Drug & supplement interaction

Gelsemium + Megestrol Acetate

Megestrol Acetate brand names: Megestrol, Megace.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Gelsemium and Megestrol Acetate 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

Gelsemium and Megestrol Acetate

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 Megestrol Acetate 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 Megestrol Acetate, 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 Megestrol Acetate and Gelsemium? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Gelsemium and Megestrol Acetate 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. 2 of them are worth acting on rather than waiting out — marked below.

  • Seizures / Shortness of breath Worth acting on Additional detail

    Gelsemium

    “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.

    Megestrol Acetate

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

  • Headache Additional detail

    Gelsemium

    Recorded for Gelsemium in the same Natural Medicines adverse-effect record shown under Seizures / Shortness of breath above.

    Megestrol Acetate

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

Reported for Gelsemium but not commonly for Megestrol Acetate: trouble swallowing, muscle weakness, a slow heartbeat and dizziness.

Effects for Megestrol Acetate come from the ADVERSE REACTIONS section of its FDA label; effects for Gelsemium 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.

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 Megestrol Acetate

This page covers Gelsemium only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Megestrol Acetate page lists 18 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 · 8 moderate · 9 minor.

From our pharmacist’s overview on the Megestrol Acetate page

“Megestrol acetate (Megace) is usually prescribed to restore appetite and weight in people who are seriously ill, so the drug only helps if it actually gets absorbed. That is exactly where this list earns real caution.”

Reviewed by 2 · Jul 18, 2026

Open the Megestrol Acetate 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 Megestrol Acetate, 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 Megestrol Acetate 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

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

29 days ago today
Medication Megestrol Acetate
Steady interest

#1,430 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 Megestrol Acetate 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 Megestrol

What Is Megestrol Used For?

Brand names: Megestrol, Megace

Megestrol acetate is used for two distinct purposes depending on the formulation. Megestrol Acetate oral suspension is indicated for treating anorexia (loss of appetite), cachexia (severe weight loss and muscle wasting), or unexplained significant weight loss in patients with a diagnosis of AIDS.

Megestrol Acetate tablets are used for the palliative treatment — meaning to ease symptoms, not cure — of advanced breast cancer or endometrial (uterine lining) cancer that is recurrent, inoperable, or has spread to other parts of the body. Tablets are not a replacement for surgery, radiation, or chemotherapy.

Most-Reported Side Effects for Megestrol Acetate

From FAERS, the FDA’s public side-effect reporting system (0 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Fatigue 353 reports
Diarrhea 352 reports
Decreased appetite 276 reports
Asthenia 273 reports
Nausea 268 reports
See full Megestrol 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 Megestrol Acetate Together: Common Questions

Is it safe to take Gelsemium with Megestrol Acetate?
We do not list a known interaction between Gelsemium and Megestrol Acetate. 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 Gelsemium and Megestrol Acetate have any of the same side effects?
Yes — our sources link each of them separately to 3 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.
Does Megestrol Acetate interact with any supplements?
Yes. Megestrol Acetate has documented interactions with 18 supplements in our database — Gelsemium is not one of them. The Megestrol Acetate 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 Megestrol Acetate 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.