Timothy Grass + Hydroxychloroquine
Hydroxychloroquine brand name: Plaquenil.
We found no known interaction between Timothy Grass 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, 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.
Timothy Grass 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 Timothy Grass 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 Timothy Grass at all — not against Hydroxychloroquine, 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.
Timothy Grass safety at a glance
Safety guidance is general; always confirm with your pharmacist or doctor for your situation.
Some Hydroxychloroquine Products Have a Food Rule — Timothy Grass Should Not Break It
At least one FDA label for a product containing Hydroxychloroquine says to take it with food. If you take Timothy Grass 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.
Questions About Timothy Grass 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 Timothy Grass 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.
See Every Supplement That Interacts With Hydroxychloroquine
This page covers Timothy Grass 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
Where Timothy Grass 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.
#1,071 of 1,452 supplements looked up here in the last 7 days
#260 of 2,830 medications looked up here in the last 7 days
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 Timothy Grass reference on this page ↓
- Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Timothy Grass and Hydroxychloroquine 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.
About Timothy Grass
What is Timothy Grass?
- Grass pollen allergy (hay fever)
- Allergic rhinitis
- Allergic conjunctivitis (itchy, watery eyes)
- Allergy desensitization (immunotherapy)
- Allergy testing
Timothy grass is a common grass whose pollen is a major cause of seasonal hay fever. In medicine, a purified, standardized form of its pollen is used in prescription allergy immunotherapy tablets and shots to gradually reduce allergic reactions. It is not a typical dietary supplement, and any product containing timothy grass allergen should be used only under medical supervision.
Phleum pratense · Poaceae · Pollen (used to make allergy extracts and immunotherapy products) · Sublingual immunotherapy tablets, allergen extracts for allergy testing and allergy shots
An interaction check asks whether these two react with each other — it does not ask whether Timothy Grass is a good idea for someone in your situation. Here is what our Timothy Grass record says about it on its own.
Timothy Grass: dosing
There is no general supplement dose for timothy grass. The amount of allergen in immunotherapy products is carefully standardized by the manufacturer, and the right product and schedule depend on the individual.Sublingual tablets are usually taken once daily, often started before grass pollen season and continued as directed. Allergy shots follow a build-up and then maintenance schedule set by an allergist.Because dosing is specific and reactions are possible, you should only use timothy grass allergen products exactly as prescribed.
From our Timothy Grass monograph — the full record covers uses, side effects and every documented interaction.
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.
Other Drugs & Timothy Grass
Browse every other medication we’ve checked against Timothy Grass — both the ones with a known interaction and the ones without. Select any drug for the full detail.
No drugs match “”.
No interaction 2,829 drugs checked — show the list
We also checked Timothy Grass against these medications and found no known interaction in our sources. Open any page to confirm.
- Apixaban ›
- Levothyroxine ›
- Amlodipine ›
- Warfarin ›
- Methylphenidate ›
- Sertraline ›
- Testosterone ›
- Ivermectin ›
- Losartan Potassium ›
- Aspirin ›
- Abemaciclib ›
- Acetaminophen ›
- Metoprolol ›
- Rosuvastatin ›
- Rivaroxaban ›
- Escitalopram ›
- Clopidogrel ›
- Atorvastatin ›
- Docusate ›
- Tadalafil ›
- Tirzepatide ›
- Methamphetamine ›
- Ibuprofen ›
- Warfarin Sodium ›
- Valacyclovir ›
- Hydroxyurea ›
- Sumatriptan ›
- Semaglutide ›
- Prednisone ›
- Propranolol ›
- Lisdexamfetamine ›
- Amitriptyline ›
- Metformin ›
- Amoxicillin ›
- Lisinopril ›
- Isotretinoin ›
- Amlodipine Besylate ›
- Methotrexate ›
- Bendamustine ›
- Bupropion ›
- Amphetamine ›
- Fluoxetine ›
- Doxycycline ›
- Azithromycin ›
- Acyclovir ›
- Pregabalin ›
- Lamotrigine ›
- Dextroamphetamine ›
- Gabapentin ›
- Acetaminophen, Codeine ›
- Levothyroxine, Liothyronine ›
- Clonazepam ›
- Quetiapine ›
- Naproxen ›
- Omeprazole ›
- Letrozole ›
- Duloxetine ›
- Methylene Blue ›
- Buspirone ›
- Citalopram ›
Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Timothy Grass list.
Timothy Grass References
The 10 references that drive our Timothy Grass 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.
- Dahl R, Stender A, Rak S. Specific immunotherapy with SQ standardized grass allergen tablets in asthmatics with rhinoconjunctivitis. Allergy 2006;61:185-90. PubMed
- Casanovas M, Sastre J, Fernández-Nieto M, et al. Double-blind study of tolerability and antibody production of unmodified and chemically modified allergen vaccines of Phleum pratense. Clin Exp Allergy 2005;35:1377-83.
- Roberts G, Hurley C, Turcanu V, Lack G. Grass pollen immunotherapy as an effective therapy for childhood seasonal allergic asthma. J Allergy Clin Immunol 2006;117:263-8. PubMed
- Malling HJ, Lund L, Ipsen H, Poulsen L. Safety and immunological changes during sublingual immunotherapy with standardized quality grass allergen tablets. J Investig Allergol Clin Immunol 2006;16:162-8.
- Calderon M, Essendrop M. Specific immunotherapy with high dose SO standardized grass allergen tablets was safe and well tolerated. J Investig Allergol Clin Immunol 2006;16:338-44.
- Rak S, Yang WH, Pedersen MR, Durham SR. Once-daily sublingual allergen-specific immunotherapy improves quality of life in patients with grass pollen-induced allergic rhinoconjunctivitis: a double-blind, randomised study. Qual Life Res 2007;16:191-201. PubMed
- Rossi RE, Monasterolo G, Coco G, et al. Evaluation of serum IgG4 antibodies specific to grass pollen allergen components in the follow up of allergic patients undergoing subcutaneous and sublingual immunotherapy. Vaccine 2007;25:957-64. PubMed
- Sola J, da Silva Ferreira JA, Dionicio Elera J, et al. Timothy grass pollen therapeutic vaccine: optimal dose for subcutaneous immunotherapy. Immunotherapy. 2016;8(3):251-63. PubMed
- Sola J, Sánchez V, Landeta A, Madariaga B, Martínez A, Álvarez-Cuesta E. A Phase I clinical trial with subcutaneous immunotherapy vaccine of Timothy grass pollen extract according to EMA guidelines. Immunotherapy. 2015;7(4):343-52. PubMed
- Maloney J, Bernstein DI, Nelson H, et al. Efficacy and safety of grass sublingual immunotherapy tablet, MK-7243: a large, randomized controlled trial. Ann Allergy Asthma Immunol. 2014 Feb;112(2):146-153.e2. 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.
Taking Timothy Grass and Hydroxychloroquine Together: Common Questions
Is it safe to take Timothy Grass with Hydroxychloroquine?
Do Timothy Grass and Hydroxychloroquine have any of the same side effects?
Should I take Timothy Grass and Hydroxychloroquine at the same time of day?
Does Hydroxychloroquine interact with any supplements?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
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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.