Drug & supplement interaction

Belladonna + Tadalafil

Tadalafil brand names: Cialis, Tadliq.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Belladonna and Tadalafil 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

Belladonna and Tadalafil

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 Tadalafil and Belladonna 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.

Belladonna safety at a glance

Belladonna overall Avoid Belladonna is poisonous and unsafe to take on your own outside of regulated, professionally supervised products.
Pregnancy Avoid Avoid during pregnancy because belladonna's alkaloids are toxic and effects on the baby are not established.
Breastfeeding Likely Unsafe When used orally. Belladonna can reduce milk production and is secreted into breast milk. 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 Tadalafil and Belladonna? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Tadalafil

Interactions in our licensed database are recorded against drug classes, not just single drug names. Tadalafil is filed under 5 classifications — including phosphodiesterase-5 inhibitors, vasodilators, cytochrome p450 3a4 (cyp3a4) substrates. Belladonna has documented interactions with 2 drug classes — the most serious being anticholinergic drugs (moderate) and cisapride (propulsid) (moderate) — and none of Tadalafil’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

Belladonna Does Interact With Other Medications

Belladonna has 196 moderate known drug interactions in our database — Tadalafil isn’t one of them. If you take anything else, check it against the full list below.

Moderate 196 No known interaction 2,634 (incl. Tadalafil)
Taking anything else?

Check Another of Your Medications Against Belladonna

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

What to actually watch for

No Interaction Found — But Data Suggests Belladonna and Tadalafil 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 reported in 11.1% of FDA reports for Tadalafil Additional detail

    Belladonna

    “Orally, belladonna can cause anticholinergic side effects such as memory and attention impairment, headache, and confusion.”

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

    3 sources cited
    1. 553. Jaspersen-Schib R, Theus L, Guirguis-Oeschger M, et al. [Serious plant poisonings in Switzerland 1966-1994. Case analysis from the Swiss Toxicology Information Center]. Schweiz Med Wochenschr 1996;126:1085-98.
    2. 34163. Goldsmith SR, Frank I, and Ungerleider JT. Poisoning from ingestion of a stramonium-belladonna mixture: flower power gone sour. J.A.M.A 4-8-1968;204(2):169-170. DOI
    3. 34180. Cummins BM, Obetz SW, Wilson MR, and et al. Belladonna poisoning as a facet of psychodelia. Jama 1968;204(11):153. DOI

    Tadalafil

    Listed in the ADVERSE REACTIONS section of the FDA label for Tadalafil, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

Reported for Belladonna but not commonly for Tadalafil: trouble passing urine, blurred vision, constipation and raised blood pressure.

Effects for Tadalafil come from the ADVERSE REACTIONS section of its FDA label; effects for Belladonna come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 98,103 voluntary FDA FAERS reports for Tadalafil 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

Belladonna in Pregnancy & Breastfeeding

Lactation Likely Unsafe

When used orally. Belladonna can reduce milk production and is secreted into breast milk.

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 Belladonna or Tadalafil

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Belladonna or Tadalafil, 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 Tadalafil

This page covers Belladonna only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Tadalafil page lists 144 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Mistletoe (major), Grapefruit (major), Hawthorn (major) and St. John's Wort (major).

By severity: 5 major · 98 moderate · 41 minor.

From our pharmacist’s overview on the Tadalafil page

“Grapefruit juice is the first thing to know about if you take tadalafil (Cialis, Tadliq). It blocks CYP3A4, the enzyme that clears the drug, so blood levels climb and side effects like a steep drop in blood pressure become more likely.”

Reviewed by 2 · Jul 18, 2026

Open the Tadalafil interaction page

One more smart check

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

We hold 6 real supplement products containing Belladonna, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Belladonna. Even though Belladonna itself has no known interaction with Tadalafil, 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 Belladonna and Tadalafil 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 Belladonna
Top half

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

29 days ago today
Medication Tadalafil
Top 1%

#16 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 Belladonna reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Belladonna and Tadalafil records this page draws on were last updated July 11, 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 Belladonna

What is Belladonna?

  • Digestive cramps and spasms
  • Cold and flu symptoms (homeopathic)
  • Teething pain (homeopathic)
  • Motion sickness and nausea
  • Excess sweating or secretions
  • Pain and muscle spasm (topical plasters)

Belladonna is a highly toxic plant whose alkaloids (like atropine and scopolamine) are powerful medicines used only in carefully controlled, regulated forms. The raw plant and unregulated products can cause serious poisoning, and homeopathic versions have little proof of benefit. Never self-treat with belladonna without guidance from a doctor or pharmacist.

Atropa belladonna · Solanaceae · Leaves, roots, and berries · Homeopathic tablets and pellets, tinctures, topical plasters, and standardized prescription alkaloid extracts

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

Belladonna: dosing

There is no safe, established "supplement" dose of belladonna for self-care. The line between a helpful dose and a toxic dose is dangerously narrow, and the amount of alkaloid in raw plant material can vary widely.Prescription belladonna-alkaloid medicines are dosed by a doctor and pharmacist. Homeopathic products are highly diluted and labeled in their own units; follow the product label exactly and keep them away from children.Do not try to make or dose belladonna products yourself.

