Drug & supplement interaction

Swamp Milkweed + Valganciclovir

Valganciclovir brand name: Valcyte.

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 Swamp Milkweed and Valganciclovir 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 Valganciclovir 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.

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Interaction report

Swamp Milkweed and Valganciclovir

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 Valganciclovir and Swamp Milkweed 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.

Swamp Milkweed safety at a glance

Swamp Milkweed overall Use caution The plant contains toxic sap and cardiac glycoside-like compounds; it is not a well-studied or clearly safe supplement.
Pregnancy Likely Unsafe When used orally due to presence of cardioactive steroids; avoid using. Read the full pregnancy detail
Breastfeeding Likely Unsafe When used orally due to presence of cardioactive steroids; avoid using. 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 Valganciclovir and Swamp Milkweed? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Valganciclovir

Interactions in our licensed database are recorded against drug classes, not just single drug names. Valganciclovir is filed under a single classification — oral drugs. Swamp Milkweed has documented interactions with 7 drug classes — the most serious being digoxin (lanoxin) (major), quinine (major) and corticosteroids (moderate) — and none of Valganciclovir’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

Swamp Milkweed Does Interact With Other Medications

Swamp Milkweed has 3 major, 153 moderate known drug interactions in our database — Valganciclovir isn’t one of them. If you take anything else, check it against the full list below.

Major 3 Moderate 153 No known interaction 2,674 (incl. Valganciclovir)
Taking anything else?

Check Another of Your Medications Against Swamp Milkweed

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

What to actually watch for

No Interaction Found — But Data Suggests Swamp Milkweed and Valganciclovir 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. One of them is worth acting on rather than waiting out — marked below.

  • An irregular heartbeat Worth acting on Additional detail

    Swamp Milkweed

    “Orally, swamp milkweed contains cardiac glycosides, which can cause serious adverse effects.

    Serious Adverse Effects (Rare):

    Orally: Swamp milkweed contains toxic cardiac glycosides that may cause cardiac arrhythmia and death.”

    Swamp Milkweed · Natural Medicines adverse-effect record, reported in arrhythmia.

    “Orally, the cardiac glycosides in swamp milkweed may cause cardiac arrhythmias (18).”

    Swamp Milkweed · Natural Medicines adverse-effect record, reported in arrhythmia.

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

    Valganciclovir

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

  • Vomiting Additional detail

    Swamp Milkweed

    “Orally, large amounts of swamp milkweed can cause vomiting (18).”

    Swamp Milkweed · Natural Medicines adverse-effect record, reported in nausea and vomiting.

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

    Valganciclovir

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

  • Headache Additional detail

    Swamp Milkweed

    “Orally, the cardiac glycosides in swamp milkweed may cause headache and stupor (18). Visual color disturbances may also occur (18).”

    Swamp Milkweed · 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.

    Valganciclovir

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

Effects for Valganciclovir come from the ADVERSE REACTIONS section of its FDA label; effects for Swamp Milkweed 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

Swamp Milkweed in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Unsafe

When used orally due to presence of cardioactive steroids; 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

How to take them

Some Valganciclovir Products Have a Food Rule — Swamp Milkweed Should Not Break It

At least one FDA label for a product containing Valganciclovir says to take it with food. If you take Swamp Milkweed on an empty stomach out of habit, keep them separate — and take Valganciclovir with a meal where the label says to.

This may not be true of your version. Food instructions belong to the product, not the ingredient: two Valganciclovir 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.

2 DOSAGE AND ADMINISTRATION Adult Dosage ( 2.2 ) Treatment of CMV retinitis Induction: 900 mg (two 450 mg tablets) twice a day for 21 days Maintenance: 900 mg (two 450 mg tablets) once a day Prevention of CMV disease in heart or kidney-pancreas transplant patients 900 mg (two 450 mg tablets) once a day within 10 days of transplantation until 100 days post-transplantation Prevention of CMV disease

From the Dosage and Administration section of the FDA label we read for Valganciclovir — 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.

Everything else you take

See Every Supplement That Interacts With Valganciclovir

This page covers Swamp Milkweed only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Valganciclovir page lists 17 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 · 7 moderate · 9 minor.

From our pharmacist’s overview on the Valganciclovir page

“Valganciclovir (Valcyte) treats cytomegalovirus, an infection that can blind or seriously sicken transplant recipients and others with weakened immunity, so each dose must be absorbed reliably. All 17 supplements on this list threaten exactly that, changing how much drug moves from gut to bloodstream, and that pairing deserves genuine…”

Reviewed by 2 · Jul 18, 2026

Open the Valganciclovir interaction page

How much people look this up

Where Swamp Milkweed and Valganciclovir 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 Swamp Milkweed
Steady interest

#1,032 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Valganciclovir
Steady interest

#2,559 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 Swamp Milkweed reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Swamp Milkweed and Valganciclovir 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 Swamp Milkweed

What is Swamp Milkweed?

