MetabolicSmall molecule

L-Carnitine

Levocarnitine, an endogenous carnitine compound

Levocarnitine has prescription deficiency indications; research-market athletic injections are not the same formulation.

What does it do?

Carnitine deficiency

Approved use

CARNITOR injection is labeled for specified metabolic disorders and prevention/treatment of deficiency in dialysis patients. This does not establish a performance benefit.21

Deficiency and dialysis

Study

Defined clinical settings differ from weight-loss injections.2

Molecular information

4

Amino-acid sequence

Not applicable: this compound is not a single peptide.

LengthNonpeptide
Molecular weight · Da161.20 Da
Molecular formulaC7H15NO34

Hydrochloride and tartrate salts have different composition and mass.

Pharmacokinetics

Human data
Reported half-life17.4 hours — apparent terminal half-life21
Route / formulationIntravenous CARNITOR; slow 3-minute bolus
Illustrative half-life model for L-Carnitine: Human study / labelNormalized terminal-phase decline, not measured blood concentration or effect duration. Five half-lives leaves 3.125%. 0%50%100%017.4 h34.8 h2.18 d2.9 d3.63 d1 half-life
50%of reference level

Illustrative model using reported human data.

About 3% remaining after 3.63 d

Five half-lives in this simplified model. This is not a prediction of when effects stop.

About this estimate

The label uses a two-compartment model. This illustration models only terminal decline; it is not the full two-compartment curve. It does not establish subcutaneous or intramuscular kinetics.

Population: Human label PK; concentrations uncorrected for endogenous levocarnitine

100 × 2−time / half-life. Time zero is a reference level, not the moment of administration. Absorption, repeated dosing, metabolites and clinical effects are not modeled. Five half-lives leaves 3.125%, not zero. This curve cannot determine a dosing interval.

What to expect

Study outcomes

A recent exercise trial was negative

The 2025 placebo-controlled crossover study did not find improved CrossFit performance after acute L-carnitine supplementation. It does not evaluate injectable use.1

Route-specific clinical research

A dialysis trial compared 500 mg orally three times daily with 20 mg/kg IV after dialysis for 24 weeks. Its anemia findings cannot establish fat-loss or performance benefit.2

Reported timelines

Reference & community

Injection: days 1–7

Deficiency correction differs from subjective benefit.22

Weeks 2–12+

Source energy/recovery/composition timelines vary by form and indication.22

These are reported timelines, not a prediction of your response.

Doses & schedules

13 rows
Route

Scroll to compare all columns →

One row for each documented route and dose or dose range
RouteDoseFrequencyGoal / evidenceDurationReferences
Oral500 mgThree times dailyRenal anemia route comparisonMaintenance-hemodialysis patientsHuman study24 weeks2
IVIntravenous20 mg/kgAfter dialysisRenal anemia route comparisonMaintenance-hemodialysis patientsHuman study24 weeks2
IV50 mg/kg/dayDivided doses or continuousCarnitine deficiencyReference reportOngoing for deficiency; 8-12 weeks for performance22
IVIV - Slow push10-20 mg/kgPost-dialysisHemodialysis supportReference reportOngoing for deficiency; 8-12 weeks for performance22
SubQSubcutaneous500-1500 mg1-3x weeklyFat metabolism / PerformanceReference reportOngoing for deficiency; 8-12 weeks for performance22
IMIntramuscular500-1500 mg1-3x weeklyFat metabolism / PerformanceReference reportOngoing for deficiency; 8-12 weeks for performance22
IVIV - InfusionUp to 300 mg/kg/dayDivided or continuousCritical illnessReference reportOngoing for deficiency; 8-12 weeks for performance22
Oral500-1000 mg1-2x dailyGeneral wellness / EnergyReference report12-24 weeks typical; ongoing for maintenance22
OralOral - Empty stomach2000 mg1-2x dailyWeight managementReference report12-24 weeks typical; ongoing for maintenance22
OralOral - Before exercise2000-3000 mg1x dailyExercise performance/recovery (LCLT)Reference report12-24 weeks typical; ongoing for maintenance22
Oral500-2000 mg1-2x dailyCognitive support (ALCAR)Reference report12-24 weeks typical; ongoing for maintenance22
Oral2000 mg1x dailyMale fertilityReference report12-24 weeks typical; ongoing for maintenance22
OralOral - With meals1000-2000 mg1-2x dailyCardiovascular supportReference report12-24 weeks typical; ongoing for maintenance22

Study and label doses retain their study context. Reference reports are unvalidated practices, not personal treatment instructions. Ranges remain ranges; escalation stages are labeled.

