Drug & supplement interaction

Blue Cohosh + Nivolumab

Nivolumab brand name: Opdivo.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Blue Cohosh 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

Blue Cohosh 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 Blue Cohosh 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.

Blue Cohosh safety at a glance

Blue Cohosh overall Use caution Blue cohosh contains compounds that can affect the heart and has been linked to serious adverse events.
Pregnancy Likely Unsafe When used orally. Blue cohosh is a uterine stimulant and can induce labor. Several blue cohosh constituents, such as anagyrine and N-methylcytisine, are potenti... Read the full pregnancy detail
Breastfeeding Likely Unsafe When used orally. Blue cohosh is a uterine stimulant and can induce labor. Several blue cohosh constituents, such as anagyrine and N-methylcytisine, are potenti... Read the full breastfeeding detail

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 Nivolumab and Blue Cohosh? 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. Blue Cohosh has documented interactions with 3 drug classes — the most serious being antidiabetes drugs (moderate), antihypertensive drugs (moderate) and nicotine (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

Blue Cohosh Does Interact With Other Medications

Blue Cohosh has 259 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.

Taking anything else?

Check Another of Your Medications Against Blue Cohosh

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

What to actually watch for

No Interaction Found — But Data Suggests Blue Cohosh 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. 8 of them are worth acting on rather than waiting out — marked below.

  • A stroke or mini-stroke Worth acting on Additional detail

    Blue Cohosh

    “Orally, blue cohosh can cause significant adverse effects including mucous membrane irritation, stomach upset including diarrhea and cramping, chest pain (angina), hypertension, and hyperglycemia.

    Neonatal acute myocardial infarction (MI), congestive heart failure (CHF), and shock has occurred following maternal use of a blue cohosh combination product one month before delivery.”

    Blue Cohosh · Natural Medicines adverse-effect record, reported in abortion.

    6 sources cited
    1. 6002. Fetrow CW, Avila JR. Professional's Handbook of Complementary & Alternative Medicines. 1st ed. Springhouse, PA: Springhouse Corp., 1999.
    2. 566. Jones TK, Lawson BM. Profound neonatal congestive heart failure caused by maternal consumption of blue cohosh herbal medication. J Pediatr 1998;132:550-2. PubMed
    3. 3383. Edmunds J. Blue cohosh and newborn myocardial infarction? Midwifery Today Int Midwife 1999;52:34-5.
    4. 94534. Dugoua JJ, Perri D, Seely D, et al. Safety and efficacy of blue cohosh (Caulophyllum thalictroides) during pregnancy and lactation. Can J Clin Pharmacol. 2008;15(1):e66-73.
    5. 1122. McFarlin BL, Gibson MH, O'Rear J, Harman P. A national survey of herbal preparation use by nurse-midwives for labor stimulation. Review of the literature and recommendations for practice. J Nurse Midwifery 1999;44:205-16. PubMed
    6. 9492. Gunn TR, Wright IM. The use of black and blue cohosh in labour. N Z Med J 1996;109:410-1.

    “In one case, a mother was advised to drink a blue cohosh tea to induce labor. The infant experienced a seizure during delivery and 2 days later it was discovered that the infant was experiencing an evolving ischemic stroke. There is also another case report of severe complications, including seizures, in an infant whose mother was given an unknown dose of black and blue cohosh at 42 weeks gestation to induce labor.”

    Blue Cohosh · Natural Medicines adverse-effect record, reported in epilepsy.

    5 sources cited
    1. 12047. Finkel RS, Zarlengo KM. Blue cohosh and perinatal stroke. N Engl J Med 2004;351:302-3. PubMed
    2. 94534. Dugoua JJ, Perri D, Seely D, et al. Safety and efficacy of blue cohosh (Caulophyllum thalictroides) during pregnancy and lactation. Can J Clin Pharmacol. 2008;15(1):e66-73.
    3. 1122. McFarlin BL, Gibson MH, O'Rear J, Harman P. A national survey of herbal preparation use by nurse-midwives for labor stimulation. Review of the literature and recommendations for practice. J Nurse Midwifery 1999;44:205-16. PubMed
    4. 9492. Gunn TR, Wright IM. The use of black and blue cohosh in labour. N Z Med J 1996;109:410-1.
    5. 94934. Sirtori CR, Triolo M, Bosisio R, et al. Hypocholesterolaemic effects of lupin protein and pea protein/fibre combinations in moderately hypercholesterolaemic individuals. Br J Nutr 2012;107:1176-83. PubMed

    Nivolumab

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

  • A heart attack / Heart failure / Chest pain / Raised blood pressure Worth acting on Additional detail

    Blue Cohosh

    “Orally, blue cohosh can cause tachycardia, hypertension, and chest pain (angina). Neonatal acute myocardial infarction (MI), congestive heart failure (CHF), myocardial toxicity, and shock has occurred following maternal use of a blue cohosh combination product one month before delivery.”

