Drug & supplement interaction

Costus + Metoprolol

Metoprolol brand names: Lopressor, Toprol XL.

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 Costus and Metoprolol 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 Metoprolol 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

Costus and Metoprolol

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 Metoprolol and Costus 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.

Worth understanding: our licensed dataset holds no drug-interaction record for Costus at all — not against Metoprolol, 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.

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.

Costus safety at a glance

Costus overall Use caution Human safety data are limited, and quality and purity of products vary widely.
Pregnancy Avoid Traditionally believed to stimulate the uterus, so it is best avoided during pregnancy.
Breastfeeding Avoid There is not enough safety information, so avoid use while breastfeeding.

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

Still wondering about combining Metoprolol and Costus? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Costus and Metoprolol 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 taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • A skin rash Additional detail

    Costus

    “Orally and topically, costus might cause allergic reactions, including contact dermatitis (11,73140,73155,73281,73284,73288).”

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

    6 sources cited
    1. 11. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
    2. 73140. Marzulli, F. N. and Maibach, H. I. Effects of vehicles and elicitation concentration in contact dermatitis testing. I. Experimental contact sensitization in humans. Contact Dermatitis 1976;2(6):325-329. PubMed
    3. 73155. Mitchell, J. C. Contact hypersensitivity to some perfume materials. Contact Dermatitis 1975;1(4):196-199. PubMed
    4. 73281. Benezra, C. and Epstein, W. L. Molecular recognition patterns of sesquiterpene lactones in costus-sensitive patients. Contact Dermatitis 1986;15(4):223-230. PubMed
    5. 73284. Mitchell, J. C. and Epstein, W. L. Contact hypersensitivity to a perfume material, Costus Absolute. The role of sesquiterpene lactones. Arch.Dermatol 1974;110(6):871-873. DOI
    6. 73288. Cheminat, A., Stampf, J. L., Benezra, C., Farrall, M. J., and Frechet, J. M. Allergic contact dermatitis to costus: removal of haptens with polymers. Acta Derm.Venereol. 1981;61(6):525-529. DOI

    Metoprolol

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

Reported for Costus but not commonly for Metoprolol: an allergic reaction.

Effects for Metoprolol come from the ADVERSE REACTIONS section of its FDA label; effects for Costus 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 Metoprolol Products Have a Food Rule — Costus Should Not Break It

At least one FDA label for a product containing Metoprolol says to take it with food. If you take Costus on an empty stomach out of habit, keep them separate — and take Metoprolol 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 Metoprolol 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.

Administer once daily with food or after a meal.

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

From our Q&A

Questions About Costus or Metoprolol

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Costus or Metoprolol, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Metoprolol

This page covers Costus only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Metoprolol page lists 183 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Indian Snakeroot (major) and Tyramine (major).

By severity: 5 major · 152 moderate · 26 minor.

From our pharmacist’s overview on the Metoprolol page

“With metoprolol (Lopressor, Toprol XL), a beta-blocker for high blood pressure and heart problems, these interactions deserve genuine care, starting with the five rated major. Most entries pull blood pressure one way or the other: many supplements add to metoprolol's lowering effect and can drop pressure too far, while a few, tyramine…”

Reviewed by 2 · Jul 18, 2026

Open the Metoprolol interaction page

One more smart check

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

We hold 113 real supplement products containing Costus, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Costus. Even though Costus itself has no known interaction with Metoprolol, 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 Costus and Metoprolol 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 Costus
Top half

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

29 days ago today
Medication Metoprolol
Top 10

#7 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 Costus reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Costus and Metoprolol 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 Costus

What is Costus?

  • Digestive upset and gas
  • Cough and breathing complaints
  • Skin conditions (topical)
  • Worm and parasite remedies (traditional)
  • General tonic in traditional medicine

Costus (Saussurea costus) is a root used in Ayurvedic, Unani, and traditional Chinese medicine, mostly for digestive and respiratory complaints. High-quality human evidence is very limited, so its benefits are not well proven. Talk with a pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Saussurea costus · Asteraceae · Dried roots and root essential oil · Dried root powder, capsules, decoctions (teas), essential oil, and topical pastes

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

Costus: dosing

There is no well-established or standardized dose of costus for any health condition. Traditional preparations vary widely, and the strength of commercial products is not consistent.If you choose to use a costus product, follow the directions on the label and do not exceed them. The essential oil is very concentrated and should not be taken by mouth without professional guidance.

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

Read the full Costus monograph & all interactions
Medication

About Metoprolol

What Is Metoprolol Used For?

Brand names: Lopressor, Toprol XL

Metoprolol is used to treat several heart and blood pressure conditions. Metoprolol succinate extended-release tablets (including Toprol-XL) are approved for high blood pressure, angina pectoris (chest pain from the heart), and heart failure. Metoprolol tartrate tablets (including Lopressor) are approved for high blood pressure, angina, and — when used alongside intravenous metoprolol — to reduce the risk of cardiovascular death after a definite or suspected heart attack.

Metoprolol tartrate injection (intravenous form) is used in hemodynamically stable patients with a definite or suspected acute heart attack to reduce cardiovascular death, and is followed by oral metoprolol therapy. Lowering blood pressure with metoprolol reduces the risk of strokes and heart attacks.

Most-Reported Side Effects for Metoprolol

From FAERS, the FDA’s public side-effect reporting system (0 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 23,416 reports
Dyspnea 20,183 reports
Diarrhea 19,912 reports
Nausea 19,659 reports
Dizziness 16,726 reports
See full Metoprolol drug information
Keep checking

Other Drugs & Costus

Browse every other medication we’ve checked against Costus — 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 Costus 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 Costus list.

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

Costus References

The 6 references that drive our Costus 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. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
  2. Marzulli, F. N. and Maibach, H. I. Effects of vehicles and elicitation concentration in contact dermatitis testing. I. Experimental contact sensitization in humans. Contact Dermatitis 1976;2(6):325-329. PubMed
  3. Mitchell, J. C. Contact hypersensitivity to some perfume materials. Contact Dermatitis 1975;1(4):196-199. PubMed
  4. Benezra, C. and Epstein, W. L. Molecular recognition patterns of sesquiterpene lactones in costus-sensitive patients. Contact Dermatitis 1986;15(4):223-230. PubMed
  5. Mitchell, J. C. and Epstein, W. L. Contact hypersensitivity to a perfume material, Costus Absolute. The role of sesquiterpene lactones. Arch.Dermatol 1974;110(6):871-873. DOI
  6. Cheminat, A., Stampf, J. L., Benezra, C., Farrall, M. J., and Frechet, J. M. Allergic contact dermatitis to costus: removal of haptens with polymers. Acta Derm.Venereol. 1981;61(6):525-529. DOI

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 Costus and Metoprolol Together: Common Questions

Is it safe to take Costus with Metoprolol?
We do not list a known interaction between Costus and Metoprolol. 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 Costus and Metoprolol 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.
Should I take Costus and Metoprolol at the same time of day?
At least one FDA label for a product containing Metoprolol says to take it with food. If you take Costus on an empty stomach out of habit, keep them separate and take Metoprolol with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Metoprolol products can differ — so check the directions on your own box. This is about absorption, not an interaction.
Does Metoprolol interact with any supplements?
Yes. Metoprolol has documented interactions with 183 supplements in our database — Costus is not one of them. The Metoprolol 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

Costus monograph Uses, safety profile, and every drug interaction in one place Metoprolol drug information The full plain-English guide to this medication Metoprolol supplement interactions Every supplement checked against Metoprolol, 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 6 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Metoprolol and Costus?

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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.