Psychiatric Medications While Breastfeeding: What to Ask
Many psychiatric medications, including most antidepressants, can be used while breastfeeding. Sertraline and paroxetine reach only low levels in breast milk, and most authoritative reviewers consider them preferred antidepressants during breastfeeding, according to the NIH's LactMed database. Guidance from the Academy of Breastfeeding Medicine favors continuing an antidepressant that kept you well during pregnancy.
The decision weighs three things: the benefits of breastfeeding, your need for the medicine, and how much reaches the baby. The best questions to ask are how much of the drug gets into milk, what effects have been reported in infants, and how your baby's age and health change that picture. Breastfeeding is never a reason to stop a psychiatric medicine on your own.
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How lactation safety is judged
Two tools do most of the work. The first is LactMed, a free database from the National Institutes of Health that summarizes published data on drug levels in milk and in infants, effects on breastfed babies, and effects on milk supply, drug by drug. It is written for clinicians but readable by patients.
The second is the relative infant dose (RID): the amount of a drug a baby receives through milk, expressed as a percentage of the parent's weight-adjusted dose. An RID below 10% is generally considered compatible with breastfeeding. RID is a measure of exposure, not of harm, so it is one input rather than a verdict.
Why the baby's age and health matter
Your baby's age and health change the picture. LactMed notes that preterm infants with impaired metabolism might accumulate sertraline, rarely, and that for several drugs extra caution applies while nursing a newborn or preterm infant. A medicine that is easy to use with a healthy 4-month-old may need closer watching with a 2-week-old born early, and your baby's pediatric clinician should know what you take.
Antidepressants and breastfeeding
| Medicine | Milk levels | What LactMed or the label says |
|---|---|---|
| Sertraline | Low; usually not detected in infant serum | Considered a preferred antidepressant by most authoritative reviewers; no developmental effects found in infants followed up to age 5 |
| Paroxetine | Low; not detected in most infants tested | Considered one of the preferred antidepressants; occasional mild infant side effects reported |
| Fluoxetine | Higher than most SSRIs; long-acting metabolite detectable in most infants early on | Not a reason to stop breastfeeding if needed; lower-excretion drugs may be preferred for newborns if starting fresh |
| Bupropion | Low at usual doses | Little data in newborns and case reports of possible seizures; another drug may be preferred for newborns |
| Zuranolone | Low; mean RID 0.357% in a 14-woman study | Not a reason to stop breastfeeding; monitor for infant sedation |
Sertraline
The sertraline label summarizes a pooled analysis of 53 mother-infant pairs: exclusively breastfed infants had on average 2% of their mothers' sertraline serum levels, ranging from 0% to 15%, and no adverse reactions were observed. LactMed adds that no adverse developmental effects have been found in infants followed for up to 5 years. The Academy of Breastfeeding Medicine suggests sertraline as a first choice for a mother who has not taken an antidepressant before.
Paroxetine
LactMed describes low milk levels and lists paroxetine among the preferred antidepressants during breastfeeding. The label notes reports of agitation, irritability, poor feeding and poor weight gain in infants exposed through milk, and advises monitoring. LactMed points out that mild side effects were seen especially in infants also exposed in the third trimester, when the contribution of milk is unclear.
Fluoxetine
Fluoxetine passes into milk in larger amounts than most SSRIs, and its long-acting metabolite can be detected in most breastfed infants during the first 2 months. Colic, fussiness and drowsiness have been reported in some infants. Still, if you took fluoxetine during pregnancy or other antidepressants have not worked, LactMed notes that most experts recommend against switching during breastfeeding. Our comparison of fluoxetine vs sertraline covers the broader differences.
Continuing what worked
The Academy of Breastfeeding Medicine's antidepressant protocol says that if a mother responded well to a particular antidepressant before, that drug should be considered first unless there is a reason not to, and that mothers well controlled on an antidepressant during pregnancy should continue the same agent while breastfeeding. Switching purely for lactation means a new drug, new side effects and a chance the new one works less well.
Zuranolone and breastfeeding
Zuranolone (Zurzuvae) is a 14-day oral treatment approved for postpartum depression. In a lactation study in 14 healthy women taking a lower dose for 5 days, zuranolone was present in milk at low levels, with a calculated maximum RID below 1% and a mean RID of 0.357%; milk levels fell below the limit of measurement 4 to 6 days after the last dose. There are no data on effects in breastfed infants and limited data on milk production.
ACOG's 2025 update says pumping and discarding milk through 1 week after the course may be considered because direct infant safety data are lacking, but that this should be weighed against continued breastfeeding through shared decision-making, since the RID is below the 10% threshold. LactMed says zuranolone is not a reason to stop breastfeeding and advises watching the infant for excess sedation, especially in newborns and preterm infants.
One practical point matters more than milk levels. ACOG advises that for at least 12 hours after each dose, patients should not drive or care for their infant alone, including feeding, changing or bathing. That makes a support plan essential before starting. Our guide to postpartum depression treatment options compares zuranolone with SSRIs and therapy.
