Drug & supplement interaction

Catnip + Nivolumab

Nivolumab brand name: Opdivo.

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 Catnip and Nivolumab 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 Nivolumab 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

Catnip and Nivolumab

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 Nivolumab and Catnip 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.

Catnip safety at a glance

Catnip overall Use caution Likely fine for most adults in tea amounts, but human safety data are limited.
Pregnancy Avoid Avoid during pregnancy, as it may stimulate the uterus and safety is not established.
Breastfeeding Avoid Not enough safety information is available, so it is best avoided.

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

Still wondering about combining Nivolumab and Catnip? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Nivolumab

Interactions in our licensed database are recorded against drug classes, not just single drug names. Nivolumab is filed under a single classification — antineoplastics. Catnip has documented interactions with 2 drug classes — the most serious being cns depressants (moderate) and lithium (moderate) — and none of Nivolumab’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

Catnip Does Interact With Other Medications

Catnip has 248 moderate known drug interactions in our database — Nivolumab isn’t one of them. If you take anything else, check it against the full list below.

Moderate 248 No known interaction 2,582 (incl. Nivolumab)
Taking anything else?

Check Another of Your Medications Against Catnip

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

What to actually watch for

No Interaction Found — But Data Suggests Catnip and Nivolumab 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.

  • Tiredness / Headache reported in 4.3% of FDA reports for Nivolumab Additional detail

    Catnip

    “Orally, taking too much catnip may result in headache and malaise (6). In one case, a toddler developed a stomachache and irritability, followed by lethargy and a hypnotic state, after ingesting raisins soaked in catnip tea and chewing on the tea bag (5,2596).”

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

    3 sources cited
    1. 6. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
    2. 5. Foster S, Tyler VE. Tyler's Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies. 3rd ed., Binghamton, NY: Haworth Herbal Press, 1993.
    3. 2596. Osterhoudt KC, Lee SK, Callahan JM, Henretig FM. Catnip and the alteration of human consciousness. Vet Hum Toxicol 1997;39:373-5.

    Nivolumab

    Listed in the ADVERSE REACTIONS section of the FDA label for Nivolumab, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

  • Vomiting Additional detail

    Catnip

    “Orally, large amounts of catnip might cause stomachache and vomiting (6,2596).”

    Catnip · Natural Medicines adverse-effect record, reported in nausea and vomiting.

    2 sources cited
    1. 6. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
    2. 2596. Osterhoudt KC, Lee SK, Callahan JM, Henretig FM. Catnip and the alteration of human consciousness. Vet Hum Toxicol 1997;39:373-5.

    Nivolumab

    Listed in the ADVERSE REACTIONS section of the FDA label for Nivolumab. Read the label on DailyMed ›

Reported for Catnip but not commonly for Nivolumab: mood changes or irritability.

Effects for Nivolumab come from the ADVERSE REACTIONS section of its FDA label; effects for Catnip come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 96,645 voluntary FDA FAERS reports for Nivolumab that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. 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 Nivolumab Products Have a Food Rule — Catnip Should Not Break It

At least one FDA label for a product containing Nivolumab says to take it on an empty stomach. Most supplements — Catnip included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Nivolumab on its own and move Catnip to a meal later in the day.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Nivolumab 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.

Table 2: Recommended Dosages of Intravenous OPDIVO in Combination with Other Therapeutic Agents Indication Recommended OPDIVO Dosage Duration of Therapy Unresectable or metastatic melanoma 1 mg/kg every 3 weeks with ipilimumab 3 mg/kg In combination with ipilimumab for a maximum of 4 doses or until unacceptable toxicity, whichever occurs earlier Adult patients and pediatric patients aged 12 years

From the Dosage and Administration section of the FDA label we read for Nivolumab — 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 Nivolumab

This page covers Catnip only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Nivolumab page lists 1 supplement it has a documented interaction with, worst first, each one explained.

The most serious there right now: American Pawpaw (minor).

By severity: 1 minor.

From our pharmacist’s overview on the Nivolumab page

“Nivolumab (Opdivo) is an immunotherapy infusion that trains the body's own immune system to recognize and attack cancer cells, the kind of drug you might expect to carry a long list of supplement warnings. It does not.”

Reviewed by 2 · Jul 18, 2026

Open the Nivolumab interaction page

One more smart check

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

We hold 295 real supplement products containing Catnip, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Catnip. Even though Catnip itself has no known interaction with Nivolumab, 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 Catnip and Nivolumab 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 Catnip
Top half

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

29 days ago today
Medication Nivolumab
Top 25%

#353 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 Catnip reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Catnip and Nivolumab 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 Catnip

What is Catnip?

Catnip
  • Sleep and insomnia
  • Anxiety and stress
  • Digestive upset
  • Cold and flu symptoms
  • Insect repellent

Catnip is a mint-family herb most often used as a calming tea for sleep, anxiety, and minor digestive upset, but solid human research supporting these uses is lacking. It is generally considered fairly safe in small culinary or tea amounts for most adults, but it should be avoided during pregnancy and used cautiously otherwise. Talk to your pharmacist or doctor before using it, especially if you take medications or have a health condition.

