Drug & supplement interaction

Papain + Nirmatrelvir, Ritonavir

Nirmatrelvir, Ritonavir brand name: Paxlovid.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Papain and Nirmatrelvir, Ritonavir 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 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

Papain and Nirmatrelvir, Ritonavir

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 Nirmatrelvir, Ritonavir and Papain 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.

Papain safety at a glance

Papain overall Use caution Generally tolerated as a food, but supplements may irritate the digestive tract and cause allergic reactions.
Pregnancy Possibly Unsafe When used orally. There is some concern that crude papain is teratogenic and embryotoxic. Read the full pregnancy detail
Breastfeeding Use caution Not enough reliable safety information exists, so it is best to avoid supplemental papain while breastfeeding.

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Nirmatrelvir, Ritonavir and Papain? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Nirmatrelvir, Ritonavir

Interactions in our licensed database are recorded against drug classes, not just single drug names. Nirmatrelvir, Ritonavir is filed under 7 classifications — including cytochrome p450 3a4 (cyp3a4) inhibitors, hepatotoxic drugs, cytochrome p450 3a4 (cyp3a4) substrates. Papain has documented interactions with 1 drug class — the most serious being warfarin (coumadin) (moderate) — and none of Nirmatrelvir, Ritonavir’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

Papain Does Interact With Other Medications

Papain has 2 moderate known drug interactions in our database — Nirmatrelvir, Ritonavir isn’t one of them. If you take anything else, check it against the full list below.

Moderate 2 No known interaction 2,828 (incl. Nirmatrelvir, Ritonavir)
Taking anything else?

Check Another of Your Medications Against Papain

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

What to actually watch for

No Interaction Found — But Data Suggests Papain and Nirmatrelvir, Ritonavir 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.

  • An allergic reaction Worth acting on Additional detail

    Papain

    “Occupational exposure to airborne papain dust may cause respiratory allergic reactions. Symptoms include rhinitis, sneezing, conjunctivitis, dyspnea, wheezing, cough, and asthma. In most cases, papain is confirmed as the causative agent by skin prick tests, radioallergosorbent tests (RAST), or detection of papain-specific immunoglobulin E (IgE) and IgG.”

    Papain · Natural Medicines adverse-effect record, reported in asthma.

    5 sources cited
    1. 95532. Tymoszuk D, Wiszniewska M, Walusiak-Skorupa J. Papain-induced occupational rhinoconjunctivitis and asthma - A case report. Med Pr 2016;67(1):109-12. PubMed
    2. 95533. Soto-Mera MT, López-Rico MR, Filgueira JF, et al. Occupational allergy to papain. Allergy 2000;55(10):983-4. PubMed
    3. 95534. Tarlo SM, Shaikh W, Bell B, et al. Papain-induced allergic reactions. Clin Allergy 1978;8(3):207-15. PubMed
    4. 95535. Baur X, König G, Bencze K, Fruhmann G. Clinical symptoms and results of skin test, RAST and bronchial provocation test in thirty-three papain workers: Evidence for strong immunogenic potency and clinically relevant proteolytic e?ects of airborne papain. C
    5. 95536. Novey HS, Keenan WJ, Fairshter RD, Wells ID, Wilson AF, Culver BD. Pulmonary disease in workers exposed to papain: clinico-physiological and immunological studies. Clin Allergy 1980;10(6):721-31. PubMed

    Nirmatrelvir, Ritonavir

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

  • Diarrhea Additional detail

    Papain

    “Orally, papain may cause allergic reactions, including itchy watery eyes, runny nose, sneezing, abdominal cramps, sweating, and diarrhea, in individuals sensitive to papain (6,967). Occupational exposure to airborne papain dust may also cause respiratory allergic reactions.”

