Drug & supplement interaction

Methionine + Psyllium (OTC drug)

Psyllium (OTC drug) brand name: Metamucil.

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 Methionine and Psyllium (OTC drug) 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

Methionine and Psyllium (OTC drug)

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 Psyllium (OTC drug) and Methionine 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 Methionine at all — not against Psyllium (OTC drug), 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.

Methionine safety at a glance

Methionine overall Use caution Usually safe in food amounts, but high-dose supplements may cause side effects and should be used with medical guidance.
Pregnancy Likely Safe When used orally in amounts commonly found in food. There is insufficient reliable information available about the safety of methionine in medical doses during... Read the full pregnancy detail
Breastfeeding Likely Safe When used orally in amounts commonly found in food. There is insufficient reliable information available about the safety of methionine in medical doses during... 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 Psyllium (OTC drug) and Methionine? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

What Methionine Itself Has Been Linked To

This is not an interaction — nothing below involves Psyllium (OTC drug). It is the side-effect record for Methionine on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Methionine, this list is the first place to look. One entry is worth acting on rather than waiting out — marked below.

  • Liver problems Worth acting on Additional detail

    “A single dose of 8 grams of methionine has reportedly caused hepatic encephalopathy in patients with cirrhosis. Long-term use of methionine-containing parenteral nutrition solution has been linked to liver toxicity in infants.”

    Methionine · Natural Medicines adverse-effect record, reported in cirrhosis.

    2 sources cited
    1. 9340. Anon. Should methionine be added to paracetamol formulations? Drug Ther Perspect 1997;10:11-3. DOI
    2. 9338. Btaiche IF, Khalidi N. Parenteral nutrition-associated liver complications in children. Pharmacotherapy 2002;22:188-211.. PubMed
  • Mood changes or irritability / Drowsiness / Swelling / Dizziness / Headache Additional detail

    “Orally or intravenously, methionine can cause dizziness, drowsiness, headache, and irritability.

    A case of cerebral edema ultimately leading to death has been reported in a patient receiving methionine 100 mg/kg orally.”

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

    4 sources cited
    1. 9339. Cottington EM, LaMantia C, Stabler SP, et al. Adverse event associated with methionine loading test: a case report. Arterioscler Thromb Vasc Biol 2002;22:1046-50.. PubMed
    2. 9340. Anon. Should methionine be added to paracetamol formulations? Drug Ther Perspect 1997;10:11-3. DOI
    3. 94095. Talukdar R, Murthy HV, Reddy DN. Role of methionine containing antioxidant combination in the management of pain in chronic pancreatitis: a systematic review and meta-analysis. Pancreatology 2015;15(2):136-44. PubMed
    4. 63119. Yaghmai, R., Kashani, A. H., Geraghty, M. T., Okoh, J., Pomper, M., Tangerman, A., Wagner, C., Stabler, S. P., Allen, R. H., Mudd, S. H., and Braverman, N. Progressive cerebral edema associated with high methionine levels and betaine therapy in a patient
  • Low blood pressure Additional detail

    “Orally or intravenously, methionine can cause hypotension. High-dose methionine (75-100 mg/kg daily) may increase plasma concentrations of homocysteine, which is a risk factor for vascular disease. However, a study of patients with type 2 diabetes and a history of cardiovascular disease (CVD) showed that methionine loading did not increase homocysteine concentrations, and that a cause-effect relationship between incr…”

    Methionine · Natural Medicines adverse-effect record, reported in cardiovascular disease (cvd).