Cycles & timing

Reference reports22

Reported use periods and breaks. These do not establish a safe cycle or prove that breaks prevent tolerance.

Injectable

Use period
Ongoing for deficiency; 8-12 weeks for performance
Break
Not typically required
Reported timing

Any time; before exercise for performance goals

Oral

Use period
12-24 weeks typical; ongoing for maintenance
Break
Not typically required; some cycle 8 weeks on/4 weeks off
Reported timing

Empty stomach or 30-60 min before exercise

Side effects & safety

Seizure reports

Seizures have been reported with oral and IV levocarnitine, including increased frequency or severity in people with prior seizures.

3

Serious hypersensitivity

Anaphylaxis, airway swelling and bronchospasm have been reported, mostly in dialysis patients.

3

Additional reported cautions

Reference reports22

Adverse effects

GI upset, odor, injection discomfort; thyroid antagonism and renal TMA/TMAO concerns.

Stop symptoms

Allergy, persistent GI symptoms, weakness/seizure, worsening thyroid or cardiovascular symptoms.

Not a complete safety screen. Discuss health decisions with a qualified clinician.

Combinations & interactions

8 entries

Check cautions and reported pairings. A compatibility claim does not establish that a combination is safe.

Thyroid hormones

Caution reported

May antagonize hormone action.22

Reference report · Pep-Pedia label: Use Caution

Warfarin

Caution reported

Potential INR increase.22

Reference report · Pep-Pedia label: Monitor Combination

Acenocoumarol

Caution reported

Potential anticoagulant potentiation.22

Reference report · Pep-Pedia label: Monitor Combination

NAD+

Unverified pairing

Theoretical energy complement.22

Reference report · Pep-Pedia label: Synergistic

CoQ10

Unverified pairing

Context-specific mitochondrial research.22

Reference report · Evidence context: Synergistic

Alpha-lipoic acid

Unverified pairing

Proposed complement.22

Reference report · Pep-Pedia label: Synergistic

Omega-3 fatty acids

Unverified pairing

Proposed metabolic complement.22

Reference report · Pep-Pedia label: Synergistic

BPC-157

Unverified pairing

Combination untested.22

Reference report · Pep-Pedia label: Compatible

Reconstitution

Marketed solution is already liquid

The checked prescription product is an IV-only aqueous solution; bacteriostatic-water reconstitution does not apply.3

Formulation matters

Research-market SC or IM mixtures are not interchangeable with the checked IV label.3

Reference preparation details

Reported handling information, not a validated formulation or instruction to prepare an injectable product.

Injectable

The source describes a ready-made sterile injectable solution.

Form
Source describes a prepared product
Reported parameters
It mentions normal saline for IV dilution, not powder reconstitution.

Oral

The source distinguishes capsules, tablets and powders across different carnitine forms.

Form
Source describes a prepared product
Reported parameters
Reported powder carriers: drinking water or juice.
22

Appearance & documentation

Appearance and a purity certificate cannot establish sterility, identity, or suitability for injection.

Reported appearanceClear, Colorless SolutionReported appearanceProper PackagingReported variationSlight Yellow TintReported concernCloudy or ParticulateReported concernDamaged Seal
22

Available forms

Prescription IV solution

1 g/5 mL or 4 g/20 mL single-dose vials, both 200 mg/mL. These are liquid prescription presentations, not research powders.3

Packaging examples, not a market survey. Approved and research products are not interchangeable.

Storage after mixing

Reconstituted research vials

No applicable mixing data

The available sources describe prepared products or do not establish a reconstitution method.22

Storage notes

22
Injectable

Room temperature unopened; refrigerate after opening

Oral

Room temperature, cool dry place

Storage depends on the formulation, diluent, container, and handling. Follow the specific product label or pharmacist’s instructions.

Evidence limits

View findings →

Research-market product identity, purity and formulation cannot be established from a publication.1

5 distinct primary sources or abstracts checked. Evidence may concern a parent compound, individual blend ingredient, animal, or cell model; it does not necessarily establish a benefit for this exact product.

Evidence definitions →

Research findings

Human trials

Source context

Source compatibility labels and '100% bioavailability' claims cannot be generalized to all injection routes.

Compound identity & other names

A nutrient and prescription drug for defined deficiency settings. Oral supplementation, intravenous clinical therapy and research-market injections have different evidence and exposure.

Levocarnitine has prescription deficiency indications; research-market athletic injections are not the same formulation.

