Drug & supplement interaction

Fish Therapy + 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 Fish Therapy 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

Fish Therapy 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 Fish Therapy in our sources. This does not guarantee that the combination is completely free of risk — research on Fish Therapy alongside specific medications may be limited.

Worth understanding: our licensed dataset holds no drug-interaction record for Fish Therapy at all — not against Nirmatrelvir, Ritonavir, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

Fish Therapy is a treatment rather than something you take. Tell whoever provides it which medicines you use, and ask your prescriber whether it is appropriate for your health and treatment. 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.

Fish Therapy safety at a glance

Fish Therapy overall Use caution Hygiene and infection risks make this a cautious choice, especially with shared water.
Pregnancy Use caution Not studied in pregnancy; avoid due to infection risk unless cleared by your doctor.
Breastfeeding Use caution No safety data; infection risk makes caution reasonable while breastfeeding.

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

Still wondering about combining Nirmatrelvir, Ritonavir and Fish Therapy? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Fish Therapy and Nirmatrelvir, Ritonavir May Share a Side Effect

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 having Fish Therapy while taking the medicine 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.

  • A higher chance of infection Worth acting on Additional detail

    Fish Therapy

    “Multiple case reports suggest that fish therapy can increase the risk for bacterial infection. Studies of fish therapy water have identified multiple bacteria capable of causing disease. It is currently not possible to adequately sterilize the water without killing the fish. Additionally, when performed in a spa or salon setting, pedicure tubs cannot be adequately cleaned when fish are present.”

    Fish Therapy · Natural Medicines adverse-effect record, reported in dermatitis.

    6 sources cited
    1. 103109. Vanhooteghem O, Anseeuw D, Michel C, et al. Fish Pedicure-induced Aeromonas sobria Superficial Necrotic Bullous Dermatitis in a Previously Undiagnosed Diabetes Patient. What are the Risks of Fish Pedicure for Public Health? BJMMR. 2015;10(12):1-10. DOI
    2. 103110. Veraldi S, Nazzaro G, Çuka E. Staphylococcus aureus infection of the feet following fish pedicure. Infection. 2014 Oct;42(5):925-6. PubMed
    3. 103111. Sugimoto K, Frei R, Graber P. Methicillin-resistant Staphylococcus aureus foot infection after fish pedicure. Infection. 2013 Oct;41(5):1013-5. PubMed
    4. 103112. Vanhooteghem O, Theate I. Fish pedicure-induced foot mycobacteriosis infection due to Mycobacterium marinum: a first case report. Eur J Dermatol. 2017 Jun 1;27(3):299-300. PubMed
    5. 103108. Lipner SR. Onychomadesis Following a Fish Pedicure. JAMA Dermatol. 2018 Sep 1;154(9):1091-1092. PubMed
    6. 103113. US Centers for Disease Control (CDC). Fish Pedicures and Fish Spas. August 2, 2016. Available at: https://www.cdc.gov/healthywater/hygiene/body/fish_pedicures.html. Accessed on June 15, 2020.

    Nirmatrelvir, Ritonavir

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

Reported for Fish Therapy but not commonly for Nirmatrelvir, Ritonavir: a skin rash, liver problems and swelling.

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

Everything else you take

See Every Supplement That Interacts With Nirmatrelvir, Ritonavir

This page covers Fish Therapy 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

How much people look this up

Where Fish Therapy 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 Fish Therapy
Steady interest

#811 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 Fish Therapy reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Fish Therapy and Nirmatrelvir, Ritonavir 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 .
Treatment approach

About Fish Therapy

What is Fish Therapy?

  • Psoriasis
  • Skin exfoliation and smoothing
  • Eczema and dry skin
  • Cosmetic foot care (pedicure)
  • General relaxation

Fish therapy (also called ichthyotherapy or a 'fish pedicure') uses small Garra rufa fish to nibble away dead skin, and it is mostly used cosmetically or for skin conditions like psoriasis. Evidence that it treats any medical condition is very limited, and there are real infection and hygiene concerns. If you have a skin condition, talk with a dermatologist before trying it.

Live fish (commonly Garra rufa); the whole animal used in skin-immersion baths · Spa fish baths (foot or full-body immersion with Garra rufa fish)

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

Fish Therapy: dosing

There is no standard 'dose' for fish therapy, since it is a spa procedure rather than a supplement you take. Sessions are usually a set number of minutes in a spa setting.If you choose to try it, only use a reputable, licensed facility that follows strict hygiene rules, and never share water with someone who has a skin infection.

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

Read the full Fish Therapy 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 & Fish Therapy

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

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

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

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Fish Therapy list.

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

Fish Therapy References

The 8 references that drive our Fish Therapy 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. Grassberger M, Hoch W. Ichthyotherapy as alternative treatment for patients with psoriasis: a pilot study. Evid Based Complement Alternat Med. 2006 Dec;3(4):483-8. PubMed
  2. Lipner SR. Onychomadesis Following a Fish Pedicure. JAMA Dermatol. 2018 Sep 1;154(9):1091-1092. PubMed
  3. Vanhooteghem O, Anseeuw D, Michel C, et al. Fish Pedicure-induced Aeromonas sobria Superficial Necrotic Bullous Dermatitis in a Previously Undiagnosed Diabetes Patient. What are the Risks of Fish Pedicure for Public Health? BJMMR. 2015;10(12):1-10. DOI
  4. Veraldi S, Nazzaro G, Çuka E. Staphylococcus aureus infection of the feet following fish pedicure. Infection. 2014 Oct;42(5):925-6. PubMed
  5. Sugimoto K, Frei R, Graber P. Methicillin-resistant Staphylococcus aureus foot infection after fish pedicure. Infection. 2013 Oct;41(5):1013-5. PubMed
  6. Vanhooteghem O, Theate I. Fish pedicure-induced foot mycobacteriosis infection due to Mycobacterium marinum: a first case report. Eur J Dermatol. 2017 Jun 1;27(3):299-300. PubMed
  7. US Centers for Disease Control (CDC). Fish Pedicures and Fish Spas. August 2, 2016. Available at: https://www.cdc.gov/healthywater/hygiene/body/fish_pedicures.html. Accessed on June 15, 2020.
  8. Vanhooteghem O, Theate I, De Schaetzen V. Periungual Mycobacterium marinum Infection following a Fish Manicure. Skin Appendage Disord. 2021 Aug;7(5):393-396.

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

Having Fish Therapy While Taking Nirmatrelvir, Ritonavir: Common Questions

Is it safe to have Fish Therapy while taking Nirmatrelvir, Ritonavir?
We do not list a known interaction between Fish Therapy 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 Fish Therapy and Nirmatrelvir, Ritonavir have any of the same side effects?
Yes — our sources link each of them separately to one 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.
Does Nirmatrelvir, Ritonavir interact with any supplements?
Yes. Nirmatrelvir, Ritonavir has documented interactions with 176 supplements in our database — Fish Therapy 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

Fish Therapy 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 8 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Nirmatrelvir, Ritonavir and Fish Therapy?

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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.