Drug & supplement interaction

Quercetin + Colestipol

Colestipol brand name: Colestid.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Quercetin and Colestipol 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 Colestipol 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

Quercetin and Colestipol

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 Colestipol and Quercetin 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.

Quercetin safety at a glance

Quercetin overall Use caution Generally well tolerated in food and typical supplement amounts, but high doses and long-term safety are not well studied.
Pregnancy Avoid Not enough safety information exists; avoid supplemental doses during pregnancy.
Breastfeeding Avoid Not enough safety information exists; avoid supplemental doses while breastfeeding.

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

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

Why No Interaction Is Listed for Colestipol

Interactions in our licensed database are recorded against drug classes, not just single drug names. Colestipol is filed under 2 classifications — bile acid sequestrants, oral drugs. Quercetin has documented interactions with 21 drug classes — the most serious being antidiabetes drugs (moderate), antihypertensive drugs (moderate) and cyclosporine (neoral, sandimmune) (moderate) — and none of Colestipol’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

Quercetin Does Interact With Other Medications

Quercetin has 1,169 moderate known drug interactions in our database — Colestipol 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 Quercetin

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

What to actually watch for

No Interaction Found — But Data Suggests Quercetin and Colestipol 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.

  • Shortness of breath Worth acting on Additional detail

    Quercetin

    “Intravenous administration of quercetin at doses as high as 2000 mg/m2 is associated with dyspnea that may persist for up to 5 minutes.”

    Quercetin · Natural Medicines adverse-effect record, reported in myasthenia gravis.

    1 source cited
    1. 9564. Ferry DR, Smith A, Malkhandi J, et al. Phase I clinical trial of the flavonoid quercetin: Pharmacokinetics and evidence for in vivo tyrosine kinase inhibition. Clin Cancer Res 1996;2:659-67..

    Colestipol

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

  • Vomiting / Nausea Additional detail

    Quercetin

    “Intravenous administration of quercetin is associated with nausea and vomiting.”

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

    1 source cited
    1. 9564. Ferry DR, Smith A, Malkhandi J, et al. Phase I clinical trial of the flavonoid quercetin: Pharmacokinetics and evidence for in vivo tyrosine kinase inhibition. Clin Cancer Res 1996;2:659-67..

    Colestipol

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

  • Headache Additional detail

    Quercetin

    “Orally, quercetin may cause headache and tingling of the extremities. Intravenously, quercetin may cause pain at the injection site. Injection pain can be minimized by premedicating patients with 10 mg of morphine and administering amounts greater than 945 mg/m2 over 5 minutes. In addition, intravenous administration of quercetin is associated with flushing and sweating.”

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

    3 sources cited
    1. 481. Shoskes DA, Zeitlin SI, Shahed A, Rajfer J. Quercetin in men with category III chronic prostatitis: A preliminary prospective, double-blind, placebo-controlled trial. Urol 1999;54:960-3. PubMed
    2. 111500. Nambiar A, Kellogg D 3rd, Justice J, et al. Senolytics dasatinib and quercetin in idiopathic pulmonary fibrosis: results of a phase I, single-blind, single-center, randomized, placebo-controlled pilot trial on feasibility and tolerability. EBioMedicine 20 PubMed
    3. 9564. Ferry DR, Smith A, Malkhandi J, et al. Phase I clinical trial of the flavonoid quercetin: Pharmacokinetics and evidence for in vivo tyrosine kinase inhibition. Clin Cancer Res 1996;2:659-67..

    Colestipol

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

Reported for Quercetin but not commonly for Colestipol: kidney problems, numbness or tingling, sweating and flushing.

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

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

Patients should take other drugs at least one hour before or four hours after colestipol hydrochloride tablets to minimize possible interference with their absorption.