Levocarnitine, R-enantiomer inner salt4

How it may work

Mitochondrial fatty-acid shuttling; ALCAR, LCLT and propionyl-carnitine findings are formulation-specific.22

A recent exercise trial was negative

The 2025 placebo-controlled crossover study did not find improved CrossFit performance after acute L-carnitine supplementation. It does not evaluate injectable use.

1

Route-specific clinical research

A dialysis trial compared 500 mg orally three times daily with 20 mg/kg IV after dialysis for 24 weeks. Its anemia findings cannot establish fat-loss or performance benefit.

2

Research areas and evidence gaps

Carnitine deficiency. CARNITOR injection is labeled for specified metabolic disorders and prevention/treatment of deficiency in dialysis patients. This does not establish a performance benefit.21

Deficiency and dialysis research. Defined clinical settings differ from weight-loss injections.2

  • Research-market product identity, purity and formulation cannot be established from a publication.

Additional uses listed by Pep-Pedia

Deficiency and dialysis. Approved product/route-specific replacement.22

Weight and energy. Modest oral trial effects; not proof of injectable fat loss.22

Heart and circulation. Cardiac/PAD studies vary by formulation.22

Cognition, exercise and fertility. ALCAR, LCLT and sperm-parameter research; not interchangeable outcomes.22

Community reports Unvalidated

Performance discussions as described by Pep-Pedia.5

No representative survey, independently verified products, or controlled outcomes.

Search coverage and review status

The targeted check identified relevant additional literature or current regulatory information; checked findings are separated from retained bibliography-only references.

Checked
2026-10-12
Search
levocarnitine 2025 2026 randomized trial site:pubmed.ncbi.nlm.nih.gov
Catalog
Pep-Pedia ↗ · 14 listed references retained
  • Targeted search, not an exhaustive systematic review.
  • Bibliography-only entries are retained for traceability and are not treated as verified findings.

AI-prepared summaries. Independent medical editorial review is pending.

Community poll 10 topics · Pep-Pedia snapshot

Voluntary, unverified reports. These percentages do not measure effectiveness or safety.

Primary goal

Fat loss86%
Other: Stamina5%
Muscle growth5%
General wellness5%

Number of responses to this question: not disclosed.

Source & limitations

The source displays “264 responses” for this profile. This is not a confirmed participant count or a denominator for individual questions.

  • Voluntary self-reports from Pep-Pedia visitors; identity, treatment, outcomes and timing are unverified. These data are not efficacy or safety estimates.
  • The source displays a profile-wide response label, not a confirmed unique participant count. It stays unchanged across questions. Question-specific denominators and absolute option counts are not exposed.
  • Only the top five categories are displayed for some questions. Extra categories are retained as an undisplayed-category count; their labels and percentages are unavailable.
  • Displayed percentages are rounded. They may not total 100%, especially where categories are hidden.
  • This is a dated snapshot, not a live survey or current recommendation.

References

Original sources and review status. Open a reference to read its summary.

22 sources

1Acute L-Carnitine Supplementation Does Not Improve CrossFit PerformanceTrial · 2025 · pubmed.ncbi.nlm.nih.govAbstract checked
AI-PREPARED SUMMARY

2025 randomized crossover trial did not find an acute performance benefit from oral supplementation.

A recent exercise trial was negative

The 2025 placebo-controlled crossover study did not find improved CrossFit performance after acute L-carnitine supplementation. It does not evaluate injectable use.

Additional research · Checked 2026-10-12

Original source
2Intravenous versus oral levocarnitine in maintenance hemodialysisTrial · 2025 · pubmed.ncbi.nlm.nih.govAbstract checked
AI-PREPARED SUMMARY

2025 trial compared oral and IV routes in dialysis patients over 24 weeks; IV treatment showed larger improvements in measured hematologic outcomes.

Route-specific clinical research

A dialysis trial compared 500 mg orally three times daily with 20 mg/kg IV after dialysis for 24 weeks. Its anemia findings cannot establish fat-loss or performance benefit.

Additional research · Checked 2026-10-12

Original source
3Levocarnitine Injection USP — American Regent labelRegulator · 2024 · dailymed.nlm.nih.govPrimary source checked
AI-PREPARED SUMMARY

Ready-to-use IV solution, 200 mg/mL, for specified deficiency indications. Label lists seizures, severe hypersensitivity and a warfarin INR interaction.

Additional research · Checked 2026-10-12

Original source
4PubChem: Levocarnitine, R-enantiomer inner saltRegistry · 2026 · pubchem.ncbi.nlm.nih.govPrimary source checked
AI-PREPARED SUMMARY

Chemical registry identity, molecular formula and molecular weight; not clinical efficacy evidence.

