What Is Alinia? Uses, Dosage, and What You Need to Know in 2026

If you've been prescribed Alinia and want to understand exactly what it is, what it does, and how to take it correctly, you're in the right place. This guide covers the essentials of Alinia (nitazoxanide) in plain language.

What Is Alinia?

Alinia is the brand name for nitazoxanide, a prescription antiprotozoal medication. It was FDA-approved in 2004 and is manufactured by Romark Laboratories. Alinia works by interfering with the energy metabolism of certain parasites, effectively killing them. It is not an antibiotic and will not treat bacterial or viral infections — it's specifically designed to fight protozoal (parasitic) organisms.

A generic version (nitazoxanide) was approved in 2020 and is therapeutically equivalent to brand Alinia. Both brand and generic are available in two forms: 500 mg film-coated tablets and a 100 mg/5 mL oral suspension.

What Is Alinia Used For?

Alinia is FDA-approved to treat diarrhea caused by two specific intestinal parasites:

Giardia lamblia — the cause of giardiasis, a common intestinal illness spread through contaminated water or food. Symptoms include watery or greasy diarrhea, stomach cramps, bloating, gas, nausea, and fatigue. Giardia is common in hikers, travelers, and children in daycare.

Cryptosporidium parvum — the cause of cryptosporidiosis, a diarrheal illness also spread through contaminated water. It can be severe in immunocompromised patients. Note: Alinia has NOT been shown effective for cryptosporidiosis in HIV-positive or immunodeficient patients.

Beyond these FDA-approved uses, Alinia is also used off-label for other parasitic infections including amebiasis (Entamoeba histolytica), cyclosporiasis, Blastocystis species infections, and certain intestinal helminth infections.

Who Can Take Alinia?

Alinia tablets (500 mg): Adults and adolescents 12 years and older

Alinia oral suspension (100 mg/5 mL): Children 1 year and older (tablets contain too much drug for children under 12)

NOT for: Infants under 1 year (safety not established); HIV-positive or immunodeficient patients with cryptosporidiosis (not shown effective)

Alinia Dosage Instructions

The standard course for treating giardiasis and cryptosporidiosis is just 3 days. Here are the doses by age:

Adults and adolescents (12+): 500 mg tablet twice daily for 3 days (total 6 tablets), always with food

Children ages 4–11: 200 mg (10 mL suspension) twice daily for 3 days, with food

Children ages 1–3: 100 mg (5 mL suspension) twice daily for 3 days, with food

Critical rule: Always take Alinia with food. Food nearly doubles the amount of medication absorbed by your body. Taking it on an empty stomach makes the treatment less effective and increases stomach side effects.

How Long Does Alinia Take to Work?

Most patients begin to notice improvement in diarrhea symptoms within the 3-day treatment course, with full resolution typically occurring within 4–7 days after completing treatment. In clinical trials, 80–85% of patients achieved clinical resolution (no symptoms or minimal soft stools) within a few days after finishing the 3-day course.

Important: Don't stop early even if you feel better. Complete all 6 tablets (or all suspension doses). Stopping early can lead to treatment failure and harder-to-treat re-infection.

Important Things to Know Before Taking Alinia

The oral suspension expires after 7 days. The reconstituted suspension should be stored at room temperature and discarded after 7 days — even if some remains.

Your urine may turn yellow. This is a known, harmless side effect (chromaturia) that resolves after treatment ends.

The parasite can still be in your stool after treatment. Even after you feel better, Giardia cysts can be present in stool for up to a week. Wash your hands carefully after using the bathroom.

No alcohol restriction. Unlike metronidazole, Alinia does not interact with alcohol. However, heavy alcohol use can impair immune function and slow recovery.

Alinia is NOT a controlled substance. Any prescriber can write it and it can be prescribed via telehealth.

Where to Fill Your Alinia Prescription

Alinia isn't always on pharmacy shelves due to low prescription volume. Call ahead and ask for 'nitazoxanide' (the generic name) or use medfinder to have pharmacies searched for you. See our full guide on how to find Alinia in stock near you.