Drug & supplement interaction

Lactoferrin + Tadalafil

Tadalafil brand names: Cialis, Tadliq.

No Known Interaction
The bottom line No known interaction

We found no known interaction between Lactoferrin 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.

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Interaction report

Lactoferrin 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 Lactoferrin 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 Lactoferrin at all — not against Tadalafil, 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.

Lactoferrin safety at a glance

Lactoferrin overall Use caution Generally well tolerated short-term, but high-quality long-term safety data are limited.
Pregnancy Likely Safe When used orally in amounts commonly found in foods. Lactoferrin has Generally Regarded as Safe (GRAS) status in the US. Read the full pregnancy detail
Breastfeeding Likely Safe When used orally in amounts commonly found in foods. Lactoferrin has Generally Regarded as Safe (GRAS) status in the US. There is insufficient reliable informat... 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 Lactoferrin? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Lactoferrin Itself Has Been Linked To

This is not an interaction — nothing below involves Tadalafil. It is the side-effect record for Lactoferrin on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Lactoferrin, this list is the first place to look. 2 entries are worth acting on rather than waiting out — marked below.

  • A bowel blockage Worth acting on Additional detail

    “Orally, bovine and human recombinant lactoferrin are well tolerated when used in typical doses. However, hjgher doses of 7.2 grams daily increase the risk of side effects and decrease tolerability.

    Topically, there is a limited amount of information on the adverse effects of lactoferrin.

    Intravaginally, no adverse effects have been reported.”

    Lactoferrin · Natural Medicines adverse-effect record, reported in constipation.

    “Orally, lactoferrin has been reported to cause diarrhea in some patients. At higher doses of 7.2 grams daily, anorexia and constipation have been reported. However, gastrointestinal effects of lactoferrin, including epigastric pain, constipation, nausea, and diarrhea, are less common than with other sources of iron such as ferrous sulfate.”

    Lactoferrin · Natural Medicines adverse-effect record, reported in anorexia.

    4 sources cited
    1. 13323. Okada S, Tanaka K, Sato T, et al. Dose-response trial of lactoferrin in patients with chronic hepatitis C. Jpn J Cancer Res 2002;93:1063-9. PubMed
    2. 97788. Abu Hashim H, Foda O, Ghayaty E. Lactoferrin or ferrous salts for iron deficiency anemia in pregnancy: A meta-analysis of randomized trials. Eur J Obstet Gynecol Reprod Biol. 2017;219:45-52. PubMed
    3. 104857. Tarnow-Mordi WO, Abdel-Latif ME, Martin A, et al. The effect of lactoferrin supplementation on death or major morbidity in very low birthweight infants (LIFT): a multicentre, double-blind, randomised controlled trial. Lancet Child Adolesc Health. 2020 Jun PubMed
    4. 104858. ELFIN trial investigators group. Enteral lactoferrin supplementation for very preterm infants: a randomised placebo-controlled trial. Lancet. 2019 Feb 2;393(10170):423-433. doi: 10.1016/S0140-6736(18)32221-9.
  • Yellowing of the skin or eyes Worth acting on Additional detail

    Recorded for Lactoferrin in the same Natural Medicines adverse-effect record shown under A bowel blockage above.

  • Chills / Tiredness Additional detail

    “Orally, at higher doses of 7.2 grams daily, lactoferrin has been reported to cause fatigue and chills.”

    Lactoferrin · Natural Medicines adverse-effect record, reported in fatigue.

    1 source cited
    1. 13323. Okada S, Tanaka K, Sato T, et al. Dose-response trial of lactoferrin in patients with chronic hepatitis C. Jpn J Cancer Res 2002;93:1063-9. PubMed
  • Reduced appetite Additional detail

    Recorded for Lactoferrin in the same Natural Medicines adverse-effect record shown under A bowel blockage above.

  • Constipation / Diarrhea / Nausea Additional detail

    Recorded for Lactoferrin in the same Natural Medicines adverse-effect record shown under A bowel blockage above.

Everything above comes from the Natural Medicines adverse-effect record for Lactoferrin — expand a row for the licensed statement it rests on. We read the ADVERSE REACTIONS section of Tadalafil’s FDA label too, and the two lists don’t meaningfully overlap — which is why no Tadalafil column appears here.