Additional research · Checked 2026-10-12

Original source
5Pep-Pedia: L-Carnitine — community referenceCommunity · 2026 · pep-pedia.orgCommunity source checked
AI-PREPARED SUMMARY

Accessed October 12, 2026. Secondary descriptions and bibliography; community schedules are unvalidated reports, not recommendations.

Original source
6Weight Loss Meta-Analysis (2020)Review · 2020 · doi.orgPep-Pedia report · Primary source not checked
AI-PREPARED SUMMARY

Pep-Pedia reports: The meta-analysis reported modest pooled changes: weight −1.21 kg, BMI −0.24 kg/m² and fat mass −2.08 kg.

Reported population / model
37 RCTs

Reported study details
2,292 participants · Various doses · Significant weight reduction

Reported by Pep-Pedia; the linked publication, design, doses and result have not been independently verified here.

Read the Pep-Pedia report ↗

Pep-Pedia reference card; original summary of its reported findings · Checked 2026-10-12

Listed study
7Cardiovascular Secondary Prevention (2013)Research reference · 2013 · doi.orgPep-Pedia report · Primary source not checked
AI-PREPARED SUMMARY

Pep-Pedia reports: Pooled older cardiac trials associated supplementation with lower mortality, arrhythmia and angina; trial quality and applicability require examination.

Reported population / model
13 controlled trials

Reported study details
3,629 participants · Meta-analysis · Mortality outcomes

Reported by Pep-Pedia; the linked publication, design, doses and result have not been independently verified here.

Read the Pep-Pedia report ↗

Pep-Pedia reference card; original summary of its reported findings · Checked 2026-10-12

Listed study
8Exercise Recovery LCLT Study (2021)Research reference · 2021 · doi.orgPep-Pedia report · Primary source not checked
AI-PREPARED SUMMARY

Pep-Pedia reports: A five-week placebo-controlled study reported less soreness and lower creatine kinase after strenuous exercise with L-carnitine L-tartrate.

Reported population / model
73 participants

Reported study details
2g/day · 5 weeks · Double-blind placebo-controlled

Reported by Pep-Pedia; the linked publication, design, doses and result have not been independently verified here.

Read the Pep-Pedia report ↗

Pep-Pedia reference card; original summary of its reported findings · Checked 2026-10-12

Listed study
9Male Fertility Parameters Study (2022)Research reference · 2022 · doi.orgPep-Pedia report · Primary source not checked
AI-PREPARED SUMMARY

Pep-Pedia reports: The pooled infertility studies reportedly improved several sperm measures; laboratory semen endpoints do not necessarily predict pregnancy or live birth.

Reported population / model
Meta-analysis

Reported study details
Multiple RCTs · 2g/day · Sperm parameters and hormones

Reported by Pep-Pedia; the linked publication, design, doses and result have not been independently verified here.

Read the Pep-Pedia report ↗

Pep-Pedia reference card; original summary of its reported findings · Checked 2026-10-12

Listed study
10Acetyl-L-Carnitine Cognitive Meta-Analysis (2003)Review · 2003 · doi.orgPep-Pedia report · Primary source not checked
AI-PREPARED SUMMARY

Pep-Pedia reports: The analysis concerns acetyl-L-carnitine in MCI/early Alzheimer's, not interchangeable evidence for every L-carnitine formulation.

Reported population / model
Double-blind RCTs

Reported study details
MCI and mild AD patients · 3 months minimum · Clinical scales

Reported by Pep-Pedia; the linked publication, design, doses and result have not been independently verified here.

Read the Pep-Pedia report ↗

Pep-Pedia reference card; original summary of its reported findings · Checked 2026-10-12

Listed study
11Lipid Profile Umbrella Meta-Analysis (2023)Review · 2023 · doi.orgPep-Pedia report · Primary source not checked
AI-PREPARED SUMMARY

Pep-Pedia reports: The umbrella analysis reports lower total cholesterol, triglycerides and LDL, with higher HDL across heterogeneous populations.

Reported population / model
13 meta-analyses pooled

Reported study details
Multiple populations · Comprehensive lipid outcomes

Reported by Pep-Pedia; the linked publication, design, doses and result have not been independently verified here.

Read the Pep-Pedia report ↗

Pep-Pedia reference card; original summary of its reported findings · Checked 2026-10-12

Listed study
12Intestinal microbiota metabolism of L-carnitine, a nutrient in red meat, promotes atherosclerosisResearch reference · Accessed 2026 · doi.orgLinked reference · Not independently reviewed
REFERENCE NOTE

Listed in Pep-Pedia’s bibliography; the linked publication and its findings have not been independently verified in this pass.