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

    6 sources cited
    1. 6. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
    2. 967. Mansfield LE, Ting S, Haverly RW, Yoo TJ. The incidence and clinical implications of hypersensitivity to papain in an allergic population, confirmed by blinded oral challenge. Ann Allergy 1985;55:541-3.
    3. 95532. Tymoszuk D, Wiszniewska M, Walusiak-Skorupa J. Papain-induced occupational rhinoconjunctivitis and asthma - A case report. Med Pr 2016;67(1):109-12. PubMed
    4. 95533. Soto-Mera MT, López-Rico MR, Filgueira JF, et al. Occupational allergy to papain. Allergy 2000;55(10):983-4. PubMed
    5. 95534. Tarlo SM, Shaikh W, Bell B, et al. Papain-induced allergic reactions. Clin Allergy 1978;8(3):207-15. PubMed
    6. 95535. Baur X, König G, Bencze K, Fruhmann G. Clinical symptoms and results of skin test, RAST and bronchial provocation test in thirty-three papain workers: Evidence for strong immunogenic potency and clinically relevant proteolytic e?ects of airborne papain. C

    “Orally, papain has been associated with diarrhea. In a randomized controlled trial assessing the effects of papain, trypsin, and chymotrypsin on adverse effects from radiotherapy, moderate to severe diarrhea was more frequent in the enzyme-treated group than the placebo group. However, it is unclear if this adverse effect is due to papain, other enzymes, or the combination.”

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

    3 sources cited
    1. 67834. Martin, T., Uhder, K., Kurek, R., Roeddiger, S., Schneider, L., Vogt, H. G., Heyd, R., and Zamboglou, N. Does prophylactic treatment with proteolytic enzymes reduce acute toxicity of adjuvant pelvic irradiation? Results of a double-blind randomized trial PubMed
    2. 67848. Walker-Renard, P. Update on the medicinal management of phytobezoars. Am J Gastroenterol. 1993;88(10):1663-1666.
    3. 6. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.

    Nirmatrelvir, Ritonavir

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

Reported for Papain but not commonly for Nirmatrelvir, Ritonavir: stomach pain, a stuffy or runny nose, stomach upset and hives.

Effects for Nirmatrelvir, Ritonavir come from the ADVERSE REACTIONS section of its FDA label; effects for Papain 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.

Special populations

Papain in Pregnancy & Breastfeeding

Pregnancy Possibly Unsafe

When used orally. There is some concern that crude papain is teratogenic and embryotoxic.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

Everything else you take

See Every Supplement That Interacts With Nirmatrelvir, Ritonavir

This page covers Papain only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Nirmatrelvir, Ritonavir page lists 176 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Grapefruit (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 6 major · 134 moderate · 36 minor.

From our pharmacist’s overview on the Nirmatrelvir, Ritonavir page

“Paxlovid (nirmatrelvir and ritonavir) deserves genuine care around supplements, mostly because its ritonavir component strongly blocks the liver enzyme CYP3A4. The bulk of this list is made up of ingredients that enzyme normally clears, so their levels can climb unpredictably during the five-day course.”

Reviewed by 2 · Jul 18, 2026

Open the Nirmatrelvir, Ritonavir interaction page

One more smart check

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

We hold 3,790 real supplement products containing Papain, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Papain. Even though Papain itself has no known interaction with Nirmatrelvir, Ritonavir, 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 Papain and Nirmatrelvir, Ritonavir 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 Papain
Top 5%

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

29 days ago today
Medication Nirmatrelvir, Ritonavir
Top 10%

#150 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 Papain reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Papain and Nirmatrelvir, Ritonavir records this page draws on were last updated July 11, 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 Papain

What is Papain?

Papain
  • Digestive support for protein digestion
  • Wound cleaning (debridement of dead tissue)
  • Sore throat and inflammation
  • Sports injuries such as sprains
  • Skin conditions

Papain is a protein-digesting enzyme from the papaya plant that is used in digestive supplements and some topical products. While it has clear food and laboratory uses, strong human evidence for most health claims is limited, and it can cause allergic reactions or throat irritation. Check with a pharmacist or doctor before using it, especially if you have a latex or papaya allergy.

Carica papaya · Caricaceae · Latex (sap) from the unripe fruit; also derived from leaves · Capsules, tablets, chewable digestive enzyme blends, topical ointments and gels, meat tenderizer powder

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

Papain: dosing

There is no official, standardized dose for papain. The amount in supplements varies widely between products and is often measured in enzyme activity units rather than milligrams.The safest approach is to follow the directions on the product label and not exceed the recommended amount.

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

Read the full Papain monograph & all interactions
Medication

About Nirmatrelvir and Ritonavir

What Is Nirmatrelvir and Ritonavir Used For?