  • Traditional digestive remedy
  • Diuretic (increasing urine)
  • Cough and respiratory complaints
  • Worm or parasite remedy (folk use)
  • Pollinator/garden plant rather than medicine

Swamp Milkweed is a native North American wetland plant best known today as a butterfly and pollinator garden plant, not a proven medicine. It contains toxic milky sap with cardiac glycoside-like compounds, and there is very little reliable human research to support any health use. Because of its potential toxicity, it should not be used as a supplement without professional guidance.

Asclepias incarnata · Apocynaceae · Root, and historically other parts of the plant · Dried root, tinctures, and traditional decoctions (rarely sold as a commercial supplement)

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

Swamp Milkweed: dosing

There is no established safe or standardized dose for Swamp Milkweed. It is not a mainstream supplement, and reliable products with verified content are not generally available.Because of the plant's toxicity and the lack of research, we cannot recommend any specific amount. For most people, the safest approach is to enjoy Swamp Milkweed as a garden plant rather than to consume it.

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

Read the full Swamp Milkweed monograph & all interactions
Medication

About Valganciclovir

What Is Valganciclovir Used For?

Brand name: Valcyte

Valganciclovir treats CMV retinitis — a viral infection that can damage the retina and threaten vision — in adults with AIDS. It is also used to prevent CMV disease in adults who have had a kidney, heart, or kidney-pancreas transplant and are at high risk for infection.

In children, valganciclovir is used to prevent CMV disease in pediatric kidney transplant patients ages 4 months to 16 years, and in pediatric heart transplant patients ages 1 month to 16 years. The oral solution form is specifically indicated for these pediatric uses.

Most-Reported Side Effects for Valganciclovir

From FAERS, the FDA’s public side-effect reporting system (18,743 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Cytomegalovirus infection 1,821 reports
Neutropenia 1,147 reports
Fever 957 reports
Leukopenia 941 reports
Diarrhea 933 reports
See full Valganciclovir drug information
Keep checking

Other Drugs & Swamp Milkweed

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

3Major
153Moderate
0Minor
2,673No known interaction
3 Major 153 Moderate 2,673 No interaction
Major

3 interactions

Moderate

153 interactions

Showing 60 of 153 moderate interactions — see all 153 on the Swamp Milkweed page.

No interaction 2,673 drugs checked — show the list

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

Showing the 60 most looked-up of 2,673 medications checked with no known interaction — see the full Swamp Milkweed list.

See the full Swamp Milkweed interactions page
See every supplement checked against Valganciclovir, ranked by severity
Evidence & sources

Swamp Milkweed References

The 3 references that drive our Swamp Milkweed 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. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
  2. Ellenhorn MJ, et al. Ellenhorn's Medical Toxicology: Diagnoses and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams & Wilkins, 1997.
  3. 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 Swamp Milkweed and Valganciclovir Together: Common Questions

Is it safe to take Swamp Milkweed with Valganciclovir?
We do not list a known interaction between Swamp Milkweed and Valganciclovir. 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 Swamp Milkweed and Valganciclovir 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.
Should I take Swamp Milkweed and Valganciclovir at the same time of day?
At least one FDA label for a product containing Valganciclovir says to take it with food. If you take Swamp Milkweed on an empty stomach out of habit, keep them separate and take Valganciclovir with a meal where the label says to. Food instructions belong to the product rather than the ingredient — two Valganciclovir products can differ — so check the directions on your own box. This is about absorption, not an interaction.
How was the Swamp Milkweed and Valganciclovir combination checked?
Interactions in our licensed database are recorded against drug classes. Valganciclovir is filed under 1 classification, and Swamp Milkweed has documented interactions with 7 drug classes — none of Valganciclovir'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 Swamp Milkweed interact with any other medications?
Yes. Swamp Milkweed has 156 documented drug interactions in our database — Valganciclovir 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 Valganciclovir interact with any supplements?
Yes. Valganciclovir has documented interactions with 17 supplements in our database — Swamp Milkweed is not one of them. The Valganciclovir 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

Swamp Milkweed monograph Uses, safety profile, and every drug interaction in one place Valganciclovir drug information The full plain-English guide to this medication Valganciclovir supplement interactions Every supplement checked against Valganciclovir, 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 3 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Valganciclovir and Swamp Milkweed?

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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.