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

Read the full Belladonna monograph & all interactions
Medication

About Tadalafil

What Is Tadalafil Used For?

Brand names: Cialis, Tadliq

Tadalafil tablets (including Cialis and generic tadalafil) are used to treat erectile dysfunction (ED), the symptoms of benign prostatic hyperplasia (BPH — an enlarged prostate), or both conditions together. When used with the drug finasteride to start BPH treatment, this combination is recommended for up to 26 weeks.

Adcirca, Alyq (tablets), and Tadliq (oral suspension) are indicated specifically for pulmonary arterial hypertension (PAH — high blood pressure in the lungs), to improve the ability to exercise.

Most-Reported Side Effects for Tadalafil

From FAERS, the FDA’s public side-effect reporting system (99,210 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Dyspnea 11,917 reports
Headache 10,982 reports
Diarrhea 8,020 reports
Nausea 6,697 reports
Fatigue 6,080 reports
See full Tadalafil drug information
Keep checking

Other Drugs & Belladonna

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

0Major
196Moderate
0Minor
2,633No known interaction
196 Moderate 2,633 No interaction
Moderate

196 interactions

Showing 60 of 196 moderate interactions — see all 196 on the Belladonna page.

No interaction 2,633 drugs checked — show the list

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

Showing the 60 most looked-up of 2,633 medications checked with no known interaction — see the full Belladonna list.

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

Belladonna References

The 20 references that drive our Belladonna 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. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  4. Jaspersen-Schib R, Theus L, Guirguis-Oeschger M, et al. [Serious plant poisonings in Switzerland 1966-1994. Case analysis from the Swiss Toxicology Information Center]. Schweiz Med Wochenschr 1996;126:1085-98.
  5. Corazziari, E., Bontempo, I., and Anzini, F. Effects of cisapride on distal esophageal motility in humans. Dig Dis Sci 1989;34(10):1600-1605. PubMed
  6. Heindl, S., Binder, C., Desel, H., Matthies, U., Lojewski, I., Bandelow, B., Kahl, G. F., and Chemnitius, J. M. [Etiology of initially unexplained confusion of excitability in deadly nightshade poisoning with suicidal intent. Symptoms, differential diagn
  7. Walach, H., Koster, H., Hennig, T., and Haag, G. The effects of homeopathic belladonna 30CH in healthy volunteers -- a randomized, double-blind experiment. J.Psychosom.Res. 2001;50(3):155-160. PubMed
  8. Davidov, M. I. [Factors predisposing to acute urine retention in patients with prostatic adenoma]. Urologiia. 2007;(2):25-31.
  9. Williams HC and du Vivier A. Belladonna plaster--not as bella as it seems. Contact Dermatitis 1990;23(2):119-120.
  10. Stieg, R. L. Double-blind study of belladonna-ergotamine-phenobarbital for interval treatment of recurrent throbbing headache. Headache 1977;17(3):120-124. PubMed
  11. Shader RI and Greenblatt DJ. Uses and toxicity of belladonna alkaloids and synthetic anticholinergics. Seminars in Psychiatry 1971;3(4):449-476.
  12. Gabel MC. Purposeful ingestion of belladonna for hallucinatory effects. J.Pediatr. 1968;72(6):864-866. PubMed
  13. Goldsmith SR, Frank I, and Ungerleider JT. Poisoning from ingestion of a stramonium-belladonna mixture: flower power gone sour. J.A.M.A 4-8-1968;204(2):169-170. DOI
  14. Schneider, F., Lutun, P., Kintz, P., Astruc, D., Flesch, F., and Tempe, J. D. Plasma and urine concentrations of atropine after the ingestion of cooked deadly nightshade berries. J Toxicol Clin Toxicol 1996;34(1):113-117. PubMed
  15. Ceha LJ, Presperin C, Young E, and et al. Anticholinergic toxicity from nightshade berry poisoning responsive to physostigmine. The Journal of Emergency Medicine 1997;15(1):65-69. 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 Belladonna and Tadalafil Together: Common Questions

Is it safe to take Belladonna with Tadalafil?
We do not list a known interaction between Belladonna and Tadalafil. 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 Belladonna and Tadalafil 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 Belladonna and Tadalafil combination checked?
Interactions in our licensed database are recorded against drug classes. Tadalafil is filed under 5 classifications, and Belladonna has documented interactions with 2 drug classes — none of Tadalafil'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 Belladonna interact with any other medications?
Yes. Belladonna has 196 documented drug interactions in our database — Tadalafil 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 Tadalafil interact with any supplements?
Yes. Tadalafil has documented interactions with 144 supplements in our database — Belladonna is not one of them. The Tadalafil 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

Belladonna monograph Uses, safety profile, and every drug interaction in one place Tadalafil drug information The full plain-English guide to this medication Tadalafil supplement interactions Every supplement checked against Tadalafil, 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 20 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Tadalafil and Belladonna?

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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.