Gras + Tafenoquine
Tafenoquine brand names: Krintafel, Arakoda.
We found no known interaction between Gras and Tafenoquine 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 Tafenoquine states a food rule worth keeping to.
Gras and Tafenoquine
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 Tafenoquine and Gras 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 Gras at all — not against Tafenoquine, 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.
Gras safety at a glance
Safety guidance is general; always confirm with your pharmacist or doctor for your situation.
Some Tafenoquine Products Have a Food Rule — Gras Should Not Break It
At least one FDA label for a product containing Tafenoquine says to take it with food. If you take Gras on an empty stomach out of habit, keep them separate — and take Tafenoquine 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 Tafenoquine 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.
( 2.1 ) Regimen Name Timing Dosage Loading regimen For each of the 3 days before travel to a malarious area 200 mg (2 of the 100 mg tablets) once daily for 3 days Maintenance regimen While in the malarious area 200 mg (2 of the 100 mg tablets) once weekly – start 7 days after the last loading regimen dose Terminal prophylaxis regimen In the week following exit from the malarious area 200 mg (2 of
From the Dosage and Administration section of the FDA label we read for Tafenoquine — 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.
See Every Supplement That Interacts With Tafenoquine
This page covers Gras only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Tafenoquine page lists 17 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 · 7 moderate · 9 minor.
From our pharmacist’s overview on the Tafenoquine page
“Tafenoquine (Krintafel, Arakoda) protects against malaria, including the relapsing kind that hides in the liver, and every supplement known to interact with it threatens the same thing, how much of the pill actually reaches your blood. That deserves genuine care, since a partly absorbed antimalarial can let parasites survive and resurf…”
Reviewed by 2 · Jul 18, 2026
Where Gras and Tafenoquine 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.
#799 of 1,452 supplements looked up here in the last 7 days
#2,240 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. Gras is not yet covered by that licensed database, so its write-up cites publicly available medical sources directly (see the references below).
- Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Gras reference on this page ↓
- Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Gras and Tafenoquine records this page draws on were last updated June 20, 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 Gras
What is Gras?
We could not find reliable information about a dietary supplement or herb called "Gras." The name may be a misspelling, a brand name, or a local/regional term, so we cannot confirm what it is, what it does, or whether it is safe. Please double-check the name with your pharmacist or the product label before using it.
An interaction check asks whether these two react with each other — it does not ask whether Gras is a good idea for someone in your situation. Here is what our Gras record says about it on its own.
Gras: dosing
There is no established or recommended dose for "Gras" because the product cannot be reliably identified. We will not guess an amount. If you have a labeled product, follow the manufacturer's instructions only after confirming the actual ingredient with a pharmacist or doctor.
From our Gras monograph — the full record covers uses, side effects and every documented interaction.
About Tafenoquine
What Is Tafenoquine Used For?
Brand names: Krintafel, Arakoda
Tafenoquine is used for two distinct purposes depending on the product. Arakoda and Kodatef are used for malaria prophylaxis — that is, preventing malaria in adults 18 and older who are traveling to or living in areas where malaria is present.
Krintafel is used for the radical cure of Plasmodium vivax malaria — meaning it prevents the malaria parasite from coming back (relapsing) in patients 16 and older who are already being treated with chloroquine for an active P. vivax infection. Krintafel is not used to treat an active malaria attack on its own, and it should only be used alongside chloroquine, not other antimalarials.
Most-Reported Side Effects for Tafenoquine
From FAERS, the FDA’s public side-effect reporting system (70 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.
Other Drugs & Gras
Browse every other medication we’ve checked against Gras — 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 Gras against these medications and found no known interaction in our sources. Open any page to confirm.
- Apixaban ›
- Levothyroxine ›
- Amlodipine ›
- Methylphenidate ›
- Warfarin ›
- Sertraline ›
- Testosterone ›
- Ivermectin ›
- Losartan Potassium ›
- Abemaciclib ›
- Aspirin ›
- 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 ›
- Bendamustine ›
- Methotrexate ›
- 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 Gras list.
Gras References
The 3 sources that drive our Gras monograph — publicly available pages from reputable medical and government organizations. Every link was verified to work before publishing. Gras is not covered by the licensed Natural Medicines interaction database, so its page cites these public sources directly.
- Dietary and Herbal Supplements — NIH NCCIH Source
- Herbs and Supplements — MedlinePlus Source
- Generally Recognized as Safe (GRAS) — U.S. Food and Drug Administration Source
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 Gras and Tafenoquine Together: Common Questions
Is it safe to take Gras with Tafenoquine?
Should I take Gras and Tafenoquine at the same time of day?
Does Tafenoquine interact with any supplements?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Keep Exploring
Still Have a Question About Tafenoquine and Gras?
Our pharmacists answer your medication & supplement questions — free.
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.