Cetirizine is Safe for Breastfeeding
Cetirizine is compatible with breastfeeding and poses minimal risk to the infant, with very low transfer into breast milk and no reported adverse effects in breastfed infants. 1, 2
Evidence Supporting Safety
The most recent and highest quality evidence demonstrates that cetirizine transfer into breast milk is minimal:
- The relative infant dose (RID) is approximately 1.9%, well below the 10% safety threshold used to determine compatibility with breastfeeding 2
- Maximum cetirizine concentrations in breast milk average 41.0 μg/L, occurring approximately 2.4 hours after maternal intake 2
- The absolute infant dose is estimated at only 2.5 μg/kg per day 2
- A 2025 population pharmacokinetic study confirmed the mean RID of 1.99%, with the highest RID being only 3.36% at peak maternal concentrations 3
Clinical Recommendations
Among antihistamines, loratadine or cetirizine should be preferred during breastfeeding as they have been most extensively studied. 4
Practical Guidance:
- Breastfeeding can continue normally without interruption when taking cetirizine 1, 2
- No adverse effects have been reported in breastfed infants exposed to cetirizine 1, 2
- To minimize infant exposure further, mothers can take cetirizine immediately after breastfeeding 5
Important Caveats
Renal Impairment:
- In moderate renal impairment (creatinine clearance 10-20 mL/min), the cetirizine dose should be halved 4
- Cetirizine should be avoided entirely in severe renal impairment (creatinine clearance <10 mL/min) 4
Theoretical Concerns:
- Antihistamines may theoretically reduce milk production, though this has not been demonstrated clinically with cetirizine 4
- Mothers should monitor infants for paradoxical CNS stimulation, though this has not been reported with cetirizine specifically 5
Reconciling Conflicting Information
While the FDA label states cetirizine is "not recommended" during breastfeeding 6, this recommendation is outdated and contradicted by multiple recent high-quality human lactation studies from 2021-2024 demonstrating safety 1, 3, 2. The European Respiratory Society guidelines from 2020 support cetirizine use during breastfeeding 4, and systematic review data confirm its compatibility 7.