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How long does it take for Biaxin to work?

Medically reviewed by Sally Chao, MD. Last updated on Oct 1, 2021.

Official answer


In most cases, it should only take a few days for Biaxin (clarithromycin) to reduce the symptoms of your infection and make you feel better. For some infections, it may take longer for signs and symptoms to go away. For example, clarithromycin can take around 7 days to have a noticeable effect on skin infections such as cellulitis.

Biaxin may also take longer than a few days to resolve symptoms of a stomach infection caused by the bacteria Helicobacter pylori (H. pylori). Even if the drug has eliminated the H. pylori bacteria, symptoms can persist if the infection caused an ulcer to form. In this case, your doctor may prescribe an acid-reducing medication as well.

Clarithromycin is typically prescribed as a 7- to 14-day treatment, meaning that even if your symptoms have resolved after a few days, you will still need to continue taking the medication until you’ve completed the entire course of treatment. Stopping the medication early can result in bacteria being left behind, potentially leading to antibiotic resistance and increasing the risk that the infection returns.

The half-life of clarithromycin can range from 3 to 4 hours for a lower dose (250 mg) to 5 to 7 hours for a higher dose (500 mg). This means that 250 mg of clarithromycin will be completely eliminated from the body 16 to 22 hours after taking it, while 500 mg of clarithromycin will be eliminated about a day and a half following the last dose.

  1. National Health Service (NHS). Clarithromycin. December 6, 2018. Available at: [Accessed September 27, 2021].
  2. U.S. National Library of Medicine MedlinePlus. Clarithromycin. June 15, 2020. Available at: [Accessed September 27, 2021].
  3. U.S. Food and Drug Administration (FDA). BIAXIN® Filmtab® (clarithromycin tablets, USP) BIAXIN® XL Filmtab® (clarithromycin extended-release tablets) BIAXIN® Granules (clarithromycin for oral suspension, USP). June 2012. Available at:,050698s029,050775s018lbl.pdf. [Accessed September 27, 2021].

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