Mood stabilizers, antipsychotics and anxiety medicines
| Medicine | Summary from LactMed | What monitoring may involve |
|---|---|---|
| Lithium | Milk and infant levels vary widely; not considered an absolute contraindication in healthy full-term infants by most sources | Infant blood tests in some protocols; extra risk if the infant becomes dehydrated |
| Lamotrigine | Monotherapy does not appear to harm growth or development in most infants | Watch for rash, apnea, drowsiness or poor sucking; maternal levels often rise after delivery |
| Quetiapine | Milk doses under 1% of the maternal weight-adjusted dose at up to 400 mg daily | Watch for drowsiness and developmental milestones |
| Lorazepam | Low milk levels and a shorter half-life than many benzodiazepines | Watch for sedation, poor feeding and poor weight gain |
Lithium deserves special attention. LactMed notes that lithium in milk can affect an infant whose elimination is impaired, as with dehydration or in newborns and premature babies, and that maternal levels should be monitored frequently after delivery and the dose reduced as needed. Some investigators recommend periodic infant blood tests for lithium level, kidney function and thyroid function. The FDA-approved lithium label is more cautious than LactMed: it says breastfeeding is not recommended during lithium treatment and, if a woman chooses to breastfeed, the infant should be monitored for signs of toxicity. Our article on lithium monitoring explains what those tests involve.
For lamotrigine, LactMed notes that maternal blood levels often rise after delivery, so the parent's dose may need adjusting regardless of breastfeeding. If an infant develops a rash, LactMed advises stopping breastfeeding until the cause is found.
Protecting sleep is part of the treatment plan
Sleep loss is not just exhausting after a birth. The Academy of Breastfeeding Medicine notes that interrupted sleep is a major trigger for mood symptoms, and suggests arranging for another caregiver to handle one night feeding so the mother can rest. That caregiver can bring the baby to the breast and then take responsibility for settling the baby back to sleep.
A sleep plan works best when it is written down before you are depleted. Elements to discuss with your partner, family and clinicians:
- One protected stretch of sleep each night, with another adult covering at least one feeding.
- Whether pumped or donor milk or formula will be used for that feeding, and how you feel about each option.
- Who takes over, and whom you call, if your sleep or mood changes suddenly.
- Whether any medicine you take is sedating, and who will be awake and responsible for the baby after you take it.
- When to call your prescriber about sleep, rather than adding an over-the-counter sleep aid.
Sleep medicines raise separate questions while caring for an infant; see sleep medications compared and ask before taking anything new.
Watching your baby: what monitoring looks like
For most medicines, monitoring means ordinary attention to how the baby is feeding, sleeping and growing. The Academy of Breastfeeding Medicine advises careful follow-up of infant growth, says routine infant blood levels are not needed without a clinical reason, and encourages the parent's and infant's clinicians to communicate.
| Sign to report to the pediatric clinician | Medicines where LactMed or labels mention it |
|---|---|
| Unusual sleepiness or sedation | Zuranolone, lorazepam, quetiapine, fluoxetine |
| Poor feeding or poor weight gain | Paroxetine, fluoxetine, lorazepam |
| Irritability, agitation, colic or fussiness | Paroxetine, fluoxetine |
| Rash, apnea or poor sucking | Lamotrigine |
| Vomiting, diarrhea or jitteriness | Bupropion combined with an SSRI |
Some SSRI difficulties overlap with pregnancy exposure. LactMed notes that mothers who took an SSRI in pregnancy may have more difficulty breastfeeding, possibly reflecting the illness itself, and may need extra lactation support.
What the evidence does not show
Lactation data are reassuring for several medicines, but they are thinner than most people assume. Much of what is known comes from pooled measurements in dozens of mother-infant pairs, small dedicated studies and case reports, rather than large controlled trials. A few specific gaps are worth knowing:
- Milk supply: the sertraline and paroxetine labels say there are no data on effects on milk production, and the zuranolone label says data are limited.
- Long-term effects: for lithium, LactMed says long-term effects on infants are not certain, though limited data show no obvious problems in growth and development. Long-term follow-up of quetiapine-exposed infants is also limited.
- Direct infant effects: there are no data on zuranolone's effects on breastfed infants, only measurements of how much reaches milk.
- Newborns: for bupropion, there is little reported use in breastfed newborns.
Gaps like these are why monitoring matters and why the advice can differ for a newborn and an older baby. They are not, on their own, reasons to avoid a medicine you need.
When breastfeeding and treatment pull in different directions
FDA labels frame the decision as weighing the developmental and health benefits of breastfeeding against the parent's clinical need for the medicine and any potential effects on the child from the drug or from the untreated condition. Sometimes the medicine that works best for you has limited lactation data, or the logistics of nursing are making sleep and recovery impossible.
Choosing to combine breastfeeding with formula, or to stop breastfeeding, so that you can take the treatment you need is a legitimate decision, not a failure. So is choosing to continue breastfeeding on a medicine with reassuring data. What matters is that the choice is yours, made with accurate information, and that no one pressures you to give up either your treatment or your feeding plan without a real discussion.
