Adults and children 12 and older can take one 180 mg Allegra tablet once a day, or one 60 mg tablet twice a day. Both options deliver the same total of 180 mg in 24 hours, which is the standard recommended maximum. Taking more than that in a single day is not advised.
Standard Adult Dose
Allegra comes in two common tablet strengths, and the one you have determines how many you take. If you have the 180 mg tablets, take one per day. If you have the 60 mg tablets, take one every 12 hours, for a total of two per day. These two regimens are equivalent, and the 180 mg once-daily option is simply the more convenient version of the same total dose.
The drug starts working within about an hour, reaches peak effectiveness at two to three hours, and continues providing relief for a full 12 hours per dose. That timeline is why the 60 mg version is labeled for twice-daily use: each dose covers roughly half the day.
Children’s Dosing
Children ages 2 through 11 use a lower dose. The liquid suspension is dosed at 5 mL (one teaspoon) every 12 hours, with a maximum of 10 mL in 24 hours. Chewable tablets for this age group contain 30 mg each, taken twice daily. Children under 2 should not take over-the-counter Allegra without specific guidance from a pediatrician.
Why You Shouldn’t Double Up
If your allergies are still bothering you after taking the recommended dose, taking extra Allegra is unlikely to help. The drug’s behavior in the body is predictable and proportional up to about 240 mg per day, but going beyond the 180 mg recommendation doesn’t produce meaningfully better symptom control. If 180 mg isn’t enough, the issue is more likely that Allegra isn’t the right antihistamine for your symptoms, or that you need a different type of allergy treatment altogether, like a nasal steroid spray.
If you accidentally take an extra dose, serious harm is unlikely. Allegra has a wide safety margin compared to older antihistamines, and it doesn’t cause significant drowsiness or heart rhythm problems at moderately elevated doses. Still, don’t make a habit of exceeding the label instructions.
Kidney Function Changes the Dose
People with reduced kidney function should start at a lower dose because the body clears the drug more slowly. The recommended starting point is 60 mg once daily rather than 180 mg. The same applies to children with kidney issues: 30 mg once daily for ages 2 to 12, and 60 mg once daily for those 12 and older. If you know you have kidney disease, check with your pharmacist before following the standard label.
Fruit Juice Reduces How Well It Works
One of the more surprising things about Allegra is that common fruit juices can dramatically reduce how much of the drug your body absorbs. Grapefruit, orange, and apple juice all interfere with the transport mechanism that moves the drug from your gut into your bloodstream. The FDA label specifically says not to take Allegra with fruit juices. Water is the best choice when swallowing your dose.
Antacids containing aluminum or magnesium cause a similar problem, cutting absorption by roughly 40%. If you take an antacid, wait at least two hours before taking your Allegra so the two don’t compete in your digestive tract.
Older Adults
There is no separate dose recommendation for adults over 65 with normal kidney function. The standard 180 mg once daily (or 60 mg twice daily) applies. Because kidney function naturally declines with age, however, older adults are more likely to fall into the reduced-kidney-function category without realizing it. If you’re over 65 and haven’t had your kidney function checked recently, the lower starting dose of 60 mg once daily is a reasonable precaution.
If It’s Not Working
Allegra is a second-generation antihistamine, meaning it targets histamine without crossing into the brain the way older allergy medications do. That’s why it rarely causes drowsiness, but it also means it only addresses histamine-driven symptoms: sneezing, itchy or watery eyes, and a runny nose. It does very little for nasal congestion. If stuffiness is your main complaint, Allegra alone won’t solve the problem. A nasal corticosteroid spray or an Allegra-D formulation (which adds a decongestant) covers that gap.
Some people also find that one antihistamine works better for them than another, even within the same drug class. If you’ve been taking the full 180 mg daily for several days with minimal relief, switching to a different antihistamine is a more effective strategy than increasing the Allegra dose beyond what’s recommended.