Drug & supplement interaction

Lily-of-the-valley + Finasteride

Finasteride brand names: Propecia, Proscar.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Oct 4, 2026
The bottom line No known interaction

We found no known interaction between Lily-of-the-valley and Finasteride 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

Lily-of-the-valley and Finasteride

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 Finasteride and Lily-of-the-valley 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.

Lily-of-the-valley safety at a glance

Lily-of-the-valley overall Avoid All parts are poisonous and can cause life-threatening heart problems.
Pregnancy Likely Unsafe When used orally for self-medication. Avoid using. Read the full pregnancy detail
Breastfeeding Likely Unsafe When used orally for self-medication. 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 Finasteride and Lily-of-the-valley? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Finasteride

Interactions in our licensed database are recorded against drug classes, not just single drug names. Finasteride is filed under 3 classifications — including cytochrome p450 3a4 (cyp3a4) substrates, oral drugs. Lily-of-the-valley has documented interactions with 8 drug classes — the most serious being corticosteroids (major), digoxin (lanoxin) (major) and quinine (major) — and none of Finasteride’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

Lily-of-the-valley Does Interact With Other Medications

Lily-of-the-valley has 26 major, 131 moderate known drug interactions in our database — Finasteride isn’t one of them. If you take anything else, check it against the full list below.

Major 26 Moderate 131 No known interaction 2,673 (incl. Finasteride)
Taking anything else?

Check Another of Your Medications Against Lily-of-the-valley

Covers the 2,830 medications we’ve checked against Lily-of-the-valley. Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests Lily-of-the-valley and Finasteride May Share a Side Effect

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.

  • Headache Additional detail

    Lily-of-the-valley

    “Orally, lily-of-the-valley can cause headache and stupor (18). Visual color disturbances can also occur (18).”

    Lily-of-the-valley · 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.

    Finasteride

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

Reported for Lily-of-the-valley but not commonly for Finasteride: raised blood pressure, an irregular heartbeat, a slow heartbeat and vomiting.

Effects for Finasteride come from the ADVERSE REACTIONS section of its FDA label; effects for Lily-of-the-valley come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 59,984 voluntary FDA FAERS reports for Finasteride that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Lily-of-the-valley in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Unsafe

When used orally for self-medication. 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

From our Q&A

Questions About Lily-of-the-valley or Finasteride

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Lily-of-the-valley or Finasteride, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Finasteride

This page covers Lily-of-the-valley only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Finasteride page lists 138 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 · 94 moderate · 41 minor.

From our pharmacist’s overview on the Finasteride page

“The supplement list for finasteride (Propecia, Proscar) is one I would read carefully rather than skim, because three of its 138 entries are rated major. Almost everything here works through the same liver enzyme, CYP3A4, that clears finasteride.”

Reviewed by 2 · Jul 18, 2026

Open the Finasteride interaction page

One more smart check

Taking Lily-of-the-valley as Part of a Dietary Supplement Product? Check It for Interactions

We hold 10 real supplement products containing Lily-of-the-valley, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Lily-of-the-valley. Even though Lily-of-the-valley itself has no known interaction with Finasteride, 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 Lily-of-the-valley and Finasteride 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 Lily-of-the-valley
Steady interest

#1,162 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Finasteride
Top 25%

#445 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 Lily-of-the-valley reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified October 4, 2026. The Lily-of-the-valley and Finasteride 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 Lily-of-the-valley

What is Lily-of-the-valley?

Lily-of-the-valley
  • Heart failure (historical)
  • Irregular heartbeat (historical)
  • Fluid retention/edema
  • General heart tonic (traditional)

Lily-of-the-valley is a poisonous plant that contains powerful heart-affecting compounds called cardiac glycosides, similar to the drug digoxin. While it was used historically for heart conditions, it is dangerous and is not recommended for self-treatment. All parts of the plant are toxic, and accidental poisoning can be life-threatening.

