Antihistamines While Breastfeeding: Zyrtec, Claritin, Allegra and Benadryl

Itchy eyes, a runny nose and hives don’t pause because you’re nursing. The good news is that you usually don’t have to choose between feeling better and breastfeeding: some antihistamines have been studied enough to be called good choices, and the amount that reaches your milk is small.

This guide covers the allergy medicines people ask about most (Zyrtec, Claritin, Allegra and Benadryl), which ones are generally preferred, and the two things worth watching: drowsiness in your baby and your milk supply. It’s general information, so check your own medicine and your baby’s situation with a doctor or pharmacist. For the wider picture, see our hub on what’s safe while breastfeeding.

Which antihistamines are preferred while breastfeeding?

The NHS Specialist Pharmacy Service (SPS) says cetirizine and loratadine are the preferred antihistamines when breastfeeding a healthy, full-term baby, and that chlorphenamine (called chlorpheniramine in the US) is the preferred sedating one. Here is how the main options compare.

Antihistamine	Drowsiness	What the sources say
Cetirizine (Zyrtec)	Less sedating	Preferred by SPS; LactMed says small occasional doses are acceptable
Loratadine (Claritin)	Non-sedating	Preferred by SPS; LactMed says no adverse effects expected in babies
Fexofenadine (Allegra)	Non-sedating	LactMed expects no problems; SPS says use with caution because data are limited
Diphenhydramine (Benadryl)	Sedating	LactMed: small, occasional doses (25 mg or less) are not expected to cause problems
Chlorpheniramine	Sedating	LactMed: small, occasional doses (2 to 4 mg) are acceptable
Hydroxyzine	Sedating	LactMed: other agents are preferred, especially with a newborn or preterm baby

Zyrtec (cetirizine) while breastfeeding

LactMed says small, occasional doses of cetirizine are acceptable during breastfeeding and that international guidelines recommend it as an acceptable choice if you need an antihistamine. The NHS calls it one of the best choices and says only very small amounts get into breast milk. MotherToBaby adds that it’s thought less likely to cause drowsiness than some other antihistamines.

You may notice that the over-the-counter Zyrtec Allergy label says breastfeeding is not recommended, and MotherToBaby points out the same label wording. It is more cautious than the clinical sources above, so it’s worth a quick word with your pharmacist rather than a reason to panic.

LactMed also warns that larger doses or longer use may cause drowsiness in your baby or reduce milk supply, particularly before breastfeeding is well established.

Claritin (loratadine) while breastfeeding

LactMed says that because loratadine is non-sedating and reaches milk in low levels, maternal use would not be expected to cause adverse effects in breastfed babies. It also notes that the British Society for Allergy and Clinical Immunology recommends the lowest dose as a preferred choice. SPS mentions a survey of 51 mothers that reported two cases of minor infant sedation and one case of decreased milk production, so effects are possible but uncommon.

Allegra (fexofenadine) while breastfeeding

Opinions differ slightly here. LactMed says fexofenadine would not be expected to cause adverse effects because it’s non-sedating and reaches milk in low levels. SPS says to use it with caution because the evidence is very limited and comes from its parent drug, and that cetirizine or loratadine are preferred. The NHS says you can take it if you need to, although other antihistamines might be better. If you already take Allegra and do well on it, ask your doctor whether to stay on it or switch.

Benadryl and other sedating antihistamines

Diphenhydramine (Benadryl), chlorpheniramine and hydroxyzine can make your baby sleepy and, in larger or repeated doses, may lower supply. LactMed says a single bedtime dose after the last feeding of the day may be enough for many women and minimizes any effect, and that the non-sedating antihistamines are preferred alternatives. Our guide to Benadryl while breastfeeding covers it in more detail.

SPS notes that younger, exclusively breastfed babies are at greater risk of side effects, and that NICE advises avoiding bed-sharing when a sedating medicine has been used. So if you take one, a dose after the last feeding of the day is the approach LactMed describes, and it’s safest not to share a bed with your baby afterward.

Do antihistamines lower milk supply?

Probably not at normal doses once breastfeeding is established. SPS says antihistamines at normal therapeutic doses are unlikely to affect milk production, but that occasional cases of reduced supply have been reported with loratadine and cetirizine. LactMed lists the situations to be careful in: larger doses, longer use, before lactation is well established, and in combination with a sympathomimetic such as pseudoephedrine.

That last point matters for allergy products sold with a “-D” suffix. The DailyMed labels for Zyrtec-D and Claritin-D 12 hour list pseudoephedrine 120 mg as an active ingredient. MotherToBaby also says that decongestants and antihistamines taken together may have extra ability to reduce milk supply. See our guide to Sudafed and pseudoephedrine while breastfeeding for the evidence on that decongestant, and cold medicine while breastfeeding for how to read multi-ingredient labels.

Nasal sprays and eye drops

SPS says intranasal or topical antihistamines are preferred options if they suit your symptoms, because very little gets into your bloodstream or milk. LactMed says small occasional doses of azelastine nasal spray are not expected to cause problems, though some babies might reject the breast because of the bitter taste, and that the oral non-sedating antihistamines are preferred alternatives. LactMed’s fluticasone entry adds that expert opinion considers inhaled, nasal and oral corticosteroids acceptable during breastfeeding, so a steroid nasal spray is another option to discuss with your pharmacist.

For antihistamine eye drops, LactMed suggests pressing on the tear duct at the corner of your eye for 1 minute or more, then wiping away the excess, to reduce how much reaches your milk.

Practical tips

• Use the lowest effective dose for the shortest time, as SPS advises.
• Choose a single-ingredient product and read the “Active ingredients” box, not the brand name.
• Watch your baby for sleepiness, irritability and feeding changes after you start a new medicine.
• Tell your pharmacist about any prescription medicines you take.
• Pain or fever as well? See ibuprofen and Tylenol while breastfeeding.

When to call a doctor or lactation consultant

Contact your baby’s doctor if your baby is unusually sleepy, hard to wake for feeds, falls asleep during feeds, feeds less well than usual or seems irritable, or if you’re worried about any other symptom. SPS lists these as the signs to watch for, along with poor weight gain. The NHS advises that you keep taking your medicine and keep breastfeeding as usual until you’ve had advice about your baby’s symptoms.

Talk to a pharmacist or doctor before taking any antihistamine if your baby is a newborn, was born early or is unwell, since the guidance above is for healthy, full-term babies. If your supply seems to drop after starting a medicine, an IBCLC can help; our breastfeeding support page lists where to find one.