Drug & supplement interaction

Cassava + 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 Cassava 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

Cassava 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 Cassava 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.

Cassava safety at a glance

Cassava overall Use caution Properly cooked cassava is a common food, but raw or poorly processed cassava can cause cyanide poisoning.
Pregnancy Possibly Unsafe When used orally as a food, especially in large quantities. Animal research suggests that consuming milled cassava powder as 80% of the diet during the first 15... Read the full pregnancy detail
Breastfeeding Possibly Unsafe When used orally in food amounts, especially in large quantities. Excess consumption of cassava during lactation may increase the risk of exposing the infant to... 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 Cassava? 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. Cassava has documented interactions with 1 drug class — the most serious being thyroid hormone (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

Cassava Does Interact With Other Medications

Cassava has 16 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 16 No known interaction 2,814 (incl. Tadalafil)
Taking anything else?

Check Another of Your Medications Against Cassava

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

What to actually watch for

No Interaction Found — But Data Suggests Cassava 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

    Cassava

    “Orally, cassava may cause cyanide poisoning. Cassava, especially the bitter variety, contains cyanogenic glycosides. If not removed during processing, these constituents are converted to cyanogens. Symptoms of cyanide poisoning can include vomiting, nausea, stomach pains, and diarrhea, as well as dizziness, weakness, and headache..”

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

    6 sources cited
    1. 26585. Cardoso AP, Mirione E, Ernesto M, et al. Processing of cassava roots to remove cyanogens. Journal of Food Composition and Analysis 2005;18(5):451-60. DOI
    2. 25841. Hernandez T, Lundquist P, Oliveira L, et al. Fate in humans of dietary intake of cyanogenic glycosides from roots of sweet cassava consumed in Cuba. Nat Toxins 1995;3(2):114-7. PubMed
    3. 25843. Ariffin WA, Choo KE, Karnaneedi S. Cassava (ubi kayu) poisoning in children. Med J Malaysia 1992;47(3):231-4.
    4. 25844. Tylleskar T, Banea M, Bikangi N, et al. Cassava cyanogens and konzo, an upper motoneuron disease found in Africa. Lancet 1992;339(8787):208-11. PubMed
    5. 25854. Assan R, Assan D, Thiebaut MF, et al. [Diabetogenic tropical pancreatitis]. Diabete Metab 1988;14(3):299-312.
    6. 25856. Balakrishnan V, Unnikrishnan AG, Thomas V, et al. Chronic pancreatitis. A prospective nationwide study of 1,086 subjects from India. JOP 2008;9(5):593-600.

    “Orally, cassava can cause cyanide poisoning. Cassava, especially the bitter variety, contains cyanogenic glycosides. If not removed during processing, these constituents are converted to cyanogens. Neurological symptoms of cyanide poisoning include dizziness, weakness, and headache.”

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

    6 sources cited
    1. 26585. Cardoso AP, Mirione E, Ernesto M, et al. Processing of cassava roots to remove cyanogens. Journal of Food Composition and Analysis 2005;18(5):451-60. DOI
    2. 25844. Tylleskar T, Banea M, Bikangi N, et al. Cassava cyanogens and konzo, an upper motoneuron disease found in Africa. Lancet 1992;339(8787):208-11. PubMed
    3. 25859. Cliff J, Lundqvist P, Martensson J, et al. Association of high cyanide and low sulphur intake in cassava-induced spastic paraparesis. Lancet 1985;2(8466):1211-3. PubMed
    4. 25860. Paula Cardoso A, Ernesto M, Nicala D, et al. Combination of cassava flour cyanide and urinary thiocyanate measurements of school children in Mozambique. Int J Food Sci Nutr 2004;55(3):183-90. PubMed
    5. 25861. Dumas M, Giordano C, Ndiaye IP, et al. [The concept of tropical neuromyelopathy]. Bull Soc Pathol Exot Filiales 1988;81(2):183-8.
    6. 99804. Banea JP, Bradbury JH, Mandombi C, et al. Control of konzo by detoxification of cassava flour in three villages in the Democratic Republic of Congo. Food Chem Toxicol. 2013 Oct;60:506-13. Epub 2013 Aug 11. PubMed

    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 Cassava but not commonly for Tadalafil: shortness of breath, an allergic reaction, a change in thyroid levels and loss of vision.

Effects for Tadalafil come from the ADVERSE REACTIONS section of its FDA label; effects for Cassava 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

Cassava in Pregnancy & Breastfeeding

Pregnancy Possibly Unsafe

When used orally as a food, especially in large quantities. Animal research suggests that consuming milled cassava powder as 80% of the diet during the first 15 days of pregnancy can cause teratogenic effects, including intrauterine growth restriction, limb defects, and abnormally small brain (microencephaly). Also, epidemiological evidence suggests that pregnant women who regularly consume dietary cassava in the form of gari during pregnancy have higher levels of thiocyanate, which has negative effects on fetal birthweight, compared to those who do not consume cassava. ...when applied intravaginally. Inserting 2-3 cm of cassava stalk into the vagina has been used to induce abortion and labor.

