Drug & supplement interaction

Lactobacillus Crispatus + Interferon Alfa-2b

Interferon Alfa-2b brand names: Rebetron, Intron A, Viraferon.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Lactobacillus Crispatus and Interferon Alfa-2b in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.

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Interaction report

Lactobacillus Crispatus and Interferon Alfa-2b

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Interferon Alfa-2b and Lactobacillus Crispatus in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Lactobacillus Crispatus safety at a glance

Lactobacillus Cris... overall Use caution Generally considered safe for healthy people, but quality and evidence vary by product.
Pregnancy Use caution Limited safety data; use only under the guidance of your doctor.
Breastfeeding Use caution Not well studied during breastfeeding; check with your doctor first.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Interferon Alfa-2b and Lactobacillus Crispatus? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Interferon Alfa-2b

Interactions in our licensed database are recorded against drug classes, not just single drug names. Interferon Alfa-2b is filed under 2 classifications — photosensitizing drugs, hepatotoxic drugs. Lactobacillus Crispatus has documented interactions with 1 drug class — the most serious being antibiotic drugs (moderate) — and none of Interferon Alfa-2b’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Lactobacillus Crispatus Does Interact With Other Medications

Lactobacillus Crispatus has 182 moderate known drug interactions in our database — Interferon Alfa-2b isn’t one of them. If you take anything else, check it against the full list below.

Moderate 182 No known interaction 2,648 (incl. Interferon Alfa-2b)
Taking anything else?

Check Another of Your Medications Against Lactobacillus Crispatus

Covers the 2,830 medications we’ve checked against Lactobacillus Crispatus. Pick one to open its full report.

What to actually watch for

What Lactobacillus Crispatus Itself Has Been Linked To

This is not an interaction — nothing below involves Interferon Alfa-2b. It is the side-effect record for Lactobacillus Crispatus on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Lactobacillus Crispatus, this list is the first place to look. One entry is worth acting on rather than waiting out — marked below.

  • A higher chance of infection Worth acting on Additional detail

    “Orally, taking Lactobacillus crispatus has rarely caused a swollen tongue and epiglottis.

    Since Lactobacillus crispatus preparations contain live and active microorganisms, there is some concern that they might cause pathogenic infection in some patients.”

    Lactobacillus Crispatus · Natural Medicines adverse-effect record, reported in sepsis.

    6 sources cited
    1. 110945. DE Leo V, Lazzeri E, Governini L, et al. Vaginal colonization of women after oral administration of Lactobacillus crispatus strain NTCVAG04 from the human microbiota. Minerva Obstet Gynecol 2022. PubMed
    2. 107543. Rossi F, Amadoro C, Gasperi M, Colavita G. Lactobacilli infection case reports in the last three years and safety implications. Nutrients. 2022;14(6):1178. PubMed
    3. 110917. Ranchal P, Gupta R, Goldberg R, A Lobo S, Pascual A, El Khoury MY. Penicillin-sensitive Lactobacillus jensenii bacteremia. Am J Ther 2021;28(2):e250-e252. PubMed
    4. 110918. Grazioli-Gauthier L, Rigamonti E, Leo LA, Martinetti Lucchini G, Lo Priore E, Bernasconi E. Lactobacillus jensenii mitral valve endocarditis: Case report, literature review and new perspectives. IDCases 2022;27:e01401. PubMed
    5. 110920. Toprak NU, Bozan T, Yilmaz S, Buyukbayrak EE, Tigen ET. Polymicrobial bacteremia due to Lactobacillus jensenii and Veillonella montpellierensis in a pregnant patient; case report and review of literature. Anaerobe 2022;75:102576. PubMed
    6. 110921. Chazan B, Raz R, Shental Y, Sprecher H, Colodner R. Bacteremia and pyelonephritis caused by Lactobacillus jensenii in a patient with urolithiasis. Isr Med Assoc J 2008;10(2):164-5.
  • Bloating or gas / Nausea Additional detail

    “Orally, taking Lactobacillus crispatus has rarely caused nausea, gas, and flatulence in clinical research.”

    Lactobacillus Crispatus · Natural Medicines adverse-effect record, reported in flatulence.