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

Overlapping uses

What Colestipol Is Prescribed For, and What Quercetin Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Colestipol is a prescription medicine with approved uses on its FDA label. Quercetin is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Colestipol is prescribed for: Colestipol — available as oral suspension and tablets under brands including Colestid, Flavored Colestid, and Colestipol Hydrochloride — is used as part of a broader treatment plan (including diet) to lower elevated LDL cholesterol in adults with primary hypercholesterolemia (a condition where LDL cholesterol stays high despite dietary changes). It is not a standalone fix. Diet, weight management, and other lifestyle changes come first, and colestipol is added when those steps alone aren't enough to reach target LDL levels.

Quercetin has been studied for:

  • Hypercholesterolemia studied, not established Quercetin has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Quercetin for hypercholesterolemia

    It is unclear if oral quercetin is beneficial for improving cholesterol levels.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Colestipol on your own; if you are taking Quercetin for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

From our Q&A

Questions About Quercetin or Colestipol

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Quercetin or Colestipol, 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 Colestipol

This page covers Quercetin only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Colestipol page lists 18 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Coffee Charcoal (moderate), European Mandrake (moderate), Glucomannan (moderate) and Guar Gum (moderate).

By severity: 1 major · 8 moderate · 9 minor.

From our pharmacist’s overview on the Colestipol page

“Take colestipol (Colestid), a cholesterol drug that works by trapping bile acids in your gut, and nearly every one of the 18 supplement interactions on file comes down to absorption. Only one rates major, activated charcoal, and it belongs at the top of your reading.”

Reviewed by 2 · Jul 18, 2026

Open the Colestipol interaction page

One more smart check

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

We hold 4,589 real supplement products containing Quercetin, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Quercetin. Even though Quercetin itself has no known interaction with Colestipol, 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 Quercetin and Colestipol 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 Quercetin
Top 5%

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

29 days ago today
Medication Colestipol
Top half

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

What is Quercetin?

Quercetin
  • Seasonal allergies
  • Antioxidant support
  • Heart and blood pressure health
  • Anti-inflammatory support
  • Immune support
  • Exercise recovery

Quercetin is a plant flavonoid with antioxidant and anti-inflammatory properties found in many common foods and sold as a supplement. While early research is interesting for allergies, blood pressure, and inflammation, strong human evidence is limited for most uses. It is generally well tolerated in food amounts, but talk to your pharmacist or doctor before taking high-dose supplements.

Found naturally in many plants, fruits, and vegetables (such as onions, apples, berries, and capers) · Capsules, tablets, powders, softgels; often combined with vitamin C or bromelain

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

Quercetin: dosing

There is no official or standardized dose of quercetin. Supplement products vary widely in their strength and in what they are combined with.The best advice is to follow the dose on the product label and not exceed it unless a healthcare provider tells you to. More is not always better, and very high doses are not recommended.

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

Read the full Quercetin monograph & all interactions
Medication

About Colestipol

What Is Colestipol Used For?

Brand name: Colestid

Colestipol — available as oral suspension and tablets under brands including Colestid, Flavored Colestid, and Colestipol Hydrochloride — is used as part of a broader treatment plan (including diet) to lower elevated LDL cholesterol in adults with primary hypercholesterolemia (a condition where LDL cholesterol stays high despite dietary changes).

It is not a standalone fix. Diet, weight management, and other lifestyle changes come first, and colestipol is added when those steps alone aren't enough to reach target LDL levels.

See full Colestipol drug information
Keep checking

Other Drugs & Quercetin

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

0Major
1,169Moderate
0Minor
1,660No known interaction
Moderate

1,169 interactions

Showing 60 of 1,169 moderate interactions — see all 1,169 on the Quercetin page.

No interaction 1,660 drugs checked — show the list

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

Showing the 60 most looked-up of 1,660 medications checked with no known interaction — see the full Quercetin list.