    Blue Cohosh · Natural Medicines adverse-effect record, reported in angina.

    6 sources cited
    1. 36720. Rao, R. B. and Hoffman, R. S. Nicotinic toxicity from tincture of blue cohosh (Caulophyllum thalictroides) used as an abortifacient. Vet.Hum.Toxicol. 2002;44(4):221-222.
    2. 36724. Scott, C. C. and Chen, K. K. The pharmacological action of N-methylcytisine. The Journal of Pharmacology and Experimental Therapuetics 1943;79:334-339. DOI
    3. 94934. Sirtori CR, Triolo M, Bosisio R, et al. Hypocholesterolaemic effects of lupin protein and pea protein/fibre combinations in moderately hypercholesterolaemic individuals. Br J Nutr 2012;107:1176-83. PubMed
    4. 566. Jones TK, Lawson BM. Profound neonatal congestive heart failure caused by maternal consumption of blue cohosh herbal medication. J Pediatr 1998;132:550-2. PubMed
    5. 3383. Edmunds J. Blue cohosh and newborn myocardial infarction? Midwifery Today Int Midwife 1999;52:34-5.
    6. 12047. Finkel RS, Zarlengo KM. Blue cohosh and perinatal stroke. N Engl J Med 2004;351:302-3. PubMed

    Nivolumab

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

  • High blood sugar / Shortness of breath Worth acting on Additional detail

    Blue Cohosh

    Recorded for Blue Cohosh in the same Natural Medicines adverse-effect record shown under A stroke or mini-stroke above.

    Nivolumab

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

  • Kidney problems Worth acting on Additional detail

    Blue Cohosh

    “There is a case report of severe complications, including renal failure, in an infant whose mother was given an unknown dose of black and blue cohosh at 42 weeks gestation to induce labor.”

    Blue Cohosh · Natural Medicines adverse-effect record, reported in kidney failure.

    3 sources cited
    1. 1122. McFarlin BL, Gibson MH, O'Rear J, Harman P. A national survey of herbal preparation use by nurse-midwives for labor stimulation. Review of the literature and recommendations for practice. J Nurse Midwifery 1999;44:205-16. PubMed
    2. 9492. Gunn TR, Wright IM. The use of black and blue cohosh in labour. N Z Med J 1996;109:410-1.
    3. 94934. Sirtori CR, Triolo M, Bosisio R, et al. Hypocholesterolaemic effects of lupin protein and pea protein/fibre combinations in moderately hypercholesterolaemic individuals. Br J Nutr 2012;107:1176-83. PubMed

    Nivolumab

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

  • Muscle pain Additional detail

    Blue Cohosh

    Recorded for Blue Cohosh in the same Natural Medicines adverse-effect record shown under A stroke or mini-stroke above.

    Nivolumab

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

  • Stomach upset Additional detail

    Blue Cohosh

    “Orally, blue cohosh can cause mucous membrane irritation, stomach upset including diarrhea and cramping, nausea, vomiting, and abdominal pain.”

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

    1 source cited
    1. 36720. Rao, R. B. and Hoffman, R. S. Nicotinic toxicity from tincture of blue cohosh (Caulophyllum thalictroides) used as an abortifacient. Vet.Hum.Toxicol. 2002;44(4):221-222.

    Nivolumab

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

Showing the 10 most notable of 14 shared effects — ranked by how unusual each one is, not just whether both lists mention it.

Reported for Blue Cohosh but not commonly for Nivolumab: a fast or pounding heartbeat, seizures and sweating.

Effects for Nivolumab come from the ADVERSE REACTIONS section of its FDA label; effects for Blue Cohosh 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.

Special populations

Blue Cohosh in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Unsafe

When used orally. Blue cohosh is a uterine stimulant and can induce labor. Several blue cohosh constituents, such as anagyrine and N-methylcytisine, are potentially teratogenic and might cause congenital malformations in newborns. Use of blue cohosh near term can cause life-threatening toxicity in the infant, as well as severe toxicity in the mother. Many midwives still use blue cohosh to facilitate delivery. This dangerous practice should be avoided.

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

How to take them

Some Nivolumab Products Have a Food Rule — Blue Cohosh Should Not Break It

At least one FDA label for a product containing Nivolumab says to take it on an empty stomach. Most supplements — Blue Cohosh 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 Blue Cohosh 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 Blue Cohosh 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 Blue Cohosh as Part of a Dietary Supplement Product? Check It for Interactions

We hold 126 real supplement products containing Blue Cohosh, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Blue Cohosh. Even though Blue Cohosh 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 Blue Cohosh 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 Blue Cohosh
Top half

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

29 days ago today
Medication Nivolumab
Top 25%

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

What is Blue Cohosh?