    6 sources cited
    1. 9339. Cottington EM, LaMantia C, Stabler SP, et al. Adverse event associated with methionine loading test: a case report. Arterioscler Thromb Vasc Biol 2002;22:1046-50.. PubMed
    2. 9340. Anon. Should methionine be added to paracetamol formulations? Drug Ther Perspect 1997;10:11-3. DOI
    3. 63112. McAuley, D. F., Hanratty, C. G., McGurk, C., Nugent, A. G., and Johnston, G. D. Effect of methionine supplementation on endothelial function, plasma homocysteine, and lipid peroxidation. J.Toxicol.Clin.Toxicol. 1999;37(4):435-440. PubMed
    4. 63114. Hanratty, C. G., McGrath, L. T., McAuley, D. F., Young, I. S., and Johnston, G. D. The effects of oral methionine and homocysteine on endothelial function. Heart 2001;85(3):326-330. PubMed
    5. 63115. Ward, M., McNulty, H., McPartlin, J., Strain, J. J., Weir, D. G., and Scott, J. M. Effect of supplemental methionine on plasma homocysteine concentrations in healthy men: a preliminary study. Int.J.Vitam.Nutr.Res. 2001;71(1):82-86. PubMed
    6. 63110. Smulders, Y. M., Rakic, M., Slaats, E. H., Treskes, M., Sijbrands, E. J., Odekerken, D. A., Stehouwer, C. D., and Silberbusch, J. Fasting and post-methionine homocysteine levels in NIDDM. Determinants and correlations with retinopathy, albuminuria, and c
  • Vomiting Additional detail

    “Orally or intravenously, methionine can cause vomiting.”

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

    2 sources cited
    1. 9339. Cottington EM, LaMantia C, Stabler SP, et al. Adverse event associated with methionine loading test: a case report. Arterioscler Thromb Vasc Biol 2002;22:1046-50.. PubMed
    2. 9340. Anon. Should methionine be added to paracetamol formulations? Drug Ther Perspect 1997;10:11-3. DOI

Everything above comes from the Natural Medicines adverse-effect record for Methionine — expand a row for the licensed statement it rests on. We haven’t matched Psyllium (OTC drug) to its FDA label in our system yet, so we can’t compare its own side-effect list here — the leaflet that comes with your prescription is the authoritative list for Psyllium (OTC drug).

Special populations

Methionine in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Safe

When used orally in amounts commonly found in food. There is insufficient reliable information available about the safety of methionine in medical doses during pregnancy and 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 Methionine or Psyllium (OTC drug)

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Methionine or Psyllium (OTC drug), 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 Psyllium (OTC drug)

This page covers Methionine only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Psyllium (OTC drug) 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 Psyllium (OTC drug) page

“Activated charcoal tops the psyllium (Metamucil) list and is the one entry rated major. Charcoal binds many medicines in the gut and can cut how much of them reaches the body, so pairing it with anything you take by mouth deserves real caution, and I would read that entry before the rest.”

Reviewed by 2 · Jul 18, 2026

Open the Psyllium (OTC drug) interaction page

One more smart check

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

We hold 3,129 real supplement products containing Methionine, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Methionine. Even though Methionine itself has no known interaction with Psyllium (OTC drug), 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 Methionine and Psyllium (OTC drug) 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 Methionine
Top 5%

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

29 days ago today
Medication Psyllium (OTC drug)
Steady interest

#1,649 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 Methionine reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Methionine and Psyllium (OTC drug) 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 Methionine

What is Methionine?

  • Acetaminophen (Tylenol) overdose support
  • Liver health
  • Urinary tract acidification
  • Supporting protein and nutritional needs
  • General antioxidant support

Methionine is an essential amino acid that your body needs for protein building and many basic chemical reactions. Most people get enough from a normal diet, and supplements are generally not needed unless directed by a healthcare provider. High doses can cause side effects, so talk to your pharmacist or doctor before using methionine supplements.

Amino acid (made through fermentation or chemical synthesis for supplements) · Capsules, tablets, powder, and as part of amino acid blends; also given intravenously in hospitals

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

Methionine: dosing

There is no single standard supplement dose of methionine for general health, and most healthy people do not need extra beyond what they eat. Your body's daily methionine needs are normally met through a balanced diet.If a product is used, follow the directions on the label and do not take more than recommended.

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

Read the full Methionine monograph & all interactions
Medication

About Psyllium

What Is Psyllium Used For?

Brand name: Metamucil

Psyllium is used to treat occasional constipation and help restore regularity. Most products indicate that a bowel movement generally occurs within 12 to 72 hours of taking a dose.

