Mercury Herb + Mefloquine
Mefloquine brand name: Lariam.
We found no known interaction between Mercury Herb and Mefloquine 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 Mefloquine 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.
Mercury Herb and Mefloquine
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 Mefloquine and Mercury Herb 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 Mercury Herb at all — not against Mefloquine, 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.
Mercury Herb safety at a glance
Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.
Mercury Herb in Pregnancy & Breastfeeding
When used orally; avoid using.
DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center
Some Mefloquine Products Have a Food Rule — Mercury Herb Should Not Break It
At least one FDA label for a product containing Mefloquine says to take it on an empty stomach. Most supplements — Mercury Herb included — are taken with a meal, so the easy mistake is swallowing both together at breakfast. Where that rule applies, keep Mefloquine on its own and move Mercury Herb 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 Mefloquine 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.
The drug should not be taken on an empty stomach and should be administered with at least 8 oz (240 mL) of water.
From the Dosage and Administration section of the FDA label we read for Mefloquine — 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 Mefloquine
This page covers Mercury Herb only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Mefloquine page lists 23 supplements it has a documented interaction with, worst first, each one explained.
The most serious there right now: Activated Charcoal (major), Biofeedback (moderate), Coffee Charcoal (moderate), Dendrobium (moderate) and European Mandrake (moderate).
By severity: 1 major · 13 moderate · 9 minor.
From our pharmacist’s overview on the Mefloquine page
“Mefloquine (Lariam) prevents and treats malaria and carries its own well-known warnings about seizures and psychiatric effects, so I take this interaction list more seriously than most. Six of the 23 supplements on file, including ginkgo and melatonin, may lower the seizure threshold, a poor match for a drug with mefloquine's neurologi…”
Reviewed by 2 · Jul 18, 2026
Where Mercury Herb and Mefloquine 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.
#1,331 of 1,452 supplements looked up here in the last 7 days
#2,419 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 Mercury Herb reference on this page ↓
- Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Mercury Herb and Mefloquine 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 Mercury Herb
What is Mercury Herb?
- Constipation
- Mild skin irritation
- Swelling or inflammation (topical)
- Traditional folk remedy
Mercury Herb (Mercurialis annua) is a traditional European plant once used as a mild laxative and topical remedy, but it has very little modern scientific support and is considered potentially toxic. Because the plant can cause serious poisoning when misused, most herbal experts no longer recommend it, and you should talk to a pharmacist or doctor before considering it.
Mercurialis annua · Euphorbiaceae · Leaves and aerial (above-ground) parts · Dried herb, tea/infusion, poultice, traditional topical preparations
An interaction check asks whether these two react with each other — it does not ask whether Mercury Herb is a good idea for someone in your situation. Here is what our Mercury Herb record says about it on its own.
Mercury Herb: dosing
There is no established or standardized safe dose for Mercury Herb. Because of its toxicity concerns and the lack of modern research, no reliable amount can be recommended.We do not provide specific dosing for this plant. In most cases, safer and better-studied options are available for constipation and skin concerns.
From our Mercury Herb monograph — the full record covers uses, side effects and every documented interaction.
About Mefloquine
What Is Mefloquine Used For?
Brand name: Lariam
Mefloquine Hydrochloride tablets are used to treat mild to moderate acute malaria caused by Plasmodium falciparum (including strains resistant to chloroquine) and Plasmodium vivax. They are also used to prevent malaria infections, including chloroquine-resistant strains of P. falciparum, in people traveling to malaria-endemic areas.
Important note: mefloquine does not eliminate the liver stage of P. vivax, so patients treated for P. vivax malaria usually need an additional medication (such as primaquine) afterward to prevent relapse.
Other Drugs & Mercury Herb
Browse every other medication we’ve checked against Mercury Herb — 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 Mercury Herb against these medications and found no known interaction in our sources. Open any page to confirm.
- Apixaban ›
- Levothyroxine ›
- Amlodipine ›
- Warfarin ›
- Methylphenidate ›
- Sertraline ›
- Abemaciclib ›
- Ivermectin ›
- Testosterone ›
- Acetaminophen ›
- Losartan Potassium ›
- Aspirin ›
- Rosuvastatin ›
- Metoprolol ›
- Clopidogrel ›
- Escitalopram ›
- Rivaroxaban ›
- Atorvastatin ›
- Docusate ›
- Tirzepatide ›
- Ibuprofen ›
- Methamphetamine ›
- Warfarin Sodium ›
- Tadalafil ›
- Valacyclovir ›
- Hydroxyurea ›
- Sumatriptan ›
- Semaglutide ›
- Prednisone ›
- Amitriptyline ›
- Propranolol ›
- Metformin ›
- Lisdexamfetamine ›
- Isotretinoin ›
- Amoxicillin ›
- Methotrexate ›
- Lisinopril ›
- Amlodipine Besylate ›
- Amphetamine ›
- Bendamustine ›
- Bupropion ›
- Fluoxetine ›
- Doxycycline ›
- Azithromycin ›
- Pregabalin ›
- Acyclovir ›
- Lamotrigine ›
- Dextroamphetamine ›
- Gabapentin ›
- Levothyroxine, Liothyronine ›
- Acetaminophen, Codeine ›
- Naproxen ›
- Clonazepam ›
- Quetiapine ›
- Omeprazole ›
- Duloxetine ›
- Letrozole ›
- Methylene Blue ›
- Citalopram ›
- Buspirone ›
Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Mercury Herb list.
Mercury Herb References
The 3 references that drive our Mercury Herb 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.
- Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
- Vallverdu A, Garcia-Ortega P, Martinez J, et al. Mercurialis annua: characterization of main allergens and cross- reactivity with other species. Int Arch Allergy Immunol 1997;112:356-64. PubMed
- Garcia-Ortega P, Martinez J, Martinez A, et al. Mercurialis annua pollen: a new source of allergic sensitization and respiratory disease. J Allergy Clin Immunol 1992;89:987-93.
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 Mercury Herb and Mefloquine Together: Common Questions
Is it safe to take Mercury Herb with Mefloquine?
Do Mercury Herb and Mefloquine have any of the same side effects?
Should I take Mercury Herb and Mefloquine at the same time of day?
Does Mefloquine 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.