  • Inducing labor or starting menstruation
  • Menstrual cramps and irregular periods
  • Symptoms of menopause
  • Pelvic or uterine discomfort
  • Traditional Native American remedy

Blue cohosh is a traditional herb historically used by Native Americans and midwives to bring on labor or menstruation, but it carries serious safety concerns, especially for the heart and during pregnancy. There is very little reliable human evidence that it works, and reports of harm—including serious problems in newborns—make it an herb most people should avoid without close professional supervision.

Caulophyllum thalictroides · Berberidaceae · Root and rhizome · Capsules, tinctures, dried root, tea, liquid extracts

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

Blue Cohosh: dosing

There is no well-established, standardized safe dose for blue cohosh. Products vary widely in strength, and the herb's safety concerns make general dosing recommendations inappropriate.Because of the risk of serious side effects, we do not provide specific amounts.

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

Read the full Blue Cohosh 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 & Blue Cohosh

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

0Major
259Moderate
0Minor
2,570No known interaction
Moderate

259 interactions

Showing 60 of 259 moderate interactions — see all 259 on the Blue Cohosh page.

No interaction 2,570 drugs checked — show the list
Evidence & sources

Blue Cohosh References

The 16 references that drive our Blue Cohosh 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. Jones TK, Lawson BM. Profound neonatal congestive heart failure caused by maternal consumption of blue cohosh herbal medication. J Pediatr 1998;132:550-2. PubMed
  2. McFarlin BL, Gibson MH, O'Rear J, Harman P. A national survey of herbal preparation use by nurse-midwives for labor stimulation. Review of the literature and recommendations for practice. J Nurse Midwifery 1999;44:205-16. PubMed
  3. Wright IM. Neonatal effects of maternal consumption of blue cohosh. J Pediatr 1999;134:384-5. DOI
  4. Edmunds J. Blue cohosh and newborn myocardial infarction? Midwifery Today Int Midwife 1999;52:34-5.
  5. Fetrow CW, Avila JR. Professional's Handbook of Complementary & Alternative Medicines. 1st ed. Springhouse, PA: Springhouse Corp., 1999.
  6. Irikura B, Kennelly E. American Health Consultants. Blue Cohosh: a word of caution. 1999. Available at: http://www.ahcmedia.com/articles/50424-blue-cohosh-a-word-of-caution.
  7. Gunn TR, Wright IM. The use of black and blue cohosh in labour. N Z Med J 1996;109:410-1.
  8. Baillie N, Rasmussen P. Black and blue cohosh in labour. N Z Med J 1997;110:20-1.
  9. Finkel RS, Zarlengo KM. Blue cohosh and perinatal stroke. N Engl J Med 2004;351:302-3. PubMed
  10. Kennelly, E. J., Flynn, T. J., Mazzola, E. P., Roach, J. A., McCloud, T. G., Danford, D. E., and Betz, J. M. Detecting potential teratogenic alkaloids from blue cohosh rhizomes using an in vitro rat embryo culture. J.Nat.Prod. 1999;62(10):1385-1389. PubMed
  11. Rao, R. B. and Hoffman, R. S. Nicotinic toxicity from tincture of blue cohosh (Caulophyllum thalictroides) used as an abortifacient. Vet.Hum.Toxicol. 2002;44(4):221-222.
  12. Gunn, T. R. and Wright, I. M. The use of black and blue cohosh in labour. N.Z Med J 10-25-1996;109(1032):410-411.
  13. Scott, C. C. and Chen, K. K. The pharmacological action of N-methylcytisine. The Journal of Pharmacology and Experimental Therapuetics 1943;79:334-339. DOI
  14. Low, D. T. Blue cohosh and neonatal myocardial toxicity. Journal of the American Herbalists Guild 2001;2(2):9-10.
  15. Dugoua JJ, Perri D, Seely D, et al. Safety and efficacy of blue cohosh (Caulophyllum thalictroides) during pregnancy and lactation. Can J Clin Pharmacol. 2008;15(1):e66-73.

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 Blue Cohosh and Nivolumab Together: Common Questions

Is it safe to take Blue Cohosh with Nivolumab?
We do not list a known interaction between Blue Cohosh 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 Blue Cohosh and Nivolumab have any of the same side effects?
Yes — our sources link each of them separately to 10 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 Blue Cohosh 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 Blue Cohosh 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 Blue Cohosh and Nivolumab combination checked?
Interactions in our licensed database are recorded against drug classes. Nivolumab is filed under 1 classification, and Blue Cohosh has documented interactions with 3 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 Blue Cohosh interact with any other medications?
Yes. Blue Cohosh has 259 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 — Blue Cohosh 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

Still Have a Question About Nivolumab and Blue Cohosh?

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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.