This applies to psyllium capsule products such as Best Choice, Careone, fiber laxative, meijer fiber laxative, Premier Value Fiber, and Publix, as well as oral powder products including Best Choice Fiber Therapy, Careone, Daily Fiber, Dr. Fibra, meijer fiber therapy, and Meijer Natural Daily Fiber Sugar Free.

See full Psyllium drug information
Keep checking

Other Drugs & Methionine

Browse every other medication we’ve checked against Methionine — 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
2,829 No interaction
No interaction 2,829 drugs checked — show the list

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

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Methionine list.

See the full Methionine interactions page
See every supplement checked against Psyllium (OTC drug), ranked by severity
Evidence & sources

Methionine References

The 12 references that drive our Methionine 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. La Vecchia C, Negri E, Franceschi S, Decarli A. Case-control study on influence of methionine, nitrite, and salt on gastric carcinogenesis in northern Italy. Nutr Cancer 1997;27:65-8. PubMed
  2. Btaiche IF, Khalidi N. Parenteral nutrition-associated liver complications in children. Pharmacotherapy 2002;22:188-211.. PubMed
  3. Cottington EM, LaMantia C, Stabler SP, et al. Adverse event associated with methionine loading test: a case report. Arterioscler Thromb Vasc Biol 2002;22:1046-50.. PubMed
  4. Anon. Should methionine be added to paracetamol formulations? Drug Ther Perspect 1997;10:11-3. DOI
  5. Smulders, Y. M., Rakic, M., Slaats, E. H., Treskes, M., Sijbrands, E. J., Odekerken, D. A., Stehouwer, C. D., and Silberbusch, J. Fasting and post-methionine homocysteine levels in NIDDM. Determinants and correlations with retinopathy, albuminuria, and c
  6. McAuley, D. F., Hanratty, C. G., McGurk, C., Nugent, A. G., and Johnston, G. D. Effect of methionine supplementation on endothelial function, plasma homocysteine, and lipid peroxidation. J.Toxicol.Clin.Toxicol. 1999;37(4):435-440. PubMed
  7. Hanratty, C. G., McGrath, L. T., McAuley, D. F., Young, I. S., and Johnston, G. D. The effects of oral methionine and homocysteine on endothelial function. Heart 2001;85(3):326-330. PubMed
  8. Ward, M., McNulty, H., McPartlin, J., Strain, J. J., Weir, D. G., and Scott, J. M. Effect of supplemental methionine on plasma homocysteine concentrations in healthy men: a preliminary study. Int.J.Vitam.Nutr.Res. 2001;71(1):82-86. PubMed
  9. Yaghmai, R., Kashani, A. H., Geraghty, M. T., Okoh, J., Pomper, M., Tangerman, A., Wagner, C., Stabler, S. P., Allen, R. H., Mudd, S. H., and Braverman, N. Progressive cerebral edema associated with high methionine levels and betaine therapy in a patient
  10. Talukdar R, Murthy HV, Reddy DN. Role of methionine containing antioxidant combination in the management of pain in chronic pancreatitis: a systematic review and meta-analysis. Pancreatology 2015;15(2):136-44. PubMed
  11. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: The National Academies Press, 2005. Available at: https://doi.org/10.17226 DOI
  12. Khairan P, Sobue T, Eshak ES, et al. Association of B Vitamins and Methionine Intake with the Risk of Gastric Cancer: The Japan Public Health Center-based Prospective Study. Cancer Prev Res (Phila) 2022;15(2):101-110. 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 Methionine and Psyllium (OTC drug) Together: Common Questions

Is it safe to take Methionine with Psyllium (OTC drug)?
We do not list a known interaction between Methionine and Psyllium (OTC drug). 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 Psyllium (OTC drug) interact with any supplements?
Yes. Psyllium (OTC drug) has documented interactions with 17 supplements in our database — Methionine is not one of them. The Psyllium (OTC drug) 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

Methionine monograph Uses, safety profile, and every drug interaction in one place Psyllium drug information The full plain-English guide to this medication Psyllium (OTC drug) supplement interactions Every supplement checked against Psyllium (OTC drug), 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 12 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Psyllium (OTC drug) and Methionine?

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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.