Availability varies by country and changes over time, which is exactly the kind of fact that goes stale on a website. Ask a pharmacist rather than trusting any page, including this one, on current availability where you live.

Is the cash price the same everywhere?

No. Cash prices vary between pharmacies and between countries, and discount programmes change what is actually paid at the counter. That is why the figure on this page is a dated range rather than a single number. A quote you were given in one place is worth checking against another before you treat it as the price.

What are the side effects?

This is prescription-only and we do not reproduce prescribing information, because a partial version of it read off a website is worse than none. The prescriber and the pharmacist both hold the full document and both are expected to go through it with you. That is a better source than this page, and asking for it is an ordinary thing to do.

Rifaximin

By BeatSIBO editorial team · Updated August 5, 2026

The reason this comes up as often as it does is mostly economic rather than clinical.

Insurance coverage
Why it moves the number:
Decides whether you see list price at all
Can we tell you yours?:
No
Course length
Why it moves the number:
Priced per tablet, so duration scales the total
Can we tell you yours?:
No. That is a clinical decision
Pharmacy and location
Why it moves the number:
Cash prices vary between pharmacies in the same city
Can we tell you yours?:
No
Repeat rounds
Why it moves the number:
Non-response and recurrence are both commonly reported
Can we tell you yours?:
No. Budget for the possibility

What decides the price you are quoted
Variable	Why it moves the number	Can we tell you yours?
Insurance coverage	Decides whether you see list price at all	No
Course length	Priced per tablet, so duration scales the total	No. That is a clinical decision
Pharmacy and location	Cash prices vary between pharmacies in the same city	No
Repeat rounds	Non-response and recurrence are both commonly reported	No. Budget for the possibility

We publish the verified cash list price and the date we checked it, on the cost page. Everything in this table is a reason the number you are quoted may differ from it, and none of it is something a website can look up for you.

What rifaximin is

The short answer

A prescription antibiotic that stays largely inside the gut rather than being absorbed into the bloodstream. That property is why it is used for gut conditions and why its side effect profile differs from antibiotics that circulate systemically. It is prescription-only, which means this page cannot and will not tell you how to use it.

That pattern is worth noticing: the intervention people research hardest is frequently the one they cannot afford or cannot get.

The cost, which is the actual story

The short answer

Cash prices commonly quoted in the United States for a two week course run in the region of 2,200 to 2,940 dollars without insurance coverage. That number explains most of the search behaviour in this entire niche. People are not looking for alternatives because the alternatives are better documented. They are looking because of that price.

Any page recommending herbal alternatives that does not mention this is hiding the reason its readers arrived. The full cost of a course, end to end, is broken down separately. We think the honest framing is that a comparison between a well-studied expensive option and a poorly studied cheap one is not really a clinical comparison at all.

What the evidence actually supports

Pimentel M et al., American Journal of Gastroenterology 2020 Clinical guideline

Read that carefully. The guideline that covers this condition rates five of its six recommendations as resting on very low quality evidence, and every one of the six is conditional. That is the state of the best-documented option here.

Kashyap P et al., Neurogastroenterology & Motility 2024 Peer-reviewed studyWe have not yet confirmed a direct link to this document, so we are not giving you one. The citation above is enough to find it, and we would rather say this than send you to a journal front page.

And there is a live argument that the test used to select people for it should not be used at all.

What is not settled here

Non-response is one of the largest recurring themes in patient discussion, and there is no reliable way to predict in advance who will respond. A positive breath test is information about gas production, not a prediction about a drug. Anyone telling you otherwise is going beyond what the evidence supports.

If it did not work

Non-response is common enough to be an ordinary outcome rather than a sign that something went wrong, and there is no way to predict it in advance. What happens next is a prescribing decision, so it belongs with a clinician who can see your history rather than with a website.

Common questions

Is there a generic?: Availability varies by country and changes over time, which is exactly the kind of fact that goes stale on a website. Ask a pharmacist rather than trusting any page, including this one, on current availability where you live.
Is the cash price the same everywhere?: No. Cash prices vary between pharmacies and between countries, and discount programmes change what is actually paid at the counter. That is why the figure on this page is a dated range rather than a single number. A quote you were given in one place is worth checking against another before you treat it as the price.
What are the side effects?: This is prescription-only and we do not reproduce prescribing information, because a partial version of it read off a website is worse than none. The prescriber and the pharmacist both hold the full document and both are expected to go through it with you. That is a better source than this page, and asking for it is an ordinary thing to do.