Supplement evidence

104 / 575Performance

L-carnitine

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The short answer

Treats primary carnitine deficiency and is studied for selected dialysis, metabolic, and exercise outcomes.

Evidence and scope: Conditional or population-specific
This status does not grade the ingredient for every goal, outcome, or person.
Important limitation: Benefit depends on the population, formulation, baseline status, and objective; results should not be generalized.
Before deciding: Key concern: Warfarin, thyroid hormone, seizures, kidney disease, and TMAO concerns require review.

01 / PRACTICAL GUIDE

Dose, absorption, and combinations

These are indication-specific reference or studied ranges—not a personalized prescription. Start with the objective, then check the form, label, medicines, and health conditions.

Reference range by objective

Confirmed deficiencyClinician-directed

Reference or studied range—not a personalized prescription. The product label or a clinician may specify a different dose.

Dose source ↗

Sports performance1–3 g/day in many trials

Reference or studied range—not a personalized prescription. The product label or a clinician may specify a different dose.

Dose source ↗

More is not automatically better. A clinician or product label may specify a different amount.

Absorption / solubilityWater-soluble

Water-soluble or readily water-dispersible. This does not mean excess is always harmless.

How it is commonly taken

Take with meals; chronic muscle uptake may be enhanced with carbohydrate.

Do not combine casually

Warfarin, thyroid hormone, seizures, kidney disease, and TMAO concerns require review.

Dose and use source ↗

Dose and use links lead to primary or official source material. Search links are discovery tools, not proof that every returned paper applies.

02 / EVIDENCE

What the research says

We keep supportive, mixed, negative, safety, and contextual findings together. The headline never replaces the underlying papers.

2research papers in this ledger

6unique primary studies represented

3,265unique participants represented

These are audited counts for this JIVANA collection, not search-result totals. Participants are counted once when multiple papers use the same cohort; review papers are not added again to participant totals.

Open the research timelineResearch timeline

Entries are ordered by publication year. A study period appears only when the source reports it.

2022

Safety signalPMID 35366920

L-carnitine and atherosclerosis progression in metabolic syndrome

Total plaque-volume change did not differ, while carotid stenosis increased more with L-carnitine. This safety signal and uncertain TMAO implications argue against cardiovascular self-treatment.

Published: 2022Duration: 6 monthsn=157 participants

Study design and methods

Design: Phase 2 randomized, double-blind, placebo-controlled two-center trial
Population: 157 adults with metabolic syndrome and measurable carotid plaque
Intervention: L-carnitine 2 g/day versus placebo
Outcome: Carotid total plaque volume and stenosis

Open research record ↗

2014

Does not support the tested claimPMID 25044037

L-carnitine dosing after acute myocardial infarction

No dose significantly reduced mortality, heart failure, unstable angina, or reinfarction. The review does not support using L-carnitine as routine secondary prevention after myocardial infarction.

Published: 2014n=3,108 participants5 primary studies represented

Study design and methods

Design: Systematic review and meta-analysis of 5 controlled trials
Population: 3,108 adults after acute myocardial infarction
Intervention: Oral L-carnitine maintenance doses of 2–6 g/day versus control
Outcome: All-cause mortality, heart failure, unstable angina, and recurrent myocardial infarction

Open research record ↗

Unscreened discovery appendix—not evidence597 candidate publicationsSearch run: Aug 21, 2026

Complete for the displayed PubMed query at the search timestamp—not for all databases or every possible synonym. Candidates can be irrelevant, duplicate the same study, or report negative findings. They are never summed as evidence or participants until screened.

03 / SOURCES

Start with the source material

Official evidence overviewPubMed bounded human-evidence search Live PubMed discovery searchNational Library of Medicine

The live search is for discovery only. Search-result counts change and are not included in the audited totals above.

Recent PubMed discovery recordsDirect links to the first 12 records returned by the reproducible search. These are discovery candidates—not reviewed summaries or a count of supportive findings.

04 / EXPERT CONTEXT

Expert context—not evidence

Expert positions are dated context—not scientific evidence. They never raise the evidence status or become consensus by repetition.

No direct, source-verified endorsement is currently recorded. Research authorship or discussion alone is not treated as endorsement.