Can Ciprofloxacin INCREASE Appetite?
In our latest question and answer, the pharmacist discusses a reader experiencing an increase in appetite after taking ciprofloxacin.
I’m a 56-year-old woman and have been prescribed ciprofloxacin 500 mg every 12 hours for a urinary tract infection. I've noticed a surprising increase in hunger. Is this a typical side effect?
May 14, 2025- Ciprofloxacin typically causes loss of appetite rather than increased appetite as a side effect.
- Increased appetite has been reported very rarely with ciprofloxacin and is noted in Canadian drug labeling, though this is uncommon.
- If your appetite is improving while taking ciprofloxacin, it may be because your infection is getting better rather than a direct effect of the medication.
Answer
Thanks for reaching out!
Most of the time, ciprofloxacin is associated with a loss of appetite, not an increase. Common sources like Drugs.com and WebMD typically only mention decreased appetite (or “anorexia”) as a possible side effect, and that aligns with what we see in clinical trials and U.S. prescribing information (CIPRO (ciprofloxacin hydrochloride)). Loss of appetite is actually mentioned a few times in the U.S. prescribing information.
However, there are some rare reports of increased hunger or appetite while taking ciprofloxacin. For example, the official Canadian product monograph for ciprofloxacin (CIPRO XL) lists “increased appetite” as a very rare adverse reaction (less than 1% of patients): source.
It’s also been mentioned in other places, such as the ciprofloxacin IV monograph from Baxter. These cases are based on post-marketing data, which means they were reported after the drug was already on the market rather than observed in clinical trials. These reports tend to be less reliable to attribute a side effect to a drug, but are valuable, nonetheless.
So, while appetite loss is not common, it has been observed. It's also possible that if your UTI is improving, you may simply be regaining your appetite as your overall health returns to normal.
Final Words
So, overall, increased appetite isn’t a typical side effect of ciprofloxacin, but it has been documented in rare cases and is noted in Canadian labeling for the drug.
As always, let your doctor or pharmacist know if you experience side effects that are bothersome or persist.
Thanks again for contacting us!
References & sources
Glossary — Terms in This Answer
- Ciprofloxacin
- An antibiotic medication used to treat bacterial infections like urinary tract infections (UTIs).
- Anorexia
- Medical term for loss of appetite or decreased desire to eat.
- Side effect
- An unintended reaction or effect that a medication causes in addition to its intended therapeutic effect.
- Clinical trials
- Research studies conducted on human volunteers to test how well a medication works and document its safety.
- Prescribing information
- Official documentation provided by the drug manufacturer that includes approved uses, dosing, and known side effects.
- Adverse reaction
- A harmful or unwanted effect caused by taking a medication.
- Post-marketing data
- Safety and effectiveness information collected after a drug has been approved and made available to the general public.
- UTI
- Short for urinary tract infection, a bacterial infection affecting the urinary system.
Dr. Brian Staiger, PharmD
Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified
Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...
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