Drug & supplement interaction

Gentian + Pemetrexed

Pemetrexed brand names: Alimta, Pemfexy.

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

We found no known interaction between Gentian and Pemetrexed 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 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.

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Interaction report

Gentian and Pemetrexed

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 Pemetrexed and Gentian 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.

Gentian safety at a glance

Gentian overall Use caution Generally tolerated in small amounts by healthy adults, but it can upset the stomach and is not well studied at high doses.
Pregnancy Avoid Not enough safety data, and traditional cautions exist, so it is best avoided during pregnancy.
Breastfeeding Avoid There is not enough reliable safety information, so avoid use while breastfeeding.

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

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

Why No Interaction Is Listed for Pemetrexed

Interactions in our licensed database are recorded against drug classes, not just single drug names. Pemetrexed is filed under a single classification — organic anion transporter 3 (oat3) substrates. Gentian has documented interactions with 1 drug class — the most serious being antihypertensive drugs (moderate) — and none of Pemetrexed’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

Gentian Does Interact With Other Medications

Gentian has 172 moderate known drug interactions in our database — Pemetrexed isn’t one of them. If you take anything else, check it against the full list below.

Moderate 172 No known interaction 2,658 (incl. Pemetrexed)
Taking anything else?

Check Another of Your Medications Against Gentian

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

What to actually watch for

No Interaction Found — But Data Suggests Gentian and Pemetrexed May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Reduced appetite / Diarrhea / Vomiting / Nausea Additional detail

    Gentian

    “Orally, gentian root, in combination with other herbs, has been reported to cause gastrointestinal adverse effects. Gastrointestinal intolerance occurred in patients with cancer-associated anorexia who took gentian tincture 1 mL three times daily, in conjunction with turmeric 1 gram and ginger 1 gram twice daily, for 14 days.”

    Gentian · Natural Medicines adverse-effect record, reported in anorexia.

    3 sources cited
    1. 374. Neubauer N, Marz RW. Placebo-controlled, randomized, double-blind, clincal trial with Sinupret sugar coated tablets on the basis of a therapy with antibiotics and decongestant nasal drops in acute sinusitis. Phytomedicine 1994;1:177-81.
    2. 379. Marz RW, Ismail C, Popp MA. Action profile and efficacy of a herbal combination preparation for the treatment of sinusitis. Wien Med Wochenschr 1999;149:202-8.
    3. 96263. Sanatani M, Younus J, Stitt L, et al. Tolerability of the combination of ginger (Zingiber officinalis), gentian (Gentiana lutea) and turmeric (Curcuma longa) in patients with cancer-associated anorexia. J Complement Integr Med. 2015;12(1):57-60.

    Pemetrexed

    Listed in the ADVERSE REACTIONS section of the FDA label for Pemetrexed. Read the label on DailyMed ›

Reported for Gentian but not commonly for Pemetrexed: bloating or gas.

Effects for Pemetrexed come from the ADVERSE REACTIONS section of its FDA label; effects for Gentian come from the Natural Medicines adverse-effect record, quoted above. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Overlapping uses

What Pemetrexed Is Prescribed For, and What Gentian Has Been Studied For

These two come up together because they touch the same health topic — not because they do the same job. Pemetrexed is a prescription medicine with approved uses on its FDA label. Gentian is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.

Pemetrexed is prescribed for: Pemetrexed Injection is used for non-squamous non-small cell lung cancer (NSCLC) in several situations: as an initial treatment (combined with pembrolizumab and platinum chemotherapy, or with cisplatin alone), as a maintenance treatment after platinum-based chemotherapy, or as a single agent when the cancer has come back after prior chemotherapy. It is not used for squamous cell non-small cell lung cancer. Pemetrexed Injection is also used, in combination with cisplatin, for the initial treatment of malignant pleural mesothelioma — a cancer of the lining of the lungs — in patients whose disease cannot be surgically removed or who are not good candidates for surgery.

Gentian has been studied for:

  • Cancer studied, not established Gentian has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows

    Gentian for cancer

    Although there has been interest in using topical gentian for cancer, there is insufficient reliable information about the clinical effects of gentian for this purpose.

Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Pemetrexed on your own; if you are taking Gentian for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.

Everything else you take

See Every Supplement That Interacts With Pemetrexed

This page covers Gentian only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Pemetrexed page lists 4 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: African Wild Potato (moderate), Banderol (moderate), Caffeic Acid (moderate) and Quercetin (moderate).

By severity: 4 moderate.

From our pharmacist’s overview on the Pemetrexed page

“Every supplement on file for pemetrexed (Alimta, Pemfexy) works the same way. Each can slow how the kidneys pull the drug out of the blood, which would let it linger and build to higher levels than intended.”

Reviewed by 2 · Jul 18, 2026

Open the Pemetrexed interaction page

One more smart check

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

We hold 749 real supplement products containing Gentian, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Gentian. Even though Gentian itself has no known interaction with Pemetrexed, 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 Gentian and Pemetrexed 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 Gentian
Top 25%

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

29 days ago today
Medication Pemetrexed
Top half

#711 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 Gentian reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Gentian and Pemetrexed 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.
Data structure & sourcing designed and verified by .
Supplement

About Gentian

What is Gentian?

