Myrcia + Lapatinib
Lapatinib brand name: Tykerb.
We found no known interaction between Myrcia and Lapatinib 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.
Myrcia and Lapatinib
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 Lapatinib and Myrcia 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.
Myrcia safety at a glance
Safety guidance is general; always confirm with your pharmacist or doctor for your situation.
Why No Interaction Is Listed for Lapatinib
Interactions in our licensed database are recorded against drug classes, not just single drug names. Lapatinib is filed under 3 classifications — cytochrome p450 3a4 (cyp3a4) inhibitors, cytochrome p450 3a4 (cyp3a4) substrates, oral drugs. Myrcia has documented interactions with 1 drug class — the most serious being levothyroxine (synthroid, others) (moderate) — and none of Lapatinib’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.
Myrcia Does Interact With Other Medications
Myrcia has 3 moderate known drug interactions in our database — Lapatinib isn’t one of them. If you take anything else, check it against the full list below.
Check Another of Your Medications Against Myrcia
We haven’t checked that one against Myrcia yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Myrcia. Pick one to open its full report.
See Every Supplement That Interacts With Lapatinib
This page covers Myrcia only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Lapatinib page lists 143 supplements it has a documented interaction with, worst first, each one explained.
The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).
By severity: 3 major · 100 moderate · 40 minor.
From our pharmacist’s overview on the Lapatinib page
“Of the 143 supplements on file for lapatinib (Tykerb), nearly all press on the same point, the CYP3A4 enzyme that clears this HER2-targeted breast cancer drug. That deserves real caution, since lapatinib only works when its blood level stays in range.”
Reviewed by 2 · Jul 18, 2026
Where Myrcia and Lapatinib 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.
#1,116 of 1,452 supplements looked up here in the last 7 days
#2,248 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 Myrcia reference on this page ↓
- Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Myrcia and Lapatinib 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.
About Myrcia
What is Myrcia?
- Blood sugar support
- Digestive upset and diarrhea
- Mild urinary complaints
- Astringent for the gut
- Traditional 'pedra-hume-caa' folk remedy
Myrcia is a group of tropical shrubs and trees in the myrtle family, used in South American folk medicine—often as a tea—mainly for blood sugar and digestive complaints. Human evidence is very limited, so it should not replace proven treatments. Talk with your pharmacist or doctor before using it, especially if you have diabetes or take other medicines.
Myrtaceae · Leaves (and sometimes bark) · Tea, dried leaf, capsules, liquid extracts
An interaction check asks whether these two react with each other — it does not ask whether Myrcia is a good idea for someone in your situation. Here is what our Myrcia record says about it on its own.
Myrcia: dosing
There is no established standardized dose for Myrcia. Traditional use is usually as a tea made from the dried leaves, but amounts vary widely and are not backed by clinical research.If you choose to try a commercial product, follow the directions on the label and do not exceed them.
From our Myrcia monograph — the full record covers uses, side effects and every documented interaction.
About Lapatinib
What Is Lapatinib Used For?
Brand name: Tykerb
Lapatinib tablets — sold under the brand name Tykerb — are used to treat advanced or metastatic breast cancer in patients whose tumors overexpress the HER2 protein. They are always used in combination with another medicine, not alone.
Tykerb is approved in combination with capecitabine for HER2-positive advanced or metastatic breast cancer in patients who have already received prior treatment including an anthracycline, a taxane, and trastuzumab, and whose disease has progressed on trastuzumab. Tykerb is also approved in combination with letrozole for postmenopausal women with hormone receptor-positive, HER2-positive metastatic breast cancer when hormonal therapy is appropriate.
Most-Reported Side Effects for Lapatinib
From FAERS, the FDA’s public side-effect reporting system (15,427 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.
Other Drugs & Myrcia
Browse every other medication we’ve checked against Myrcia — both the ones with a known interaction and the ones without. Select any drug for the full detail.
No drugs match “”.
3 interactions
No interaction 2,826 drugs checked — show the list
We also checked Myrcia against these medications and found no known interaction in our sources. Open any page to confirm.
- Apixaban ›
- Amlodipine ›
- Methylphenidate ›
- Warfarin ›
- Sertraline ›
- Losartan Potassium ›
- Testosterone ›
- Ivermectin ›
- Abemaciclib ›
- Aspirin ›
- Metoprolol ›
- Acetaminophen ›
- Rosuvastatin ›
- Rivaroxaban ›
- Escitalopram ›
- Clopidogrel ›
- Atorvastatin ›
- Tadalafil ›
- Docusate ›
- Tirzepatide ›
- Ibuprofen ›
- Methamphetamine ›
- Hydroxyurea ›
- Warfarin Sodium ›
- Valacyclovir ›
- Sumatriptan ›
- Semaglutide ›
- Prednisone ›
- Lisdexamfetamine ›
- Propranolol ›
- Metformin ›
- Amitriptyline ›
- Amoxicillin ›
- Lisinopril ›
- Isotretinoin ›
- Methotrexate ›
- Amlodipine Besylate ›
- Bendamustine ›
- Bupropion ›
- Amphetamine ›
- Fluoxetine ›
- Doxycycline ›
- Acyclovir ›
- Azithromycin ›
- Lamotrigine ›
- Pregabalin ›
- Dextroamphetamine ›
- Gabapentin ›
- Acetaminophen, Codeine ›
- Quetiapine ›
- Clonazepam ›
- Naproxen ›
- Omeprazole ›
- Letrozole ›
- Methylene Blue ›
- Duloxetine ›
- Buspirone ›
- Citalopram ›
- Ciprofloxacin ›
- Bisoprolol ›
Showing the 60 most looked-up of 2,826 medications checked with no known interaction — see the full Myrcia list.
Myrcia References
The 2 references that drive our Myrcia 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.
- Russo EM, Reichelt AA, De Sa JR, et al. Clinical trial of Myrcia uniflora and Bauhinia forficata leaf extracts in normal and diabetic patients. Braz J Med Biol Res 1990;23(1):11-20.
- Ferreira AC, Neto JC, da Silva AC, et al. Inhibition of thyroid peroxidase by Myrcia uniflora flavonoids. Chem Res Toxicol 2006;19(3):351-55.
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 Myrcia and Lapatinib Together: Common Questions
Is it safe to take Myrcia with Lapatinib?
How was the Myrcia and Lapatinib combination checked?
Does Myrcia interact with any other medications?
Does Lapatinib interact with any supplements?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Keep Exploring
Still Have a Question About Lapatinib and Myrcia?
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.