Special populations

Lactoferrin in Pregnancy & Breastfeeding

Pregnancy Likely Safe

When used orally in amounts commonly found in foods. Lactoferrin has Generally Regarded as Safe (GRAS) status in the US.

Pregnancy Possibly Safe

When used orally in medicinal amounts. Lactoferrin has been used with apparent safety during the second or third trimester of pregnancy at doses of up to 250 mg daily for up to 8 weeks. Also, bovine lactoferrin has been used with apparent safety throughout all trimesters of pregnancy at doses of up to 200 mg daily. There is insufficient reliable information available about the safety of intravaginal lactoferrin during pregnancy and lactation; avoid using.

Lactation Likely Safe

When used orally in amounts commonly found in foods. Lactoferrin has Generally Regarded as Safe (GRAS) status in the US. There is insufficient reliable information available about the safety of lactoferrin when used medicinally during lactation; 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 Lactoferrin 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 Lactoferrin 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 Lactoferrin 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 Lactoferrin as Part of a Dietary Supplement Product? Check It for Interactions

We hold 292 real supplement products containing Lactoferrin, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Lactoferrin. Even though Lactoferrin 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 Lactoferrin 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 Lactoferrin
Top half

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

What is Lactoferrin?

  • Iron deficiency and anemia support
  • Immune support
  • Gut health
  • Stomach (H. pylori) infection
  • Acne
  • Diarrhea prevention in infants

Lactoferrin is an iron-binding protein found naturally in milk and other body fluids, and supplements are usually made from cow's milk or rice. It is being studied for immune support, iron levels, gut health, and infections, but the evidence is still limited and mixed for most uses. It is generally well tolerated, but talk with a pharmacist or doctor before starting it.

Protein from milk (colostrum), or made with recombinant technology · Capsules, tablets, powders; also added to some infant formulas and functional foods

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

Lactoferrin: dosing

There is no official standardized dose of lactoferrin, and the right amount can depend on the product, the form, and the reason for use. Doses used in research have varied widely.The best approach is to follow the directions on the product label and not exceed the recommended amount.

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

Read the full Lactoferrin 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 & Lactoferrin

Browse every other medication we’ve checked against Lactoferrin — 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

Lactoferrin References

The 6 references that drive our Lactoferrin 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. Food and Drug Administration, CFSAN/Office of Food Additive Safety. Agency Response Letter GRAS Notice No. GRN 000130. 2003. Available at: http://www.cfsan.fda.gov/~rdb/opa-g130.html (Accessed 29 June 2005).
  2. Okada S, Tanaka K, Sato T, et al. Dose-response trial of lactoferrin in patients with chronic hepatitis C. Jpn J Cancer Res 2002;93:1063-9. PubMed
  3. Abu Hashim H, Foda O, Ghayaty E. Lactoferrin or ferrous salts for iron deficiency anemia in pregnancy: A meta-analysis of randomized trials. Eur J Obstet Gynecol Reprod Biol. 2017;219:45-52. PubMed
  4. Tarnow-Mordi WO, Abdel-Latif ME, Martin A, et al. The effect of lactoferrin supplementation on death or major morbidity in very low birthweight infants (LIFT): a multicentre, double-blind, randomised controlled trial. Lancet Child Adolesc Health. 2020 Jun PubMed
  5. ELFIN trial investigators group. Enteral lactoferrin supplementation for very preterm infants: a randomised placebo-controlled trial. Lancet. 2019 Feb 2;393(10170):423-433. doi: 10.1016/S0140-6736(18)32221-9.
  6. Lepanto MS, Rosa L, Cutone A, Conte MP, Paesano R, Valenti P. Efficacy of lactoferrin oral administration in the treatment of anemia and anemia of inflammation in pregnant and non-pregnant women: An interventional study. Front Immunol. 2018 Sep 21;9:2123. 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 Lactoferrin and Tadalafil Together: Common Questions

Is it safe to take Lactoferrin with Tadalafil?
We do not list a known interaction between Lactoferrin 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.
Does Tadalafil interact with any supplements?
Yes. Tadalafil has documented interactions with 144 supplements in our database — Lactoferrin 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

Still Have a Question About Tadalafil and Lactoferrin?

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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.