Nepeta cataria · Lamiaceae · Leaves, flowers, and essential oil · Tea, capsules, tincture, dried herb, essential oil

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

Catnip: dosing

There is no well-established standard dose for catnip. Amounts used in traditional practice vary widely, and reliable dosing guidelines from clinical studies are not available.The safest approach is to follow the directions on the product label and not exceed the recommended amount.

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

Read the full Catnip monograph & all interactions
Medication

About Nivolumab Injection

What Is Nivolumab Injection Used For?

Brand name: Opdivo

Opdivo (nivolumab) is used to treat many types of cancer in adults, and some in patients 12 years and older. It can be used alone or in combination with other therapies depending on the cancer type and stage. Cancers it treats include melanoma (including after surgery to reduce the chance of the cancer coming back), non-small cell lung cancer, malignant pleural mesothelioma, advanced renal cell carcinoma (kidney cancer), classical Hodgkin lymphoma, squamous cell carcinoma of the head and neck, urothelial carcinoma (bladder cancer), colorectal cancer with specific genetic features (MSI-H or dMMR), hepatocellular carcinoma (liver cancer), esophageal cancer, gastroesophageal junction cancer, and gastric (stomach) cancer.

Some uses require the tumor to test positive for a protein called PD-L1, and some are specific to certain stages of disease or prior treatments received. Your oncologist will determine which use applies to your situation.

Most-Reported Side Effects for Nivolumab

From FAERS, the FDA’s public side-effect reporting system (96,645 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Malignant neoplasm progression 9,878 reports
Diarrhea 5,251 reports
Fatigue 4,195 reports
Fever 3,721 reports
Nausea 3,182 reports
See full Nivolumab Injection drug information
Keep checking

Other Drugs & Catnip

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

0Major
248Moderate
0Minor
2,581No known interaction
248 Moderate 2,581 No interaction
Moderate

248 interactions

Showing 60 of 248 moderate interactions — see all 248 on the Catnip page.

No interaction 2,581 drugs checked — show the list

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

Showing the 60 most looked-up of 2,581 medications checked with no known interaction — see the full Catnip list.

See the full Catnip interactions page
See every supplement checked against Nivolumab, ranked by severity
Evidence & sources

Catnip References

The 7 references that drive our Catnip 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. Foster S, Tyler VE. Tyler's Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies. 3rd ed., Binghamton, NY: Haworth Herbal Press, 1993.
  2. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  3. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  4. Osterhoudt KC, Lee SK, Callahan JM, Henretig FM. Catnip and the alteration of human consciousness. Vet Hum Toxicol 1997;39:373-5.
  5. Sherry, C. J. and Hunter, P. S. The effect of an ethanol extract of catnip (Nepeta cataria) on the behavior of the young chick. Experientia 2-15-1979;35(2):237-238. PubMed
  6. Harney, J. W., Barofsky, I. M., and Leary, J. D. Behavioral and toxicological studies of cyclopentanoid monoterpenes from Nepeta cataria. Lloydia. 1978;41(4):367-374.
  7. Massoco, C. O., Silva, M. R., Gorniak, S. L., Spinosa, M. S., and Bernardi, M. M. Behavioral effects of acute and long-term administration of catnip (Nepeta cataria) in mice. Vet.Hum.Toxicol 1995;37(6):530-533.

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 Catnip and Nivolumab Together: Common Questions

Is it safe to take Catnip with Nivolumab?
We do not list a known interaction between Catnip and Nivolumab. 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 Catnip and Nivolumab 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 Catnip and Nivolumab at the same time of day?
At least one FDA label for a product containing Nivolumab says to take it on an empty stomach, and supplements are usually taken with a meal — so taking them together at breakfast is the easy mistake. Where that applies, keep Nivolumab on its own and move Catnip to a meal later in the day. Food instructions belong to the product rather than the ingredient, so check the directions on your own box. This is about absorption, not an interaction.
How was the Catnip and Nivolumab combination checked?
Interactions in our licensed database are recorded against drug classes. Nivolumab is filed under 1 classification, and Catnip has documented interactions with 2 drug classes — none of Nivolumab'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 Catnip interact with any other medications?
Yes. Catnip has 248 documented drug interactions in our database — Nivolumab 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 Nivolumab interact with any supplements?
Yes. Nivolumab has documented interactions with 1 supplement in our database — Catnip is not one of them. The Nivolumab 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

Catnip monograph Uses, safety profile, and every drug interaction in one place Nivolumab Injection drug information The full plain-English guide to this medication Nivolumab supplement interactions Every supplement checked against Nivolumab, 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 7 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Nivolumab and Catnip?

Our pharmacists answer your medication & supplement questions — free.

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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.