No known drug interactions for the matched ingredients — not a guarantee none exist. Check your meds →
Dietary supplement

L-Methionine 500 mg Ingredients & Drug Interactions

by Swanson

L-Methionine 500 mg label
See full label image
Capsule Category: Amino Acid/protein
No known interaction
Clinical methodology reviewed by · Updated Sep 9, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking L-Methionine 500 mg against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line No known interaction

L-Methionine 500 mg is a dietary supplement by Swanson with 1 active ingredient. Its ingredients are commonly taken for acetaminophen (tylenol) overdose support, liver health, urinary tract acidification.We don’t currently list a known drug interaction for its mapped ingredients — but that doesn’t guarantee none exist, so always confirm with your pharmacist.

Jump to a section

HelloPharmacist Scorecard of L-Methionine 500 mg by Swanson

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: L-methionine, a sulfur-containing amino acid your body uses to make proteins and other compounds. The rest is inert filler — rice flour, gelatin, magnesium stearate, and silica — to form and stabilize the capsule.

Does it work?

Not established
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not established

The graded evidence we hold for these ingredients covers different conditions than the ones this product is marketed for, so there's no established rating for its stated use — see Methionine's own graded uses on its monograph.

Why this rating?
  • The label markets this product for: promotes healthy liver function and antioxidant enzymes.
  • We looked for evidence on: Acetaminophen poisoning, Liver detoxification, Hepatic function, Drug metabolism support.
  • The closest evidence on file: Methionine is rated "Insufficient Reliable Evidence To Rate" for Acetaminophen poisoning (Natural Medicines).

The evidence on L-methionine is patchy. It's rated possibly effective for reducing the risk of neural tube birth defects (like spina bifida), but we don't have enough reliable data to rate it for acetaminophen poisoning, hay fever, asthma, or colorectal cancer.

If you're considering it for a specific reason, ask your pharmacist whether that use is supported.

The evidence, ingredient by ingredient Methionine

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

When you eat methionine in food amounts, it's well tolerated. At supplement doses, though, the safety picture changes.

High-dose supplements may cause dizziness, drowsiness, low blood pressure (hypotension), irritability, vomiting, headache, or elevated homocysteine (a risk factor for heart disease). Rare serious effects — cerebral swelling or liver encephalopathy — have been reported.

During pregnancy and breastfeeding, food amounts are fine, but supplement doses haven't been proven safe. Use high-dose supplements only under medical guidance.

Side effects, ingredient by ingredient Methionine

Meds to double-check

No known interactions
Known Interaction Concern · database check
No known interactions

No medication interactions are currently documented for the matched ingredients — that isn't a guarantee none exist.

Why this rating?
  • None of the 1 matched ingredient has a documented medication interaction on file.

No interactions are documented in our data for L-methionine. Still, check your exact medications with the search tool on this page before you start.

The bottom line

Scorecard at a glanceFully disclosed formula with no established evidence rating for its marketed use. No medication interactions are currently documented, and safety information is well characterized.

L-methionine as a food-level supplement is generally well tolerated, but high doses need careful medical oversight — especially if you're pregnant, breastfeeding, or at risk for heart disease. Talk to your pharmacist about why you're taking it and whether this dose is right for you.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Jun 20, 2024.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about L-Methionine 500 mg, straight from the product label.

Brand Swanson
Barcode (UPC) 087614111216
Net contents 30 Capsule(s)
Market status On market
Date entered into DSLD Jun 20, 2024
DSLD ID 308438
Product type Amino Acid/protein
Supplement form Capsule
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years)
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for L-Methionine 500 mg by Swanson, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
30
UPC/BARCODE
087614111216
IngredientAmount% DV
L-Methionine500 mg--

Other ingredients: Rice Flour, Gelatin, Magnesium Stearate, Silica

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Formulation

Promotes healthy liver function Activates endogenous antioxidant enzymes

Antioxidant support

Formula

Essential amino acid

L-Methionine 500 mg per capsule

General Statements

Science-Backed Quality Since 1969

Suggested/Recommended/Usage/Directions

Suggested use: As a dietary supplement, take one capsule per day with food and water. Do not exceed recommended dosage.

Precautions

Warning: For adults only. Keep out of reach of children.

Consult with your healthcare provider before use if you are pregnant or nursing, if you are taking medication or if you have a medical condition, such as liver disease, kidney disease, elevated homocysteine or cancer.

Do not exceed recommended dosage. Do not use if seal is broken.

Storage

Store in a cool, dry place.

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

FDA Statement of Identity

Dietary Supplement

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

L-Methionine 500 mg by Swanson label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

L-Methionine 500 mg label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in L-Methionine 500 mg by Swanson

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Servings per container30 Amounts shown are per serving.

L-Methionine

No known
interactions
500 mg per serving

Methionine is an essential amino acid that your body needs for protein building and many basic chemical reactions. Most people get enough from a norma...

L-Methionine monograph & interactions

Other (inactive) ingredients: Rice Flour, Gelatin, Magnesium Stearate, Silica. These complete the product’s ingredient list but are not active constituents.

Interaction report

L-Methionine 500 mg by Swanson Drug Interactions

We don’t currently list any known drug interactions for the mapped ingredients in L-Methionine 500 mg. This doesn’t guarantee none exist — always confirm with your pharmacist before combining a supplement with your medications.

The maker

Brand information

Manufacturer and brand details for L-Methionine 500 mg, from the product label.

Swanson

See all Swanson products
Name
Swanson Health Products
City
Fargo
State
ND
ZipCode
58104
Phone Number
1-800-437-4148
Web Address
swanson.com
Pharmacist Counseling Corner

L-Methionine 500 mg by Swanson: Common Questions

Does L-Methionine 500 mg by Swanson interact with any medications?
We do not currently list a known interaction for the mapped ingredients in L-Methionine 500 mg. This does not guarantee none exist, so confirm with your pharmacist.
How can one product interact with so many drugs?
L-Methionine 500 mg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Is L-methionine safe during pregnancy?
Food amounts are fine. But supplement doses — like this 500 mg capsule — haven't been proven safe during pregnancy. Talk with your doctor or pharmacist about whether you should take it.
Can L-methionine cause side effects?
At food-level amounts, no — it's well tolerated. At supplement doses, you might experience dizziness, drowsiness, low blood pressure, irritability, vomiting, or headache. High-dose supplements can also raise homocysteine, a risk factor for heart and blood vessel disease. Rare serious effects like brain swelling have been reported.
Does L-methionine actually work for anything?
It's rated possibly effective for preventing neural tube birth defects. For acetaminophen poisoning, hay fever, asthma, and colorectal cancer, we don't have enough reliable evidence to say. Your pharmacist can help you figure out whether this supplement makes sense for what you're trying to do.
Is this safe if I have heart disease?
High-dose methionine can raise homocysteine, a risk factor for vascular disease. If you have heart disease or a history of it, talk with your doctor before taking this supplement.
What are the inactive ingredients?
Rice flour, gelatin, magnesium stearate, and silica — standard capsule fillers and binders with no active role.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Not sure if L-Methionine 500 mg is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

L-Methionine 500 mg label
Go deeper

The Full Monographs Behind L-Methionine 500 mg’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Methionine

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 no...

Read the full Methionine monograph →
Sources

Sources & How We Checked

L-Methionine 500 mg's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 12 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Methionine 12 references
  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

See these in context on the Methionine monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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