Convallaria majalis · Asparagaceae · Dried flowering tops, leaves, and roots · Tincture, dried herb extract, homeopathic preparations (rarely used today)

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

Lily-of-the-valley: dosing

There is no established safe dose of lily-of-the-valley for self-care, and it should not be used. Do not attempt to make or use any home preparation of this plant.

From our Lily-of-the-valley monograph — the full record covers uses, side effects and every documented interaction.

Read the full Lily-of-the-valley monograph & all interactions
Medication

About Finasteride

What Is Finasteride Used For?

Brand names: Propecia, Proscar

Finasteride tablets are used in men for two main purposes, depending on the product. Which one you take depends on the strength and brand your prescriber chose.

Enlarged prostate (BPH): Proscar and finasteride tablets labeled for BPH treat symptomatic BPH in men with an enlarged prostate. They improve symptoms and reduce the risk of acute urinary retention (suddenly being unable to urinate). They also reduce the risk of needing surgery such as TURP or prostatectomy. With the alpha-blocker doxazosin, they reduce the risk of BPH symptoms getting worse. They are not approved to prevent prostate cancer.

Male pattern hair loss: Propecia and finasteride tablets labeled for hair loss treat male pattern hair loss (androgenetic alopecia) in men only. Efficacy in bitemporal recession (receding at the temples) has not been established. These products are not for use in women.

Most-Reported Side Effects for Finasteride

From FAERS, the FDA’s public side-effect reporting system (59,984 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Erectile dysfunction 4,195 reports
Fatigue 4,093 reports
Depression 3,674 reports
Anxiety 3,092 reports
Adverse drug reaction 2,768 reports
See full Finasteride drug information
Keep checking

Other Drugs & Lily-of-the-valley

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

26Major
131Moderate
0Minor
2,672No known interaction
26 Major 131 Moderate 2,672 No interaction
Major

26 interactions

Moderate

131 interactions

Showing 60 of 131 moderate interactions — see all 131 on the Lily-of-the-valley page.

No interaction 2,672 drugs checked — show the list

We also checked Lily-of-the-valley against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,672 medications checked with no known interaction — see the full Lily-of-the-valley list.

See the full Lily-of-the-valley interactions page
See every supplement checked against Finasteride, ranked by severity
Evidence & sources

Lily-of-the-valley References

The 7 references that drive our Lily-of-the-valley 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. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  3. Ellenhorn MJ, et al. Ellenhorn's Medical Toxicology: Diagnoses and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams & Wilkins, 1997.
  4. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  5. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  6. Burnham TH, ed. Drug Facts and Comparisons, Updated Monthly. Facts and Comparisons, St. Louis, MO.
  7. Alexandre J, Foucault A, Coutance G, et al. Digitalis intoxication induced by an acute accidental poisoning by lily of the valley. Circulation 2012 Feb 28;125(8):1053-5. PubMed

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 Lily-of-the-valley and Finasteride Together: Common Questions

Is it safe to take Lily-of-the-valley with Finasteride?
We do not list a known interaction between Lily-of-the-valley and Finasteride. 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 Lily-of-the-valley and Finasteride have any of the same side effects?
Yes — our sources link each of them separately to one 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.
How was the Lily-of-the-valley and Finasteride combination checked?
Interactions in our licensed database are recorded against drug classes. Finasteride is filed under 3 classifications, and Lily-of-the-valley has documented interactions with 8 drug classes — none of Finasteride'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 Lily-of-the-valley interact with any other medications?
Yes. Lily-of-the-valley has 157 documented drug interactions in our database — Finasteride 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 Finasteride interact with any supplements?
Yes. Finasteride has documented interactions with 138 supplements in our database — Lily-of-the-valley is not one of them. The Finasteride 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

Lily-of-the-valley monograph Uses, safety profile, and every drug interaction in one place Finasteride drug information The full plain-English guide to this medication Finasteride supplement interactions Every supplement checked against Finasteride, 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 7 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Finasteride and Lily-of-the-valley?

Our pharmacists answer your medication & supplement questions — free.

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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.