What is the best antibiotic for a sinus infection?

There's rarely one "best" — the first-line options per US guidelines are amoxicillin (with or without clavulanate), amoxicillin-clavulanate. The right choice depends on the specific infection, local resistance, and any allergies, and it's decided by a clinician. Antibiotics are prescription-only.

Can I get antibiotics for a sinus infection without a prescription?

No. Antibiotics are prescription-only in the US for good reason — the wrong drug or an unnecessary course drives resistance and side effects. Never use leftover antibiotics or someone else's. See a clinician or a telehealth provider.

What if I'm allergic to penicillin?

Guideline alternatives include doxycycline; respiratory fluoroquinolone (levofloxacin). Tell your clinician the exact reaction you had — most reported penicillin "allergies" aren't true allergies.

Best antibiotics for a sinus infection

Most sinus infections are viral and get better on their own — antibiotics only help the minority that are bacterial (typically symptoms lasting 10+ days without improvement, or that worsen after initial improvement). Watchful waiting is a reasonable first step.

By the pharmaranks editorial teamReviewed against US clinical guidelines (CDC, IDSA, AAP/AAFP, ADA) sourcesHow we research

First-line options

What guidelines recommend to try first. Tap one we rate for its independent monograph.

Amoxicillin (with or without clavulanate)
First-line per CDC/AAFP when a bacterial sinus infection is treated; amoxicillin-clavulanate is preferred when broader coverage is wanted.
Amoxicillin-clavulanate
The IDSA-preferred agent for acute bacterial rhinosinusitis.

If you’re penicillin-allergic, or first-line fails

Doxycycline
An alternative for penicillin allergy.
Respiratory fluoroquinolone (levofloxacin)
An alternative for penicillin allergy (moxifloxacin is also used).

When antibiotics aren’t needed

Azithromycin and other macrolides are NOT recommended for sinus infections because of high pneumococcal resistance (~40%). And most sinusitis needs no antibiotic at all.

Full overview: understanding sinus infection (sinusitis)& how it’s treated →

FAQ

What is the best antibiotic for a sinus infection?: There's rarely one "best" — the first-line options per US guidelines are amoxicillin (with or without clavulanate), amoxicillin-clavulanate. The right choice depends on the specific infection, local resistance, and any allergies, and it's decided by a clinician. Antibiotics are prescription-only.
Can I get antibiotics for a sinus infection without a prescription?: No. Antibiotics are prescription-only in the US for good reason — the wrong drug or an unnecessary course drives resistance and side effects. Never use leftover antibiotics or someone else's. See a clinician or a telehealth provider.
What if I'm allergic to penicillin?: Guideline alternatives include doxycycline; respiratory fluoroquinolone (levofloxacin). Tell your clinician the exact reaction you had — most reported penicillin "allergies" aren't true allergies.

Antibiotics for other infections

a UTI strep throat an ear infection a tooth infection pink eye bronchitis

Source

CDC — Antibiotic Prescribing and Use: Outpatient Clinical Care for Adults ↗

General reference, not medical advice. Antibiotics are prescription-only; the right one depends on the specific infection, local resistance, your allergies, and your clinician’s judgment. Don’t self-treat, and never use leftover antibiotics or someone else’s — that drives resistance and can be dangerous. See a licensed clinician.