Brand name: Paxlovid

Paxlovid is approved to treat mild-to-moderate COVID-19 in adults who are at high risk of progressing to severe disease — meaning hospitalization or death. It is intended for people who already have symptoms and a confirmed COVID-19 diagnosis.

Paxlovid is not approved to prevent COVID-19 before or after exposure. It is a treatment, not a preventive medication.

See full Nirmatrelvir and Ritonavir drug information
Keep checking

Other Drugs & Papain

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

0Major
2Moderate
0Minor
2,827No known interaction
2 Moderate 2,827 No interaction
Moderate

2 interactions

No interaction 2,827 drugs checked — show the list

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

Showing the 60 most looked-up of 2,827 medications checked with no known interaction — see the full Papain list.

See the full Papain interactions page
See every supplement checked against Nirmatrelvir, Ritonavir, ranked by severity
Evidence & sources

Papain References

The 11 references that drive our Papain 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. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  2. Shaw D, Leon C, Kolev S, Murray V. Traditional remedies and food supplements: a 5-year toxicological study (1991-1995). Drug Saf 1997;17:342-56.
  3. Shuttleworth D, Hill S, Marks R, Connelly DM. Relief of experimentally induced pruritus with a novel eutectic mixture of local anaesthetic agents. Br J Dermatol 1988;119:535-40.
  4. Mansfield LE, Ting S, Haverly RW, Yoo TJ. The incidence and clinical implications of hypersensitivity to papain in an allergic population, confirmed by blinded oral challenge. Ann Allergy 1985;55:541-3.
  5. Martin, T., Uhder, K., Kurek, R., Roeddiger, S., Schneider, L., Vogt, H. G., Heyd, R., and Zamboglou, N. Does prophylactic treatment with proteolytic enzymes reduce acute toxicity of adjuvant pelvic irradiation? Results of a double-blind randomized trial PubMed
  6. Walker-Renard, P. Update on the medicinal management of phytobezoars. Am J Gastroenterol. 1993;88(10):1663-1666.
  7. Tymoszuk D, Wiszniewska M, Walusiak-Skorupa J. Papain-induced occupational rhinoconjunctivitis and asthma - A case report. Med Pr 2016;67(1):109-12. PubMed
  8. Soto-Mera MT, López-Rico MR, Filgueira JF, et al. Occupational allergy to papain. Allergy 2000;55(10):983-4. PubMed
  9. Tarlo SM, Shaikh W, Bell B, et al. Papain-induced allergic reactions. Clin Allergy 1978;8(3):207-15. PubMed
  10. Baur X, König G, Bencze K, Fruhmann G. Clinical symptoms and results of skin test, RAST and bronchial provocation test in thirty-three papain workers: Evidence for strong immunogenic potency and clinically relevant proteolytic e?ects of airborne papain. C
  11. Novey HS, Keenan WJ, Fairshter RD, Wells ID, Wilson AF, Culver BD. Pulmonary disease in workers exposed to papain: clinico-physiological and immunological studies. Clin Allergy 1980;10(6):721-31. 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 Papain and Nirmatrelvir, Ritonavir Together: Common Questions

Is it safe to take Papain with Nirmatrelvir, Ritonavir?
We do not list a known interaction between Papain and Nirmatrelvir, Ritonavir. 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 Papain and Nirmatrelvir, Ritonavir have any of the same side effects?
Yes — our sources link each of them separately to 2 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.
How was the Papain and Nirmatrelvir, Ritonavir combination checked?
Interactions in our licensed database are recorded against drug classes. Nirmatrelvir, Ritonavir is filed under 7 classifications, and Papain has documented interactions with 1 drug class — none of Nirmatrelvir, Ritonavir'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 Papain interact with any other medications?
Yes. Papain has 2 documented drug interactions in our database — Nirmatrelvir, Ritonavir 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 Nirmatrelvir, Ritonavir interact with any supplements?
Yes. Nirmatrelvir, Ritonavir has documented interactions with 176 supplements in our database — Papain is not one of them. The Nirmatrelvir, Ritonavir 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

Papain monograph Uses, safety profile, and every drug interaction in one place Nirmatrelvir and Ritonavir drug information The full plain-English guide to this medication Nirmatrelvir, Ritonavir supplement interactions Every supplement checked against Nirmatrelvir, Ritonavir, 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 11 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Nirmatrelvir, Ritonavir and Papain?

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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.