Breastfeeding & Drug Safety

Search medications using Hale lactation risk categories (L1–L5). Get evidence-based guidance on which drugs are safe while nursing.

Important
Do not stop nursing or taking necessary medications without consulting your pediatrician or healthcare provider. This information is for educational purposes only.

Hale Lactation Risk Categories

L1

Safest

Drug which has been taken by a large number of breastfeeding mothers without any observed increase in adverse effects in the infant.

L2

Safer

Drug which has been studied in limited numbers of breastfeeding mothers without an increase in adverse effects in the infant.

L3

Moderately Safe

There are no controlled studies in breastfeeding women, but evidence suggests the drug poses a minimal risk to the infant.

L4

Possibly Hazardous

There is positive evidence of risk to a breastfed infant or a medication with no experience in breastfeeding women.

L5

Contraindicated

Studies in breastfeeding mothers have demonstrated that there is significant and documented risk to the infant based on human experience.

About Milk Transfer

Most medications pass into breast milk in small amounts. The infant's dose is typically far lower than the mother's. Factors like drug size, lipid solubility, and binding affect transfer. Many drugs are effectively broken down by infant stomach acid or poorly absorbed.

Your pediatrician can assess whether a specific medication poses clinically significant risk.

Common Questions

Pain Relievers (Acetaminophen, Ibuprofen)

Acetaminophen (L1) and ibuprofen (L2) are generally safe. Avoid naproxen (L3) and aspirin (L3) for long-term use. Check with your pediatrician for dosage.

Antibiotics

Penicillins and cephalosporins (L1/L2) are safe. Tetracyclines (L3/L4) may discolor infant teeth. Fluoroquinolones vary (L2–L3). Discuss specific antibiotic with your doctor.

Antidepressants (SSRIs)

Sertraline and paroxetine (L2) are safer choices. Fluoxetine may accumulate (L2/L3). Discuss depression treatment with your provider—untreated depression harms bonding.

Birth Control (Hormonal)

Progestin-only pills (L1) are safest while breastfeeding. Combined hormonal contraceptives (L2/L3) may reduce milk supply. Discuss timing and type with your provider.

Allergy Medications

Cetirizine (Zyrtec, L1) and loratadine (Claritin, L1) are safe. Avoid first-generation antihistamines (L2/L3) due to infant drowsiness. Decongestants may reduce supply.

About LactMed

LactMed is the National Library of Medicine's database of drugs and lactation. It provides detailed information on medication effects on breastfed infants and nursing mothers. Many healthcare providers consult LactMed for evidence-based recommendations. You can access it at lactmed.nlm.nih.gov.

Tips for Safe Medication Use While Breastfeeding

Take medication shortly after nursing

Peak milk concentration occurs 1–3 hours post-dose for most drugs.

Request the lowest effective dose

Ask your provider if a lower dose or shorter duration is possible.

Avoid long-term or high-dose drugs when safer alternatives exist

Work with your provider to select medications with best safety profiles.

Monitor your infant for unusual signs

Drowsiness, poor feeding, rashes, or behavioral changes warrant discussion with your pediatrician.

Need More Help?

Consult your pediatrician, lactation consultant, or pharmacist for personalized medication advice while breastfeeding.