    2 sources cited
    1. 110942. DI Pierro F, Criscuolo AA, Dei Giudici A, et al. Oral administration of Lactobacillus crispatus M247 to papillomavirus-infected women: results of a preliminary, uncontrolled, open trial. Minerva Obstet Gynecol 2021;73(5):621-631. PubMed
    2. 110946. Dellino M, Cascardi E, Laganà AS, et al. Lactobacillus crispatus M247 oral administration: Is it really an effective strategy in the management of papillomavirus-infected women?. Infect Agent Cancer 2022;17(1):53. PubMed

Everything above comes from the Natural Medicines adverse-effect record for Lactobacillus Crispatus — expand a row for the licensed statement it rests on. We haven’t matched Interferon Alfa-2b to its FDA label in our system yet, so we can’t compare its own side-effect list here — the leaflet that comes with your prescription is the authoritative list for Interferon Alfa-2b.

Everything else you take

See Every Supplement That Interacts With Interferon Alfa-2b

This page covers Lactobacillus Crispatus only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Interferon Alfa-2b page lists 57 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Beer (major), Siberian Cocklebur (major), Wine (major), Alfalfa (moderate) and Angelica Archangelica (moderate).

By severity: 3 major · 53 moderate · 1 minor.

From our pharmacist’s overview on the Interferon Alfa-2b page

“People taking interferon alfa-2b (Intron A, Rebetron) are usually treating hepatitis or a cancer, so the liver may already be under strain, and that is exactly where most of this list points. Of the 57 supplements on file, 38 can add to liver stress, and all three major-rated interactions sit in that group: Siberian cocklebur, which ha…”

Reviewed by 2 · Jul 18, 2026

Open the Interferon Alfa-2b interaction page

One more smart check

Taking Lactobacillus Crispatus as Part of a Dietary Supplement Product? Check It for Interactions

We hold 48 real supplement products containing Lactobacillus Crispatus, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Lactobacillus Crispatus. Even though Lactobacillus Crispatus itself has no known interaction with Interferon Alfa-2b, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Lactobacillus Crispatus and Interferon Alfa-2b Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Lactobacillus Crispatus
Top half

#547 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Interferon Alfa-2b
Steady interest

#1,580 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Lactobacillus Crispatus reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Lactobacillus Crispatus and Interferon Alfa-2b records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Lactobacillus Crispatus

What is Lactobacillus Crispatus?

  • Vaginal health support
  • Preventing recurrent bacterial vaginosis
  • Reducing recurrent urinary tract infections
  • Yeast infection support
  • General microbiome balance

Lactobacillus crispatus is a 'good' bacterium that naturally dominates a healthy vaginal microbiome and is sold as a probiotic, mainly for vaginal and urinary health. Early research is promising for preventing recurrent bacterial vaginosis and urinary tract infections, but evidence is still limited and product quality varies. Talk with your pharmacist or doctor before using it, especially if you are pregnant or have a weakened immune system.

Lactobacillus crispatus · Lactobacillaceae · Live bacterial cells (probiotic strain) · Oral capsules, vaginal capsules or suppositories, powders, some yogurts and fermented foods

An interaction check asks whether these two react with each other — it does not ask whether Lactobacillus Crispatus is a good idea for someone in your situation. Here is what our Lactobacillus Crispatus record says about it on its own.

Lactobacillus Crispatus: dosing

There is no single standardized dose of Lactobacillus crispatus. Probiotic doses are usually measured in colony-forming units (CFU), and the right amount can vary by product and by why you are using it.The best approach is to follow the directions on the product label for the specific oral or vaginal product you have chosen.

From our Lactobacillus Crispatus monograph — the full record covers uses, side effects and every documented interaction.

Read the full Lactobacillus Crispatus monograph & all interactions
Medication

About Interferon Alfa-2b Injection

What Is Interferon Alfa-2b Injection Used For?

Brand names: Rebetron, Intron A, Viraferon

  • Interferon alfa-2b injection is used to treat a number of conditions.

  • Interferon alfa-2b injection is used

    • alone or in combination with ribavirin (Copegus, Rebetol, Ribasphere) to treat chronic (long-term) hepatitis C infection (swelling of the liver caused by a virus) in people who show signs of liver damage,

    • to treat chronic hepatitis B infection (swelling of the liver caused by a virus) in people who show signs of liver damage,

    • to treat hairy cell leukemia (a white blood cell cancer),

    • to treat genital warts,

    • to treat Kaposi's sarcoma (a type of cancer that causes abnormal tissue to grow on different parts of the body) related to acquired immunodeficiency syndrome (AIDS),

    • to treat malignant melanoma (a cancer that begins in certain skin cells) in certain people who have had surgery to remove the cancer,

    • along with another medication to treat follicular non-Hodgkin's lymphoma (NHL; a slow-growing blood cancer).