Pep-Pedia bibliography · Checked 2026-10-12

Listed source
13Meta-analysis of double blind randomized controlled clinical trials of acetyl-L-carnitine versus placebo in the treatment of mild cognitive impairment and mild Alzheimer's diseaseReview · Accessed 2026 · doi.orgLinked reference · Not independently reviewed
REFERENCE NOTE

Listed in Pep-Pedia’s bibliography; the linked publication and its findings have not been independently verified in this pass.

Pep-Pedia bibliography · Checked 2026-10-12

Listed source
14L-Carnitine L-tartrate supplementation favorably affects markers of recovery from exercise stressResearch reference · Accessed 2026 · doi.orgLinked reference · Not independently reviewed
REFERENCE NOTE

Listed in Pep-Pedia’s bibliography; the linked publication and its findings have not been independently verified in this pass.

Pep-Pedia bibliography · Checked 2026-10-12

Listed source
15The effect of (L-)carnitine on weight loss in adults: a systematic review and meta-analysis of randomized controlled trialsReview · Accessed 2026 · doi.orgLinked reference · Not independently reviewed
REFERENCE NOTE

Listed in Pep-Pedia’s bibliography; the linked publication and its findings have not been independently verified in this pass.

Pep-Pedia bibliography · Checked 2026-10-12

Listed source
16Kinetics, pharmacokinetics, and regulation of L-carnitine and acetyl-L-carnitine metabolismResearch reference · Accessed 2026 · doi.orgLinked reference · Not independently reviewed
REFERENCE NOTE

Listed in Pep-Pedia’s bibliography; the linked publication and its findings have not been independently verified in this pass.

Pep-Pedia bibliography · Checked 2026-10-12

Listed source
17Acetyl-L-Carnitine Supplementation and the Treatment of Depressive Symptoms: A Systematic Review and Meta-AnalysisReview · Accessed 2026 · doi.orgLinked reference · Not independently reviewed
REFERENCE NOTE

Listed in Pep-Pedia’s bibliography; the linked publication and its findings have not been independently verified in this pass.

Pep-Pedia bibliography · Checked 2026-10-12

Listed source
18The bright and the dark sides of L-carnitine supplementation: a systematic reviewReview · Accessed 2026 · doi.orgLinked reference · Not independently reviewed
REFERENCE NOTE

Listed in Pep-Pedia’s bibliography; the linked publication and its findings have not been independently verified in this pass.

Pep-Pedia bibliography · Checked 2026-10-12

Listed source
19L-Carnitine and Acetyl-L-carnitine Roles and Neuroprotection in Developing BrainResearch reference · Accessed 2026 · doi.orgLinked reference · Not independently reviewed
REFERENCE NOTE

Listed in Pep-Pedia’s bibliography; the linked publication and its findings have not been independently verified in this pass.

Pep-Pedia bibliography · Checked 2026-10-12

Listed source
20Pep-Pedia: L-Carnitine — reported pharmacokineticsReference estimate; not independently verified human PKCommunity · 2026 · pep-pedia.orgCommunity source checked
AI-PREPARED SUMMARY

Lists a half-life of 17 hrs and a peak time of 3.5 hrs. Stated attribution: FDA Carnitor Label. This value is reported by a secondary reference. The stated attribution has not been independently verified as a route- and formulation-matched human PK measurement. Five half-lives is not complete clearance, and the source’s “cleared” value is not used as a measured endpoint.

Secondary reference page checked; the underlying quantitative claim is not independently confirmed. · Checked 2026-10-12

Original source
21CARNITOR injection: route-specific pharmacokinetics and indicationsRegulator · 2023 · dailymed.nlm.nih.govPrimary source checked
AI-PREPARED SUMMARY

The label reports an apparent terminal half-life of 17.4 hours following a slow IV bolus, using plasma concentrations uncorrected for endogenous levocarnitine. Its separate 3.3-hour peak measurement is from oral dosing; the two are not combined into one IV absorption curve.

Original source
22Pep-Pedia: L-Carnitine — route-specific referenceReference page checked; underlying claims require separate verification.Community · Checked 2026 · pep-pedia.orgCommunity source checked
AI-PREPARED SUMMARY

Source page checked across available routes. Protocols, cycles, storage, mechanisms and pairing claims are secondary reports; checking the page does not independently validate those claims. Original concise summaries are used here.

Content coverage audit · Checked 2026-10-12

Original source
Source details