Drug & supplement interaction

Collard + Hydroxychloroquine

Hydroxychloroquine brand name: Plaquenil.

No Known Interaction
Medically reviewed by · Updated June 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Collard and Hydroxychloroquine 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 Hydroxychloroquine states a food rule worth keeping to.

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Interaction report

Collard and Hydroxychloroquine

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 Hydroxychloroquine and Collard 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.

Collard safety at a glance

Collard overall Generally safe Collard is widely eaten as a food and is generally safe for most people.
Pregnancy Generally safe Normal food amounts are considered safe and nutritious during pregnancy.
Breastfeeding Generally safe Eating collard as a food is generally considered safe while breastfeeding.

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

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

Why No Interaction Is Listed for Hydroxychloroquine

Interactions in our licensed database are recorded against drug classes, not just single drug names. Hydroxychloroquine is filed under 3 classifications — cytochrome p450 2d6 (cyp2d6) inhibitors, qt interval-prolonging drugs, oral drugs. Collard has documented interactions with 1 drug class — the most serious being antidiabetes drugs (moderate) — and none of Hydroxychloroquine’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

Collard Does Interact With Other Medications

Collard has 86 moderate known drug interactions in our database — Hydroxychloroquine isn’t one of them. If you take anything else, check it against the full list below.

Moderate 86 No known interaction 2,744 (incl. Hydroxychloroquine)
Taking anything else?

Check Another of Your Medications Against Collard

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

What to actually watch for

What Hydroxychloroquine’s Own FDA Label Lists

This is not an interaction — none of it involves Collard. These are the most notable effects listed in the ADVERSE REACTIONS section of Hydroxychloroquine’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both. 10 of them are worth acting on rather than waiting out — marked below.

  • Mania or an unusually elevated mood Worth acting on
  • Thoughts of self-harm Worth acting on
  • Hearing loss Worth acting on
  • Muscle weakness Worth acting on
  • Unsteadiness Worth acting on
  • Low blood sugar Worth acting on
  • Hallucinations Worth acting on
  • Heart failure Worth acting on
  • Wheezing Worth acting on
  • An irregular heartbeat Worth acting on

Showing the 10 most notable of 43 label-listed effects — ranked by how unusual each one is across medicines generally, with serious effects weighted up.

From the ADVERSE REACTIONS section of the FDA label for Hydroxychloroquine. Read the label on DailyMed › Collard’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Collard side to compare — that is a limit of the record, not a statement that Collard has no side effects.

How to take them

Some Hydroxychloroquine Products Have a Food Rule — Collard Should Not Break It

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

Rheumatoid Arthritis in Adults ( 2.3 ): Initial dosage: 400 mg to 600 mg daily Chronic dosage: 200 mg once daily or 400 mg once daily (or in two divided doses) Systemic Lupus Erythematosus in Adults ( 2.4 ): 200 mg once daily or 400 mg once daily (or in two divided doses) Chronic Discoid Lupus Erythematosus in Adults ( 2.5 ): 200 mg once daily or 400 mg once daily (or in two divided doses) 2.1 Imp

From the Dosage and Administration section of the FDA label we read for Hydroxychloroquine — 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 Collard or Hydroxychloroquine

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

This page covers Collard only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Hydroxychloroquine page lists 32 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Cesium (major) and Ephedra (major).

By severity: 7 major · 16 moderate · 9 minor.

From our pharmacist’s overview on the Hydroxychloroquine page

“Hydroxychloroquine (Plaquenil) can stretch the QT interval on its own, the pause between heartbeats that, prolonged too far, can trigger a dangerous rhythm. Thirteen of the supplements and herbs on this page add to that same effect, grapefruit in large amounts among them, and that overlap is why this list calls for genuine care rather…”

Reviewed by 2 · Jul 18, 2026

Open the Hydroxychloroquine interaction page

One more smart check

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

We hold 379 real supplement products containing Collard, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Collard. Even though Collard itself has no known interaction with Hydroxychloroquine, 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 Collard and Hydroxychloroquine 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 Collard
Top half

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

29 days ago today
Medication Hydroxychloroquine
Top 25%

#694 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 Collard reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Collard and Hydroxychloroquine records this page draws on were last updated June 22, 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 Collard

What is Collard?

