How long does allergy pill last in your body?

The duration of action of allergy pills (also known as antihistamines) in the body can vary depending on the specific medication and individual factors. Here are the approximate durations of action for some common antihistamines:

1. Loratadine (Claritin): Loratadine has a long duration of action, lasting up to 24 hours.

2. Cetirizine (Zyrtec): Cetirizine also has a long duration of action, similar to loratadine, and can last up to 24 hours.

3. Fexofenadine (Allegra): Fexofenadine has a moderate duration of action, lasting around 12 hours.

4. Desloratadine (Clarinex): Desloratadine has a long duration of action, similar to loratadine and cetirizine, lasting up to 24 hours.

5. Levocetirizine (Xyzal): Levocetirizine, an active metabolite of cetirizine, also has a long duration of action, lasting up to 24 hours.

6. Diphenhydramine (Benadryl): Diphenhydramine is a first-generation antihistamine with a shorter duration of action, typically lasting around 4-6 hours.

It's important to note that the duration of action provided is an average estimate and can vary from person to person. Factors such as individual metabolism, liver function, kidney function, age, and other medications being taken can influence the duration of action of allergy pills. If you have specific concerns about the duration of action of an allergy pill or how it affects you, it's best to consult with a healthcare professional.