Evidence & sources

Quercetin References

The 26 references that drive our Quercetin 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. Shoskes DA, Zeitlin SI, Shahed A, Rajfer J. Quercetin in men with category III chronic prostatitis: A preliminary prospective, double-blind, placebo-controlled trial. Urol 1999;54:960-3. PubMed
  2. Starvic B. Quercetin in our diet: from potent mutagen to probable anticarcinogen. Clin Biochem 1994;27:245-8. PubMed
  3. Ferry DR, Smith A, Malkhandi J, et al. Phase I clinical trial of the flavonoid quercetin: Pharmacokinetics and evidence for in vivo tyrosine kinase inhibition. Clin Cancer Res 1996;2:659-67..
  4. Obach RS. Inhibition of human cytochrome P450 enzymes by constituents of St. John's wort, an herbal preparation used in the treatment of depression. J Pharmacol Exp Ther 2000;294:88-95. DOI
  5. Edwards RL, Lyon T, Litwin SE, et al. Quercetin reduces blood pressure in hypertensive subjects. J Nutr 2007;137:2405-11.
  6. Kim KA, Park PW, Kim HK, et al. Effect of quercetin on the pharmacokinetics of rosiglitazone, a CYP2C8 substrate, in healthy subjects. J Clin Pharmacol 2005;45:941-6. PubMed
  7. DiCenzo R, Frerichs V, Larppanichpoonphol P, et al. Effect of quercetin on the plasma and intracellular concentrations of saquinavir in healthy adults. Pharmacotherapy 2006;26:1255-61. PubMed
  8. Choi JS, Choi BC, Choi KE. Effect of quercetin on the pharmacokinetics of oral cyclosporine. Am J Health Syst Pharm 2004;61:2406-9. PubMed
  9. Choi JS, Jo BW, Kim YC. Enhanced paclitaxel bioavailability after oral administration of paclitaxel or prodrug to rats pretreated with quercetin. Eur J Pharm Biopharm 2004;57:313-8. PubMed
  10. Vaclavikova R, Horsky S, Simek P, Gut I. Paclitaxel metabolism in rat and human liver microsomes is inhibited by phenolic antioxidants. Naunyn Schmiedebergs Arch Pharmacol 2003;368:200-9. PubMed
  11. Di Bari L, Ripoli S, Pradhan S, Salvadori P. Interactions between quercetin and warfarin for albumin binding: A new eye on food/drug interference. Chirality 2010;22:593-6. PubMed
  12. Lamson, D. W. and Brignall, M. S. Antioxidants and cancer, part 3: quercetin. Altern.Med.Rev. 2000;5(3):196-208.
  13. Duan KM, Wang SY, Ouyang W, Mao YM, Yang LJ. Effect of quercetin on CYP3A activity in Chinese healthy participants. J Clin Pharmacol 2012;52(6):940-6. PubMed
  14. Wang SY, Duan KM, Li Y, et al. Effect of quercetin on P-glycoprotein transport ability in Chinese healthy subjects. Eur J Clin Nutr 2013;67(4):390-4. PubMed
  15. Nguyen MA, Staubach P, Wolffram S, Langguth P. Effect of single-dose and short-term administration of quercetin on the pharmacokinetics of talinolol in humans - Implications for the evaluation of transporter-mediated flavonoid-drug interactions. Eur J Pha 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 Quercetin and Colestipol Together: Common Questions

Is it safe to take Quercetin with Colestipol?
We do not list a known interaction between Quercetin and Colestipol. 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 Quercetin and Colestipol have any of the same side effects?
Yes — our sources link each of them separately to 4 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 Quercetin and Colestipol at the same time of day?
At least one FDA label for a product containing Colestipol 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 Colestipol on its own and move Quercetin 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.
Are Quercetin and Colestipol used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Quercetin in each. That is a conversation for your prescriber, especially if Colestipol is being adjusted to a target.
How was the Quercetin and Colestipol combination checked?
Interactions in our licensed database are recorded against drug classes. Colestipol is filed under 2 classifications, and Quercetin has documented interactions with 21 drug classes — none of Colestipol'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 Quercetin interact with any other medications?
Yes. Quercetin has 1,169 documented drug interactions in our database — Colestipol 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 Colestipol interact with any supplements?
Yes. Colestipol has documented interactions with 18 supplements in our database — Quercetin is not one of them. The Colestipol 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 Colestipol and Quercetin?

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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.