfeeding mother using ketamine be monitored closely for infant sedation and poor feeding, given how limited the overall data set still is.

Esketamine (Spravato) Is a Different Conversation

This is the distinction I most want mothers to understand: ketamine and esketamine are not interchangeable when it comes to lactation safety data, even though they're chemically related.

Esketamine is FDA-approved specifically for treatment-resistant depression and is administered intranasally in a monitored clinical setting. The InfantRisk Center at Texas Tech University Health Sciences Center, one of the country's leading resources on medication safety during lactation, is notably more cautious here. Because of limited information on how esketamine transfers into milk and its potential effects on breastfed infants, InfantRisk states plainly that it is not currently possible to conclude esketamine is safe during breastfeeding. Like ketamine, it likely transfers into milk to some degree, and InfantRisk suggests that a waiting period of approximately 8 hours after dosing may meaningfully reduce infant exposure, but this is a more conservative, less established recommendation than what exists for ketamine itself.

If you're considering esketamine specifically, rather than IV or IM ketamine, that distinction should be part of the conversation with your prescriber.

What This Means in Practice

A few things I want every mother weighing this decision to walk away understanding:

The data we have is reassuring but still limited. Most of the RID and safety data comes from small studies, often involving single or low-frequency dosing in surgical or short-term contexts, not necessarily the repeated infusion schedules some mothers use for depression treatment. Researchers themselves describe ketamine and breastfeeding as an emerging area, not a settled one.

Monitoring the infant matters, regardless of which option you choose. Every major source reviewed here, LactMed, MGH, and InfantRisk, converges on the same practical guidance: watch for sedation, poor feeding, or poor weight gain in the breastfed infant, and loop in your pediatrician if anything seems off.

Pumping and storing milk ahead of a scheduled dose is a reasonable strategy. Since ketamine infusions for depression are often given on a set schedule, some mothers choose to pump extra milk beforehand and simply wait out the 6-to-12-hour window before resuming breastfeeding, rather than avoiding treatment altogether or stopping breastfeeding.

This is a risk-benefit conversation, not an automatic contraindication. Current literature frames ketamine use during breastfeeding as a case-by-case clinical decision, weighing the real risks of untreated maternal depression against the currently low, but not zero, level of infant exposure. Untreated postpartum depression carries its own well-documented risks to both mother and infant, and that has to be part of the equation too.

Who Should Be Part of This Decision

This isn't a decision to make from a blog post, mine included. It should involve your prescribing psychiatrist or ketamine provider, your pediatrician, and ideally an IBCLC who can help you think through practical timing, pumping strategy, and infant monitoring if you decide to move forward with treatment while breastfeeding.

If you're navigating this decision and want support building a plan around it, I'm glad to help you think it through alongside your medical team.

If you're weighing a medication or treatment decision while breastfeeding, I offer in-home consultations across Northern Virginia and virtual consultations nationwide. Contact Kindred Milk to talk through your specific situation.

If you or someone you know is struggling with perinatal mental health disorders, you can access free 24/7 support through Postpartum Support International: HERE

References

  • Ketamine. Drugs and Lactation Database (LactMed). National Institute of Child Health and Human Development. Last revised February 2026. https://www.ncbi.nlm.nih.gov/books/NBK500566/

  • Esketamine and Breastfeeding. InfantRisk Center, Texas Tech University Health Sciences Center. https://www.infantrisk.com/content/esketamine-breastfeeding

  • Wolfson, P., Cole, R., Lynch, K., Yun, C., Wallach, J., Andries, J., Whippo, M. The Pharmacokinetics of Ketamine in the Breast Milk of Lactating Women: Quantification of Ketamine and Metabolites. Journal of Psychoactive Drugs.

  • You Asked: Is Ketamine an Option for the Treatment of Breastfeeding Women? MGH Center for Women's Mental Health. https://womensmentalhealth.org/posts/ketamine-and-breastfeeding/

  • Ketamine and Perinatal Mental Health: Problems and Potentials. PMC.https://pmc.ncbi.nlm.nih.gov/articles/PMC11994625/

Demi Lucas
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