Drug & supplement interaction

Gelsemium + Idelalisib

Idelalisib brand name: Zydelig.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Gelsemium and Idelalisib 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.

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Interaction report

Gelsemium and Idelalisib

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 Idelalisib and Gelsemium 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 Gelsemium at all — not against Idelalisib, 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.

Gelsemium safety at a glance

Gelsemium overall Avoid The crude plant is highly toxic and even small amounts can be life-threatening.
Pregnancy Unsafe When used orally due to toxicity. Read the full pregnancy detail
Breastfeeding Unsafe When used orally due to toxicity. Read the full breastfeeding detail

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.

Still wondering about combining Idelalisib and Gelsemium? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Gelsemium Itself Has Been Linked To

This is not an interaction — nothing below involves Idelalisib. It is the side-effect record for Gelsemium on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Gelsemium, this list is the first place to look. One entry is worth acting on rather than waiting out — marked below.

  • Muscle weakness / Trouble swallowing / A slow heartbeat / Seizures / Shortness of breath Worth acting on Additional detail

    “Orally, gelsemium can cause headache, drooping of the eyelid, double vision, difficulty swallowing, dizziness, muscle weakness or rigidity, seizures, dyspnea, and bradycardia. Death due to failure of respiratory muscles can occur (18).”

    Gelsemium · Natural Medicines adverse-effect record, reported in cluster headache.

    1 source cited
    1. 18. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  • Dizziness / Headache Additional detail

    Recorded for Gelsemium in the same Natural Medicines adverse-effect record shown under Muscle weakness / Trouble swallowing / A slow heartbeat / Seizures / Shortness of breath above.

Everything above comes from the Natural Medicines adverse-effect record for Gelsemium — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Idelalisib’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Idelalisib column appears here.

Special populations

Gelsemium in Pregnancy & Breastfeeding

Pregnancy And Lactation Unsafe

When used orally due to toxicity.

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

Everything else you take

See Every Supplement That Interacts With Idelalisib

This page covers Gelsemium only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Idelalisib 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 Idelalisib page

“Idelalisib (Zydelig) treats certain blood cancers, work that leaves little room for error, so start with the three major-rated entries on this page. Grapefruit raises idelalisib levels and the risk of side effects with them, St.”

Reviewed by 2 · Jul 18, 2026

Open the Idelalisib interaction page

One more smart check

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

We hold 2 real supplement products containing Gelsemium, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Gelsemium. Even though Gelsemium itself has no known interaction with Idelalisib, 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 Gelsemium and Idelalisib 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 Gelsemium
Steady interest

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

29 days ago today
Medication Idelalisib
Steady interest

#2,154 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 Gelsemium reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Gelsemium and Idelalisib 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 Gelsemium

What is Gelsemium?

  • Anxiety and nervousness
  • Headache and migraine
  • Flu-like symptoms
  • Nerve pain (neuralgia)
  • Stage fright

Gelsemium is a highly toxic flowering plant most often sold today in very dilute homeopathic forms for anxiety, headaches, and flu-like symptoms. There is little reliable scientific evidence that it works, and the raw plant is dangerously poisonous, so it should never be used in crude or concentrated form. Always talk to a pharmacist or doctor before trying it.

Gelsemium sempervirens · Gelsemiaceae · Root and rhizome (also used in homeopathic preparations) · Homeopathic pellets and liquid dilutions, tinctures

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

Gelsemium: dosing

There is no established safe dose for the Gelsemium plant, and the crude herb should not be taken because of its toxicity. Homeopathic products use standardized dilution scales rather than measured milligram amounts of plant.If you choose to use a homeopathic Gelsemium product, follow the directions on the label exactly and do not exceed them.

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

Read the full Gelsemium monograph & all interactions
Medication

About Idelalisib

What Is Idelalisib Used For?

Brand name: Zydelig

Zydelig (idelalisib) is approved to treat relapsed chronic lymphocytic leukemia (CLL) — a cancer of the blood and bone marrow — when used together with rituximab. It is specifically for patients who have already received treatment and for whom rituximab alone would be appropriate due to other health conditions.

Zydelig is not approved or recommended as a first-line (initial) treatment for CLL or any other cancer, including small lymphocytic lymphoma (SLL) or follicular lymphoma (FL). It is also not approved in combination with bendamustine and rituximab, or with rituximab alone, for FL, SLL, or other slow-growing non-Hodgkin lymphomas.

Most-Reported Side Effects for Idelalisib

From FAERS, the FDA’s public side-effect reporting system (7,040 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Disease progression 1,225 reports
Diarrhea 771 reports
Pneumonia 437 reports
Fever 375 reports
Fatigue 301 reports
See full Idelalisib drug information
Keep checking

Other Drugs & Gelsemium

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

0Major
0Moderate
0Minor
2,829No known interaction
No interaction 2,829 drugs checked — show the list
Evidence & sources

Gelsemium References

The 2 references that drive our Gelsemium 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. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  2. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

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 Gelsemium and Idelalisib Together: Common Questions

Is it safe to take Gelsemium with Idelalisib?
We do not list a known interaction between Gelsemium and Idelalisib. 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.
Does Idelalisib interact with any supplements?
Yes. Idelalisib has documented interactions with 143 supplements in our database — Gelsemium is not one of them. The Idelalisib interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Idelalisib and Gelsemium?

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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.