Biologics and Breastfeeding

What the evidence shows about biologic medications during lactation

⚠️ Important

This page provides general educational information. All decisions about biologic use during breastfeeding must be made with your rheumatologist, gastroenterologist, OB/GYN, and a lactation consultant.

Key Takeaways

Most large-molecule biologics transfer minimally into breast milk
Even when present in milk, large proteins are largely degraded in the infant's GI tract and poorly absorbed systemically
JAK inhibitors (small molecules) have different properties — discuss specifically with your specialist
The benefit of controlling your autoimmune disease must be weighed against any theoretical infant risk

What the Evidence Shows

Large protein biologics (monoclonal antibodies such as Humira, Skyrizi, Dupixent, Entyvio, and others) have high molecular weights that limit transfer into breast milk. Studies measuring drug levels in breast milk and infant serum typically show very low to undetectable levels in nursing infants exposed to these medications. Additionally, the infant's digestive system breaks down proteins before significant systemic absorption can occur.

JAK inhibitors (Rinvoq, Xeljanz) are small molecules with different pharmacokinetic properties that may result in higher milk transfer. Limited data is available, and most manufacturers recommend avoiding use during breastfeeding. Consult your specialist for individualized guidance.

Available data suggests that adalimumab (Humira) transfers into breast milk in very small amounts and infant systemic exposure is expected to be minimal due to poor oral bioavailability of large proteins. Many specialists consider continued use of Humira during breastfeeding acceptable when the benefit to the mother outweighs potential risks. Always discuss this decision with your rheumatologist and OB/GYN.

Limited data is available for dupilumab (Dupixent) during breastfeeding. Given its large molecular weight and mechanism of action, transfer into breast milk and infant absorption are expected to be low. Discuss individual risks and benefits with your dermatologist or allergist and your infant's pediatrician.

JAK inhibitors (Rinvoq/upadacitinib, Xeljanz/tofacitinib) are small molecules that may transfer into breast milk at higher levels than large-molecule biologics. Most product labels recommend avoiding use during breastfeeding due to limited safety data. Discuss alternatives with your specialist if you plan to breastfeed.

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📚 Sources & Further Reading

Content developed with reference to leading health organizations, peer-reviewed research, and FDA prescribing information.

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Biologics During LactationNIH/NCBI

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Biologics & BreastfeedingMotherToBaby

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Breast Milk CompositionWikipedia

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Pharmacokinetics in Special PopulationsFDA

Medical Disclaimer: Educational content reviewed by the BiologicHealthPlus Clinical Team. Consult your healthcare provider for personalized advice. Last reviewed: August 2026.

Medical Disclaimer: General educational information only. Consult your healthcare providers for individualized guidance. Last updated: July 2026.