Drug & supplement interaction

Bacillus Subtilis + Darunavir, Cobicistat

Darunavir, Cobicistat brand name: Prezcobix.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 27, 2026
The bottom line No known interaction

We found no known interaction between Bacillus Subtilis and Darunavir, Cobicistat 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. Additionally, although there is no interaction, the label for Darunavir, Cobicistat states a food rule worth keeping to, and the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Bacillus Subtilis and Darunavir, Cobicistat

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 Darunavir, Cobicistat and Bacillus Subtilis 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.

Bacillus Subtilis safety at a glance

Bacillus Subtilis overall Use caution Generally well tolerated in healthy adults, but quality and safety can vary by product and strain.
Pregnancy Use caution There is not enough safety data, so it is best to avoid unless a doctor advises otherwise.
Breastfeeding Use caution Limited safety information exists, so check with your doctor before use.

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

Still wondering about combining Darunavir, Cobicistat and Bacillus Subtilis? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Darunavir, Cobicistat

Interactions in our licensed database are recorded against drug classes, not just single drug names. Darunavir, Cobicistat is filed under 7 classifications — including protease inhibitors (pis), cytochrome p450 1a2 (cyp1a2) inducers, cytochrome p450 2d6 (cyp2d6) inhibitors. Bacillus Subtilis has documented interactions with 1 drug class — the most serious being antibiotic drugs (moderate) — and none of Darunavir, Cobicistat’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

Bacillus Subtilis Does Interact With Other Medications

Bacillus Subtilis has 182 moderate known drug interactions in our database — Darunavir, Cobicistat 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. Darunavir, Cobicistat)
Taking anything else?

Check Another of Your Medications Against Bacillus Subtilis

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

What to actually watch for

No Interaction Found — But Data Suggests Bacillus Subtilis and Darunavir, Cobicistat May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do. One of them is worth acting on rather than waiting out — marked below.

  • Kidney problems Worth acting on Additional detail

    Bacillus Subtilis

    “There are cases of Bacillus subtilis var. natto bacteremia and meningitis in patients with frequent consumption of natto, soybeans fermented with B. subtilis var. natto. A 70-year-old female recovered from bacteremia after this consumption was stopped and she was treated with vancomycin.”

    Bacillus Subtilis · Natural Medicines adverse-effect record, reported in diabetes.

    6 sources cited
    1. 110844. Kato A, Yoshifuji A, Komori K, et al. A case of Bacillus subtilis var. natto bacteremia caused by ingestion of natto during COVID-19 treatment in a maintenance hemodialysis patient with multiple myeloma. J Infect Chemother 2022;28(8):1212-1215. PubMed
    2. 110862. Tokano M, Tarumoto N, Imai K, et al. A case of bacterial meningitis caused by Bacillus subtilis var. natto. Intern Med. 2022. Epub ahead of print.
    3. 110834. Lampropoulos PK, Gkentzi D, Tzifas S, Dimitriou G. Neonatal sepsis due to Bacillus subtilis. Cureus 2021;13(9):e17692. PubMed
    4. 110837. La Jeon Y, Yang JJ, Kim MJ, et al. Combined Bacillus licheniformis and Bacillus subtilis infection in a patient with oesophageal perforation. J Med Microbiol 2012;61(Pt 12):1766-1769. PubMed
    5. 110840. Velasco E, Martins CA, Tabak D, Bouzas LF. "Bacillus subtilis" infection in a patient submitted to a bone marrow transplantation. Rev Paul Med 1992;110(3):116-7.
    6. 110838. Wallet F, Crunelle V, Roussel-Delvallez M, Fruchart A, Saunier P, Courcol RJ. Bacillus subtilis as a cause of cholangitis in polycystic kidney and liver disease. Am J Gastroenterol 1996;91(7):1477-8.

    Darunavir, Cobicistat

    Listed in the ADVERSE REACTIONS section of the FDA label for Darunavir, Cobicistat. Read the label on DailyMed ›

  • Diarrhea Additional detail

    Bacillus Subtilis

    “Orally, diarrhea has been reported rarely.”

    Bacillus Subtilis · Natural Medicines adverse-effect record, reported in diarrhea.

    1 source cited
    1. 110846. Freedman KE, Hill JL, Wei Y, et al. Examining the gastrointestinal and immunomodulatory effects of the novel probiotic Bacillus subtilis DE111. Int J Mol Sci 2021;22(5):2453. PubMed

    Darunavir, Cobicistat

    Listed in the ADVERSE REACTIONS section of the FDA label for Darunavir, Cobicistat. Read the label on DailyMed ›

  • Headache Additional detail

    Bacillus Subtilis

    “Orally, one case of headache was reported in a clinical trial.”

