MetabolicSmall molecule

L-Carnitine

Levocarnitine, an endogenous carnitine compound

Studied forCarnitine deficiency212

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

What does it do?

Levocarnitine supports fatty-acid transport; prescription products treat specified deficiency states. Oral supplements and carnitine derivatives have different evidence from IV treatment.

Approved & studied uses

Carnitine deficiency

Approved indication21

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

Deficiency and dialysis research

2

Defined clinical settings differ from weight-loss injections.

Community uses Reported, unvalidated

Deficiency and dialysis

22

Approved product/route-specific replacement.

Weight and energy

22

Modest oral trial effects; not proof of injectable fat loss.

Heart and circulation

22

Cardiac/PAD studies vary by formulation.

Cognition, exercise and fertility

22

ALCAR, LCLT and sperm-parameter research; not interchangeable outcomes.

Reasons people report using it; these do not establish benefit.22

Evidence limits

View research →

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 →

Key safety information

All risks →

Seizure reports

Seizures have been reported with oral and IV levocarnitine, including increased frequency or severity in people with prior seizures.3

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

Molecular information

Amino-acid sequence

Not applicable: this compound is not a single peptide.

LengthNonpeptide
Molecular weight · Da161.20 Da
Formula, sequence notation & identity
Molecular formulaC7H15NO34

Levocarnitine, R-enantiomer inner salt

Hydrochloride and tartrate salts have different composition and mass.

Pharmacokinetics

How long does it stay in the body?

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.

Evidence and model details

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.

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.
Protocols

Doses & schedules

Compare purpose, amount, route, frequency, and duration.

Source corrections

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

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 comparisonHuman study24 weeks2
IVIntravenous20 mg/kgAfter dialysisRenal anemia route comparisonHuman 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

Full storage notes from Pep-Pedia22
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.

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.

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.
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.

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