  • Loss of appetite
  • Indigestion and bloating
  • Digestive bitter tonic
  • Stomach upset
  • Sluggish digestion

Gentian is a very bitter root traditionally used to stimulate appetite and ease mild digestive complaints, often as part of "bitters" before meals. The evidence is mostly traditional and preliminary, and while short-term use of normal amounts appears generally well tolerated in healthy adults, anyone with ulcers, reflux, or who is pregnant should be cautious and check with a pharmacist or doctor first.

Gentiana lutea · Gentianaceae · Root and rhizome · Tinctures, liquid extracts, teas, bitters, capsules, dried root

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

Gentian: dosing

There is no official, standardized dose for gentian, and products vary widely in strength. Traditional use involves small amounts of a tincture, extract, or tea taken shortly before meals.Because formulations differ, the safest approach is to follow the directions on the product label and not exceed the suggested amount. A pharmacist can help you choose a reasonable product and dose, and can review it against your other medicines and health conditions.

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

Read the full Gentian monograph & all interactions
Medication

About Pemetrexed Injection

What Is Pemetrexed Injection Used For?

Brand names: Alimta, Pemfexy

Pemetrexed Injection is used for non-squamous non-small cell lung cancer (NSCLC) in several situations: as an initial treatment (combined with pembrolizumab and platinum chemotherapy, or with cisplatin alone), as a maintenance treatment after platinum-based chemotherapy, or as a single agent when the cancer has come back after prior chemotherapy. It is not used for squamous cell non-small cell lung cancer.

Pemetrexed Injection is also used, in combination with cisplatin, for the initial treatment of malignant pleural mesothelioma — a cancer of the lining of the lungs — in patients whose disease cannot be surgically removed or who are not good candidates for surgery.

Most-Reported Side Effects for Pemetrexed

From FAERS, the FDA’s public side-effect reporting system (37,889 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Malignant neoplasm progression 3,095 reports
Anemia 2,134 reports
Nausea 1,906 reports
Diarrhea 1,824 reports
Pancytopenia 1,773 reports
See full Pemetrexed Injection drug information
Keep checking

Other Drugs & Gentian

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

0Major
172Moderate
0Minor
2,657No known interaction
172 Moderate 2,657 No interaction
Moderate

172 interactions

Showing 60 of 172 moderate interactions — see all 172 on the Gentian page.

No interaction 2,657 drugs checked — show the list

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

Showing the 60 most looked-up of 2,657 medications checked with no known interaction — see the full Gentian list.

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

Gentian References

The 5 references that drive our Gentian 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. Neubauer N, Marz RW. Placebo-controlled, randomized, double-blind, clincal trial with Sinupret sugar coated tablets on the basis of a therapy with antibiotics and decongestant nasal drops in acute sinusitis. Phytomedicine 1994;1:177-81.
  2. Marz RW, Ismail C, Popp MA. Action profile and efficacy of a herbal combination preparation for the treatment of sinusitis. Wien Med Wochenschr 1999;149:202-8.
  3. Uncini Manganelli RE, Chericoni S, Baragatti B. Ethnopharmacobotany in Tuscany: plants used as antihypertensives. Fitoterapia 2000;71:S95-100. PubMed
  4. Baragatti B, Calderone V, Testai L, et al. Vasodilator activity of crude methanolic extract of Gentiana kokiana Perr. et Song. (Gentianaceae). J Ethnopharmacol 2002;79:369-72. PubMed
  5. Sanatani M, Younus J, Stitt L, et al. Tolerability of the combination of ginger (Zingiber officinalis), gentian (Gentiana lutea) and turmeric (Curcuma longa) in patients with cancer-associated anorexia. J Complement Integr Med. 2015;12(1):57-60.

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 Gentian and Pemetrexed Together: Common Questions

Is it safe to take Gentian with Pemetrexed?
We do not list a known interaction between Gentian and Pemetrexed. 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.
Do Gentian and Pemetrexed have any of the same side effects?
Yes — our sources link each of them separately to 4 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Are Gentian and Pemetrexed used for the same thing?
They overlap in purpose, which usually means the real question is whether you need both rather than whether they are safe together. This page lists the shared uses and how strong the evidence is for Gentian in each. That is a conversation for your prescriber, especially if Pemetrexed is being adjusted to a target.
How was the Gentian and Pemetrexed combination checked?
Interactions in our licensed database are recorded against drug classes. Pemetrexed is filed under 1 classification, and Gentian has documented interactions with 1 drug class — none of Pemetrexed'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 Gentian interact with any other medications?
Yes. Gentian has 172 documented drug interactions in our database — Pemetrexed 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 Pemetrexed interact with any supplements?
Yes. Pemetrexed has documented interactions with 4 supplements in our database — Gentian is not one of them. The Pemetrexed 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

Gentian monograph Uses, safety profile, and every drug interaction in one place Pemetrexed Injection drug information The full plain-English guide to this medication Pemetrexed supplement interactions Every supplement checked against Pemetrexed, 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 5 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Pemetrexed and Gentian?

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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.