    Bacillus Subtilis · Natural Medicines adverse-effect record, reported in cluster headache.

    1 source cited
    1. 110847. Lefevre M, Racedo SM, Denayrolles M, et al. Safety assessment of Bacillus subtilis CU1 for use as a probiotic in humans. Regul Toxicol Pharmacol 2017;83:54-65. PubMed

    Darunavir, Cobicistat

    Listed in the ADVERSE REACTIONS section of the FDA label for Darunavir, Cobicistat. Read the label on DailyMed ›

Reported for Bacillus Subtilis but not commonly for Darunavir, Cobicistat: a higher chance of infection and itching.

Effects for Darunavir, Cobicistat come from the ADVERSE REACTIONS section of its FDA label; effects for Bacillus Subtilis come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

How to take them

Some Darunavir, Cobicistat Products Have a Food Rule — Bacillus Subtilis Should Not Break It

At least one FDA label for a product containing Darunavir, Cobicistat says to take it with food. If you take Bacillus Subtilis on an empty stomach out of habit, keep them separate — and take Darunavir, Cobicistat with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Darunavir, Cobicistat products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.

2 DOSAGE AND ADMINISTRATION Recommended dosage: Adults and pediatric patients weighing at least 40 kg: One 800 mg/150 mg tablet taken once daily with food.

From the Dosage and Administration section of the FDA label we read for Darunavir, Cobicistat — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›

A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.

Everything else you take

See Every Supplement That Interacts With Darunavir, Cobicistat

This page covers Bacillus Subtilis only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Darunavir, Cobicistat page lists 145 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 102 moderate · 40 minor.

From our pharmacist’s overview on the Darunavir, Cobicistat page

“Prezcobix (darunavir with cobicistat) treats HIV, and it only works if it holds a steady blood level, so this list of 145 supplements deserves real care. Three carry a major rating and matter most: St.”

Reviewed by 2 · Jul 18, 2026

Open the Darunavir, Cobicistat interaction page

One more smart check

Taking Bacillus Subtilis as Part of a Dietary Supplement Product? Check It for Interactions

We hold 786 real supplement products containing Bacillus Subtilis, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Bacillus Subtilis. Even though Bacillus Subtilis itself has no known interaction with Darunavir, Cobicistat, 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 Bacillus Subtilis and Darunavir, Cobicistat 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 Bacillus Subtilis
Top 25%

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

29 days ago today
Medication Darunavir, Cobicistat
Top half

#825 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 Bacillus Subtilis reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 27, 2026. The Bacillus Subtilis and Darunavir, Cobicistat 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 Bacillus Subtilis

What is Bacillus Subtilis?

  • Digestive health and bloating
  • Diarrhea support
  • Immune support
  • Gut microbiome balance

Bacillus subtilis is a spore-forming probiotic bacterium found in soil and some fermented foods, and it is used mainly to support gut health and digestion. Early research is promising for certain digestive and immune uses, but evidence is still limited and not strong enough to make firm claims. Talk to a pharmacist or doctor before using it, especially if you have a weak immune system.

Bacillus subtilis · Bacillaceae · Live bacterial cells and spores (probiotic strains) · Capsules, tablets, powders, and multi-strain probiotic blends

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

Bacillus Subtilis: dosing

There is no official standard dose for Bacillus subtilis. Probiotic amounts are usually measured in CFUs (colony-forming units), and products vary widely.The best approach is to follow the directions on the product label and not exceed the recommended amount.

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

Read the full Bacillus Subtilis monograph & all interactions
Medication

About Darunavir and Cobicistat

What Is Darunavir and Cobicistat Used For?

Brand name: Prezcobix

Prezcobix and Prezcobix Ped are used to treat HIV-1 (human immunodeficiency virus type 1) infection. They are always used together with other antiretroviral (anti-HIV) medicines — never alone. Both products are approved for people who are new to HIV treatment (treatment-naïve) and for those who have taken HIV medicines before (treatment-experienced), as long as certain darunavir resistance mutations are not present.

Prezcobix tablets are approved for adults and pediatric patients weighing at least 40 kg. Prezcobix Ped tablets for oral suspension extend coverage to pediatric patients 3 years of age and older weighing at least 15 kg.