  • Interferon alfa-2b is in a class of medications called immunomodulators. Interferon alfa-2b works to treat hepatitis C virus (HCV) and hepatitis B virus (HBV) by decreasing the amount virus in the body. Interferon alfa-2b may not cure hepatitis B or hepatitis C or prevent you from developing complications from these infections such as cirrhosis (scarring) of the liver, liver failure, or liver cancer. It also may not prevent the spread of hepatitis B or C to other people. It is not known exactly how interferon alfa-2b works to treat cancer or genital warts.

See full Interferon Alfa-2b Injection drug information
Keep checking

Other Drugs & Lactobacillus Crispatus

Browse every other medication we’ve checked against Lactobacillus Crispatus — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
182Moderate
0Minor
2,647No known interaction
182 Moderate 2,647 No interaction
Moderate

182 interactions

Showing 60 of 182 moderate interactions — see all 182 on the Lactobacillus Crispatus page.

No interaction 2,647 drugs checked — show the list

We also checked Lactobacillus Crispatus against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,647 medications checked with no known interaction — see the full Lactobacillus Crispatus list.

See the full Lactobacillus Crispatus interactions page
See every supplement checked against Interferon Alfa-2b, ranked by severity
Evidence & sources

Lactobacillus Crispatus References

The 9 references that drive our Lactobacillus Crispatus monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Pierce A. The American Pharmaceutical Association Practical Guide to Natural Medicines. New York: The Stonesong Press, 1999:19.
  2. Rossi F, Amadoro C, Gasperi M, Colavita G. Lactobacilli infection case reports in the last three years and safety implications. Nutrients. 2022;14(6):1178. PubMed
  3. Ranchal P, Gupta R, Goldberg R, A Lobo S, Pascual A, El Khoury MY. Penicillin-sensitive Lactobacillus jensenii bacteremia. Am J Ther 2021;28(2):e250-e252. PubMed
  4. Grazioli-Gauthier L, Rigamonti E, Leo LA, Martinetti Lucchini G, Lo Priore E, Bernasconi E. Lactobacillus jensenii mitral valve endocarditis: Case report, literature review and new perspectives. IDCases 2022;27:e01401. PubMed
  5. Toprak NU, Bozan T, Yilmaz S, Buyukbayrak EE, Tigen ET. Polymicrobial bacteremia due to Lactobacillus jensenii and Veillonella montpellierensis in a pregnant patient; case report and review of literature. Anaerobe 2022;75:102576. PubMed
  6. Chazan B, Raz R, Shental Y, Sprecher H, Colodner R. Bacteremia and pyelonephritis caused by Lactobacillus jensenii in a patient with urolithiasis. Isr Med Assoc J 2008;10(2):164-5.
  7. DI Pierro F, Criscuolo AA, Dei Giudici A, et al. Oral administration of Lactobacillus crispatus M247 to papillomavirus-infected women: results of a preliminary, uncontrolled, open trial. Minerva Obstet Gynecol 2021;73(5):621-631. PubMed
  8. DE Leo V, Lazzeri E, Governini L, et al. Vaginal colonization of women after oral administration of Lactobacillus crispatus strain NTCVAG04 from the human microbiota. Minerva Obstet Gynecol 2022. PubMed
  9. Dellino M, Cascardi E, Laganà AS, et al. Lactobacillus crispatus M247 oral administration: Is it really an effective strategy in the management of papillomavirus-infected women?. Infect Agent Cancer 2022;17(1):53. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Lactobacillus Crispatus and Interferon Alfa-2b Together: Common Questions

Is it safe to take Lactobacillus Crispatus with Interferon Alfa-2b?
We do not list a known interaction between Lactobacillus Crispatus and Interferon Alfa-2b. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
How was the Lactobacillus Crispatus and Interferon Alfa-2b combination checked?
Interactions in our licensed database are recorded against drug classes. Interferon Alfa-2b is filed under 2 classifications, and Lactobacillus Crispatus has documented interactions with 1 drug class — none of Interferon Alfa-2b's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Lactobacillus Crispatus interact with any other medications?
Yes. Lactobacillus Crispatus has 182 documented drug interactions in our database — Interferon Alfa-2b is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Interferon Alfa-2b interact with any supplements?
Yes. Interferon Alfa-2b has documented interactions with 57 supplements in our database — Lactobacillus Crispatus is not one of them. The Interferon Alfa-2b interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

Keep Exploring

Lactobacillus Crispatus monograph Uses, safety profile, and every drug interaction in one place Interferon Alfa-2b Injection drug information The full plain-English guide to this medication Interferon Alfa-2b supplement interactions Every supplement checked against Interferon Alfa-2b, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 9 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Interferon Alfa-2b and Lactobacillus Crispatus?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.