Lactation Possibly Unsafe

When used orally in food amounts, especially in large quantities. Excess consumption of cassava during lactation may increase the risk of exposing the infant to thiocyanate, which can negatively affect thyroid function in the infant.

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

We hold 35 real supplement products containing Cassava, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cassava. Even though Cassava 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 Cassava 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 Cassava
Steady interest

#1,209 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 Cassava reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Cassava 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 Cassava

What is Cassava?

Cassava
  • Dietary staple/source of carbohydrates
  • Fertility aid (to conceive twins)
  • Digestive support
  • General energy
  • Gluten-free flour alternative

Cassava is a starchy root vegetable that feeds millions of people worldwide, but it must be properly cooked or processed because the raw plant contains compounds that release cyanide. As a supplement, it is marketed for fertility and twin conception, but there is no good scientific evidence to support these claims. Always prepare cassava correctly and talk to your pharmacist or doctor before using cassava products for health reasons.

Manihot esculenta · Euphorbiaceae · Starchy root (tuber) and leaves · Whole root, flour, tapioca, dried powder, capsules

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

Cassava: dosing

There is no established or standardized dose for cassava as a supplement. As a food, it is simply prepared and eaten in normal serving sizes after proper cooking.For cassava supplements or flour products, follow the directions on the product label.

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

Read the full Cassava 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 & Cassava

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

0Major
16Moderate
0Minor
2,813No known interaction
16 Moderate 2,813 No interaction
Moderate

16 interactions

No interaction 2,813 drugs checked — show the list

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

Showing the 60 most looked-up of 2,813 medications checked with no known interaction — see the full Cassava list.

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

Cassava References

The 30 references that drive our Cassava 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. Hernandez T, Lundquist P, Oliveira L, et al. Fate in humans of dietary intake of cyanogenic glycosides from roots of sweet cassava consumed in Cuba. Nat Toxins 1995;3(2):114-7. PubMed
  2. Ariffin WA, Choo KE, Karnaneedi S. Cassava (ubi kayu) poisoning in children. Med J Malaysia 1992;47(3):231-4.
  3. Tylleskar T, Banea M, Bikangi N, et al. Cassava cyanogens and konzo, an upper motoneuron disease found in Africa. Lancet 1992;339(8787):208-11. PubMed
  4. Akindahunsi AA, Grissom FE, Adewusi SR, et al. Parameters of thyroid function in the endemic goitre of Akungba and Oke-Agbe villages of Akoko area of southwestern Nigeria. Afr J Med Med Sci 1998;27(3-4):239-42.
  5. Osman BA, Ng ML, Bakar AA, Khalid BA. The effect of cassava leave intake on thyroid hormone and urinary iodine. East Afr Med J 1993;70(5):314-5.
  6. Gaitan E, Cooksey RC, Legan J, et al. Antithyroid effects in vivo and in vitro of babassu and mandioca: a staple food in goiter areas of Brazil. Eur J Endocrinol 1994;131(2):138-44. PubMed
  7. Geelhoed GW. Metabolic maladaptation: individual and social consequences of medical intervention in correcting endemic hypothyroidism. Nutrition 1999;15(11-12):908-32. DOI
  8. Biassoni P, Ravera G, Bertocchi J, et al. Influence of dietary habits on thyroid status of a nomadic people, the Bororo shepherds, roaming a central African region affected by severe iodine deficiency. Eur J Endocrinol 1998;138(6):681-5. PubMed
  9. Delange F. The disorders induced by iodine deficiency. Thyroid 1994;4(1):107-28. PubMed
  10. Delange F. [The role of goitrogenic factors distinct from iodine deficiency in the etiology of goiter]. Ann Endocrinol (Paris) 1988;49(4-5):302-5.
  11. Assan R, Assan D, Thiebaut MF, et al. [Diabetogenic tropical pancreatitis]. Diabete Metab 1988;14(3):299-312.
  12. Balakrishnan V, Unnikrishnan AG, Thomas V, et al. Chronic pancreatitis. A prospective nationwide study of 1,086 subjects from India. JOP 2008;9(5):593-600.
  13. Cliff J, Lundqvist P, Martensson J, et al. Association of high cyanide and low sulphur intake in cassava-induced spastic paraparesis. Lancet 1985;2(8466):1211-3. PubMed
  14. Paula Cardoso A, Ernesto M, Nicala D, et al. Combination of cassava flour cyanide and urinary thiocyanate measurements of school children in Mozambique. Int J Food Sci Nutr 2004;55(3):183-90. PubMed
  15. Dumas M, Giordano C, Ndiaye IP, et al. [The concept of tropical neuromyelopathy]. Bull Soc Pathol Exot Filiales 1988;81(2):183-8.

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 Cassava and Tadalafil Together: Common Questions

Is it safe to take Cassava with Tadalafil?
We do not list a known interaction between Cassava 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 Cassava 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 Cassava and Tadalafil combination checked?
Interactions in our licensed database are recorded against drug classes. Tadalafil is filed under 5 classifications, and Cassava has documented interactions with 1 drug class — 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 Cassava interact with any other medications?
Yes. Cassava has 16 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 — Cassava 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

Cassava 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 30 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Tadalafil and Cassava?

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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.