See full Darunavir and Cobicistat drug information
Keep checking

Other Drugs & Bacillus Subtilis

Browse every other medication we’ve checked against Bacillus Subtilis — 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 Bacillus Subtilis page.

No interaction 2,647 drugs checked — show the list

We also checked Bacillus Subtilis 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 Bacillus Subtilis list.

See the full Bacillus Subtilis interactions page
See every supplement checked against Darunavir, Cobicistat, ranked by severity
Evidence & sources

Bacillus Subtilis References

The 10 references that drive our Bacillus Subtilis 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. Lampropoulos PK, Gkentzi D, Tzifas S, Dimitriou G. Neonatal sepsis due to Bacillus subtilis. Cureus 2021;13(9):e17692. PubMed
  3. La Jeon Y, Yang JJ, Kim MJ, et al. Combined Bacillus licheniformis and Bacillus subtilis infection in a patient with oesophageal perforation. J Med Microbiol 2012;61(Pt 12):1766-1769. PubMed
  4. Wallet F, Crunelle V, Roussel-Delvallez M, Fruchart A, Saunier P, Courcol RJ. Bacillus subtilis as a cause of cholangitis in polycystic kidney and liver disease. Am J Gastroenterol 1996;91(7):1477-8.
  5. Velasco E, Martins CA, Tabak D, Bouzas LF. "Bacillus subtilis" infection in a patient submitted to a bone marrow transplantation. Rev Paul Med 1992;110(3):116-7.
  6. Kato A, Yoshifuji A, Komori K, et al. A case of Bacillus subtilis var. natto bacteremia caused by ingestion of natto during COVID-19 treatment in a maintenance hemodialysis patient with multiple myeloma. J Infect Chemother 2022;28(8):1212-1215. PubMed
  7. Freedman KE, Hill JL, Wei Y, et al. Examining the gastrointestinal and immunomodulatory effects of the novel probiotic Bacillus subtilis DE111. Int J Mol Sci 2021;22(5):2453. PubMed
  8. Lefevre M, Racedo SM, Denayrolles M, et al. Safety assessment of Bacillus subtilis CU1 for use as a probiotic in humans. Regul Toxicol Pharmacol 2017;83:54-65. PubMed
  9. Hanifi A, Culpepper T, Mai V, et al. Evaluation of Bacillus subtilis R0179 on gastrointestinal viability and general wellness: a randomised, double-blind, placebo-controlled trial in healthy adults. Benef Microbes 2015;6(1):19-27. PubMed
  10. Tokano M, Tarumoto N, Imai K, et al. A case of bacterial meningitis caused by Bacillus subtilis var. natto. Intern Med. 2022. Epub ahead of print.

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 Bacillus Subtilis and Darunavir, Cobicistat Together: Common Questions

Is it safe to take Bacillus Subtilis with Darunavir, Cobicistat?
We do not list a known interaction between Bacillus Subtilis and Darunavir, Cobicistat. 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.
Do Bacillus Subtilis and Darunavir, Cobicistat have any of the same side effects?
Yes — our sources link each of them separately to 3 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Should I take Bacillus Subtilis and Darunavir, Cobicistat at the same time of day?
At least one FDA label for a product containing Darunavir, Cobicistat says to take it with food. If you take Bacillus Subtilis on an empty stomach out of habit, keep them separate and take Darunavir, Cobicistat with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Darunavir, Cobicistat products can differ — so check the directions on your own box. This is about absorption, not an interaction.
How was the Bacillus Subtilis and Darunavir, Cobicistat combination checked?
Interactions in our licensed database are recorded against drug classes. Darunavir, Cobicistat is filed under 7 classifications, and Bacillus Subtilis has documented interactions with 1 drug class — none of Darunavir, Cobicistat'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 Bacillus Subtilis interact with any other medications?
Yes. Bacillus Subtilis has 182 documented drug interactions in our database — Darunavir, Cobicistat 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 Darunavir, Cobicistat interact with any supplements?
Yes. Darunavir, Cobicistat has documented interactions with 145 supplements in our database — Bacillus Subtilis is not one of them. The Darunavir, Cobicistat 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

Bacillus Subtilis monograph Uses, safety profile, and every drug interaction in one place Darunavir and Cobicistat drug information The full plain-English guide to this medication Darunavir, Cobicistat supplement interactions Every supplement checked against Darunavir, Cobicistat, 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 10 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

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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.