Amino Acid
L-Methionine
Also known as: Methionine
Essential sulfur amino acid. Precursor to cysteine, taurine, and SAM-e.
Last reviewed June 2026 · Evidence graded from peer-reviewed research, not editorial opinion. Educational only — not medical advice.
Every L-Methionine product we have scored
| # | Product | Score | Per serving |
|---|---|---|---|
| 1 | Pure Encapsulations L-Methionine | 87 A | $0.35 |
| 2 | NOW Foods L-Methionine | 86 A- | $0.30 |
| 3 | Thorne Amino Complex - Travel Packs - Berry | 85 A- | $1.20 |
| 4 | Thorne Amino Complex - Travel Packs - Lemon | 85 A- | $1.20 |
| 5 | Thorne Amino Complex - Berry | 84 A- | $1.47 |
| 6 | Thorne Amino Complex - Lemon | 84 A- | $1.47 |
| 7 | Pure Encapsulations UltraDetox 10-Day Pure Pack | 83 A- | $7.55 |
| 8 | Pure Encapsulations Lipotropic Detox | 81 A- | $0.57 |
| 9 | Pure Encapsulations Essential Aminos | 81 A- | $0.31 |
| 10 | Thorne Amino Complex | 80 A- | $1.20 |
| 11 | Pure Encapsulations DIM Detox | 80 A- | $1.93 |
| 12 | Jarrow Formulas SAMe - 200mg | 80 A- | $0.78 |
Scored on dose accuracy, form, label transparency and third-party testing. Per-serving cost is list price divided by servings per container. No brand pays to be listed or ranked.
Common questions
How much L-Methionine should I take?
The typical range is 500-1500mg daily. Moderate duration
When should I take L-Methionine?
Between meals. Optional.
Which form of L-Methionine is best?
Capsules — Standard. Other forms in the catalog: Powder.
Is L-Methionine safe?
Commonly reported: GI upset. Serious warnings: May raise homocysteine (need B vitamins). Safe at moderate doses
Which L-Methionine supplement scores highest?
Pure Encapsulations L-Methionine, at 87/100. Scored on dose accuracy, form, label transparency and third-party testing — no brand pays to be listed or ranked.
Primary uses
- Sulfur source
- SAM-e precursor
- Liver support
- Detox
What systematic reviews concluded
Outcomes that systematic reviews of L-Methionine reached a verdict on: 1 with a benefit, 1 with no effect, 3 unclear. Each is quoted from a review and linked to it on PubMed. How these were read.
Reviews found a benefit (1)
“there was a significant difference in the pruritus score” PMID 25774783
Reviews found no effect (1)
“An analysis of the adverse events and long-term prognosis also indicated no significant differences between the SAMe and the placebo groups.” PMID 25774783
Not enough to say: depressive symptoms (as same augmentation in mdd); liver function markers; alcoholic liver disease outcomes.
How it works
- Precursor to cysteine and taurine
- Methyl donor (as SAM-e)
- Antioxidant support
Dosage
- Typical range
- 500-1500mg daily
- Timing
- Between meals
- With food
- Optional
- Duration
- Moderate duration
- Special populations
- Liver support, sulfur support
Forms
- Capsules
- Powder
Safety
Common side effects
- GI upset
Contraindications
- High homocysteine
- Schizophrenia
Products containing L-Methionine
Top-scoring supplements in our catalog that list L-Methionine on the label. Each product is graded on Formulate's ingredient-level rubric — dose accuracy, form, transparency, and third-party testing.
Evidence notes
Essential amino acid
Grade B: Some human trials support key claims; further confirmation needed.
Related in Amino Acid
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Medical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider. Individual needs and risks vary — consult a professional before starting, stopping, or combining supplements, especially if you are pregnant or nursing, taking medication, or managing a health condition.