  • General nutrition and vitamin source
  • Bone health
  • Heart health support
  • Digestive fiber
  • Antioxidant intake

Collard is a leafy green vegetable in the cabbage family that is rich in vitamins, minerals, and fiber, and is best thought of as a nutritious food rather than a medicine. Eating it as part of a balanced diet is healthy for most people, but there is little high-quality research on collard as a concentrated supplement. If you take blood thinners or have kidney concerns, talk with your pharmacist or doctor because of its vitamin K and oxalate content.

Brassica oleracea var. viridis · Brassicaceae · Leaves · Fresh or cooked leaves, frozen greens; occasionally powders or capsules

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

Collard: dosing

There is no established medicinal dose for collard. As a food, it can be enjoyed in normal serving sizes as part of a varied diet, just like other vegetables.If you choose a collard powder or capsule, there is no standardized dose, so follow the directions on the product label.

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

Read the full Collard monograph & all interactions
Medication

About Hydroxychloroquine

What Is Hydroxychloroquine Used For?

Brand name: Plaquenil

Hydroxychloroquine tablets are used to treat uncomplicated malaria and to help prevent malaria in areas where the parasite has not developed resistance to it — in both adults and children. It is also used in adults to treat rheumatoid arthritis, systemic lupus erythematosus (SLE), and chronic discoid lupus erythematosus.

There are important limits: it is not recommended for complicated or drug-resistant malaria, malaria acquired in regions where resistance is known, or to prevent malaria relapses caused by P. vivax or P. ovale. Its use for the autoimmune conditions (rheumatoid arthritis and lupus) is approved for adults only.

See full Hydroxychloroquine drug information
Keep checking

Other Drugs & Collard

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

0Major
86Moderate
0Minor
2,743No known interaction
86 Moderate 2,743 No interaction
Moderate

86 interactions

Showing 60 of 86 moderate interactions — see all 86 on the Collard page.

No interaction 2,743 drugs checked — show the list

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

Showing the 60 most looked-up of 2,743 medications checked with no known interaction — see the full Collard list.

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

Collard References

The 4 references that drive our Collard 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. Zhao H, Lin J, Grossman HB, et al. Dietary isothiocyanates, GSTM1, GSTT1, NAT2 polymorphisms and bladder cancer risk. Int J Cancer 2007;120:2208-13.
  2. Cohen, J. H., Kristal, A. R., and Stanford, J. L. Fruit and vegetable intakes and prostate cancer risk. J Natl.Cancer Inst. 1-5-2000;92(1):61-68. PubMed
  3. Gaudet MM, Britton JA, Kabat GC, et al. Fruits, vegetables, and micronutrients in relation to breast cancer modified by menopause and hormone receptor status. Cancer Epidemiol Biomarkers Prev 2004;13(9):1485-94. DOI
  4. Amssayef A, Eddouks M. Antihyperglycemic Effect of the Moroccan Collard Green (Brassica oleracea var. viridis) in Streptozotocin-Induced Diabetic Rats. Endocr Metab Immune Disord Drug Targets 2020. 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 Collard and Hydroxychloroquine Together: Common Questions

Is it safe to take Collard with Hydroxychloroquine?
We do not list a known interaction between Collard and Hydroxychloroquine. 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.
Should I take Collard and Hydroxychloroquine at the same time of day?
At least one FDA label for a product containing Hydroxychloroquine says to take it with food. If you take Collard on an empty stomach out of habit, keep them separate and take Hydroxychloroquine with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Hydroxychloroquine products can differ — so check the directions on your own box. This is about absorption, not an interaction.
How was the Collard and Hydroxychloroquine combination checked?
Interactions in our licensed database are recorded against drug classes. Hydroxychloroquine is filed under 3 classifications, and Collard has documented interactions with 1 drug class — none of Hydroxychloroquine'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 Collard interact with any other medications?
Yes. Collard has 86 documented drug interactions in our database — Hydroxychloroquine 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 Hydroxychloroquine interact with any supplements?
Yes. Hydroxychloroquine has documented interactions with 32 supplements in our database — Collard is not one of them. The Hydroxychloroquine 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

Collard monograph Uses, safety profile, and every drug interaction in one place Hydroxychloroquine drug information The full plain-English guide to this medication Hydroxychloroquine supplement interactions Every supplement checked against Hydroxychloroquine, 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 4 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Hydroxychloroquine and Collard?

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.