Questions to ask your prescriber
- What does LactMed say about this medicine, and what is its relative infant dose?
- Does my baby's age, prematurity or health change the advice?
- Should I continue what I took in pregnancy rather than switch?
- What signs in my baby should prompt a call, and to whom?
- Will you share the plan with my baby's pediatric clinician?
- How do we protect my sleep, and what happens if my mood or sleep changes suddenly?
For free, expert answers about a specific medicine, MotherToBaby can be reached at 866-626-6847 or by text at 855-999-3525. The National Maternal Mental Health Hotline offers free, confidential support 24/7 by call or text at 1-833-852-6262. If you are deciding about medication before delivery, our article on psychiatric medications during pregnancy covers that stage.
How Dr. Lewis's practice can help
The practice's psychiatrists and psychiatric nurse practitioners provide medication management, and its psychotherapists provide therapy. If you are breastfeeding, ask on the free discovery call whether the practice is the right fit for your situation. The drlewis.com article on pregnancy and depression gives background, and psychotherapy at the practice describes the therapy side. If you want a specialist in this life stage, see what a reproductive psychiatrist does. More comparisons are in the Choosing Psychiatric Care guide.
Frequently asked questions
Do I need to pump and dump while taking an antidepressant?
For most antidepressants, no. Sertraline and paroxetine reach low milk levels and are considered preferred options. Pumping and discarding is sometimes discussed for zuranolone, but ACOG frames it as a choice to weigh against continued breastfeeding.
What is a relative infant dose?
It is the dose a baby receives through milk as a percentage of the parent's weight-adjusted dose. Below 10% is generally considered compatible with breastfeeding.
Is it safe to breastfeed while taking lithium?
Sources differ. Most sources reviewed by LactMed do not consider it an absolute contraindication in healthy full-term infants, but the FDA label says breastfeeding is not recommended, and any decision requires a plan for monitoring the infant and your own levels. Discuss it with your prescriber and the baby's pediatric clinician.
Should I switch from fluoxetine to sertraline because I am breastfeeding?
Not automatically. If you took fluoxetine in pregnancy or other drugs have not worked, most experts recommend against changing during breastfeeding. Any change is your prescriber's decision with you.
Can antidepressants reduce my milk supply?
Data are limited; the sertraline label says there are no data on its effects on milk production. If supply drops, involve a lactation consultant and tell your prescriber.
Can I take a sleep aid while breastfeeding?
Ask your prescriber first. Many sleep aids are sedating, and the question includes who is caring for the baby while you sleep. See our sleep medications comparison.
Sources
- Sertraline. Drugs and Lactation Database (LactMed), NICHD/NIH, 2026. ncbi.nlm.nih.gov
- Paroxetine. Drugs and Lactation Database (LactMed), NICHD/NIH, 2026. ncbi.nlm.nih.gov
- Fluoxetine. Drugs and Lactation Database (LactMed), NICHD/NIH, 2026. ncbi.nlm.nih.gov
- Lithium. Drugs and Lactation Database (LactMed), NICHD/NIH, 2026. ncbi.nlm.nih.gov
- Lamotrigine. Drugs and Lactation Database (LactMed), NICHD/NIH, 2026. ncbi.nlm.nih.gov
- Lorazepam. Drugs and Lactation Database (LactMed), NICHD/NIH, 2026. ncbi.nlm.nih.gov
- ACOG Clinical Practice Update: Zuranolone and Brexanolone for the Treatment of Postpartum Depression. Obstetrics & Gynecology (ACOG), 2025. doi.org
- Zurzuvae (zuranolone) prescribing information. DailyMed / U.S. FDA label, 2026. dailymed.nlm.nih.gov
- Zoloft (sertraline) prescribing information. DailyMed / U.S. FDA label, 2023. dailymed.nlm.nih.gov
- Paroxetine tablets prescribing information. DailyMed / U.S. FDA label, 2026. dailymed.nlm.nih.gov
- ABM Clinical Protocol #18: Use of Antidepressants in Breastfeeding Mothers. Breastfeeding Medicine (Academy of Breastfeeding Medicine), 2015. pmc.ncbi.nlm.nih.gov
- Zuranolone. Drugs and Lactation Database (LactMed), NICHD/NIH, 2025. ncbi.nlm.nih.gov
- Quetiapine. Drugs and Lactation Database (LactMed), NICHD/NIH, 2026. ncbi.nlm.nih.gov
- Bupropion. Drugs and Lactation Database (LactMed), NICHD/NIH, 2026. ncbi.nlm.nih.gov
- About Us. MotherToBaby (Organization of Teratology Information Specialists), 2026. mothertobaby.org
- National Maternal Mental Health Hotline: Frequently Asked Questions. Health Resources and Services Administration (HHS), 2026. mchb.hrsa.gov
- Lithium carbonate capsules prescribing information. DailyMed / U.S. FDA label, 2026. dailymed.nlm.nih.gov
Educational information, not medical, tax or legal advice. Decisions about diagnosis, medication and treatment belong with a clinician who knows your history.
The information provided on this blog is for educational and informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.
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