L-Methionine

Evidence status

Limited evidence to recommend for any consumer outcome yet.

5 papers · 1 claim · 9 outcomes scored

Outcomes

What l-methionine actually does, by outcome

Each row is one outcome with effect size, evidence base, the dose that worked in trials, and time to first effect. Magnitude tiers come from native-unit MCID where available, Cohen's d otherwise.

Outcome Effect size Evidence Dose Weeks Rank

Lower homocysteine levels Early negative signal

Clears a vessel-irritating byproduct that builds when nutrient recycling falls behind.

1 RCT n=51 2000–4000 mg 8–12 wk

19407666

moderate

1 RCT n=51

2000–4000 mg

8–12 wk

—

Outcome	Effect	Evidence	Dose	Weeks	Rank
Lower homocysteine levels Early negative signal	moderate	1 RCT n=51	2000–4000 mg	8–12 wk	—

Risk profile

Adverse events and known drug interactions

Safety events

case_report_hepatotoxicity_related_to_methionine_load severe

homocysteine_increase

adverse events (any)

sexual dysfunction

insomnia

appetite loss

Drug interactions

Acetaminophen major increases toxicity

Sources

Generated August 14, 2026

L-Methionine

What l-methionine actually does, by outcome

Adverse events and known drug interactions

More evidence for L-Methionine

The Sulfur Switch: Why an Essential Amino Acid Sometimes Works Best in Reverse

Garlic

Vitamin B12

Vitamin B2

Vitamin B9 / Folate

Garlic for Cardiovascular Health: A Systematic Evidence Review

L-Methionine

More evidence for L-Methionine

NewThe Sulfur Switch: Why an Essential Amino Acid Sometimes Works Best in Reverse

NewGarlic

NewVitamin B12

NewVitamin B2

NewVitamin B9 / Folate

NewGarlic for Cardiovascular Health: A Systematic Evidence Review

The Sulfur Switch: Why an Essential Amino Acid Sometimes Works Best in Reverse

Garlic

Vitamin B12

Vitamin B2

Vitamin B9 / Folate

Garlic for Cardiovascular Health: A Systematic Evidence Review