The maximum recommended dose of Allegra (fexofenadine) for adults is 180 mg per day. You can take this as a single 180 mg tablet once daily or as 60 mg twice a day, for a total of 120 mg. Both schedules are used for seasonal allergies and chronic hives, though the 180 mg once-daily option is the most common over-the-counter format. Taking more than 180 mg in 24 hours is not recommended.
Adult Dosing Options
Allegra comes in two main strengths for adults and children 12 and older. The 180 mg tablet is designed to be taken once every 24 hours. The 60 mg tablet is taken every 12 hours, meaning two tablets per day. Both options deliver effective allergy relief for hay fever symptoms like sneezing, runny nose, and itchy eyes, as well as for chronic hives.
The dosing is the same regardless of whether you’re treating seasonal allergies or hives. There is no situation where the standard labeling recommends exceeding 180 mg in a single day for either condition.
Children’s Dosing by Age
Children between 2 and 11 years old use a liquid suspension rather than adult tablets. The recommended dose is 5 mL (one teaspoon) every 12 hours, with a maximum of 10 mL in 24 hours. Children 12 and older follow the same dosing schedule as adults.
Allegra is not typically recommended for children under 2 without guidance from a pediatrician. If you’re unsure which product to use for a child, check the age range printed on the box, since children’s formulations contain a lower concentration of the active ingredient.
What Happens if You Take Too Much
Fexofenadine has a relatively wide safety margin compared to older antihistamines. It does not cross into the brain as easily as first-generation antihistamines like diphenhydramine (Benadryl), which means it is far less likely to cause heavy sedation or dangerous central nervous system effects at higher doses. That said, taking more than the recommended amount doesn’t improve symptom relief and can increase the chance of side effects like headache, dizziness, or nausea.
If you accidentally double your dose on a given day, serious harm is unlikely for most adults. But routinely exceeding 180 mg daily offers no benefit and isn’t supported by safety data for over-the-counter use.
Why Allegra Might Not Be Working
If 180 mg feels like it’s not enough, the issue may not be dose. Certain fruit juices, specifically grapefruit, orange, and apple juice, interfere with how your body absorbs fexofenadine. These juices affect transport proteins that move the drug into your bloodstream, meaning less of it actually reaches your system. The FDA recommends not taking Allegra with fruit juices. Swallow it with water instead, and avoid juice for a couple of hours before and after your dose.
Aluminum- and magnesium-based antacids (common ingredients in products like Maalox and Mylanta) also reduce fexofenadine absorption. If you take an antacid regularly, space it at least two hours apart from your Allegra dose so the two don’t compete in your digestive tract.
People Who May Need a Lower Dose
Fexofenadine is primarily cleared through the kidneys. If you have reduced kidney function, the drug can build up in your system faster than your body can eliminate it. In these cases, a lower daily dose or less frequent dosing may be appropriate. This is something a pharmacist or doctor can help calibrate based on how well your kidneys are functioning.
Allegra-D Is a Different Product
Allegra-D combines fexofenadine with pseudoephedrine, a decongestant. The dosing rules are different. The 12-hour version contains 60 mg of fexofenadine and 120 mg of pseudoephedrine, taken twice daily. The 24-hour version contains 180 mg of fexofenadine and 240 mg of pseudoephedrine, taken once daily. The pseudoephedrine component adds its own set of restrictions, including effects on blood pressure and heart rate, so don’t substitute Allegra-D dosing guidelines for regular Allegra or vice versa.