L-Carnitine
Pronunciation: Not researched.
- Generic name
- levocarnitine
- Drug class
- Amino acid derivative; carnitine supplement
- Form
- Not specified in the reviewed research notes; dosage form is unresolved.
- Route
- Oral
- Legal status
- Prescription-only for specific deficiency indications; over-the-counter dietary supplement for other uses
Availability and supply rules vary by country
Trade names by country: United States · Canada
Australia: · Full directory
What levocarnitine is and how it works
L-carnitine is an amino-acid derivative that transports fatty acids into cell mitochondria for energy production. It is available as an FDA‑approved prescription product (for specific deficiency indications) and as an over‑the‑counter dietary supplement. (1)
Uses and appropriate dosing depend on the condition. Prescription levocarnitine is used under medical supervision for carnitine deficiency. Over‑the‑counter supplements are studied for various other purposes, but evidence for many claimed benefits is limited. Consult a healthcare provider before use, especially if you have a medical condition or take other medications.
Mechanism of action: how levocarnitine works
L-carnitine facilitates the transport of fatty acids into cell mitochondria, where they are used to produce energy. Further pharmacologic detail (e.g., chemical classification, beta-oxidation mechanics) is not established in the reviewed source. (1)
What levocarnitine is used for
Primary and secondary carnitine deficiency
FDA‑approved prescription levocarnitine is used to treat carnitine deficiency resulting from inborn errors of metabolism. (1)
Carnitine deficiency in dialysis patients
Prescription levocarnitine is approved for treatment of carnitine deficiency associated with dialysis in patients with end‑stage renal disease. (1)
Type 2 diabetes (limited to moderate evidence)
L‑carnitine 2 g once daily for 1 year, combined with other medications, was associated with improved weight and glucose parameters in studied research. (1)
Male infertility (limited to moderate evidence)
Doses of L‑carnitine 2–3 g/day, or acetyl‑L‑carnitine 0.5–3 g/day for up to 26 weeks, have been studied for possible benefit to sperm quality. (1)
Intermittent claudication (limited to moderate evidence)
Propionyl‑L‑carnitine 2 g once daily showed benefit in studied research. (1)
Before taking levocarnitine
Do not take / not appropriate for
- The reviewed source identifies no contraindications for L‑carnitine, as reported in that source. (as reported in reviewed source) (1)
- In people with cardiovascular disease, taking L-carnitine at more than 3 grams per day has been associated with a reported increased risk of atherogenesis; discuss any dose with a healthcare provider before use. (supplement use) (1)
Tell your clinician about
- Any history of cardiovascular disease.
- Whether you are on dialysis (relevant to a labeled use of prescription levocarnitine).
- All medications you take, particularly anticonvulsants (carbamazepine, phenobarbital, phenytoin, valproic acid) and pivalate‑conjugated antibiotics, as these may affect carnitine levels.
- If you are pregnant, planning pregnancy, or breastfeeding.
- Your intended use and reason for taking L‑carnitine.
How to take levocarnitine
- L‑carnitine is available as a prescription product and as a dietary supplement. Follow the specific dosing instructions from your healthcare provider or the product label.
- Studied oral doses range from 300 mg to 3 grams per day depending on the condition, but no universal recommended dose exists. Doses should be individualized.
- Discuss the appropriate dose with a healthcare provider, particularly if you have cardiovascular disease, since doses above 3 grams per day have been associated with increased cardiovascular risk in this population.
- If gastrointestinal side effects such as nausea or diarrhea occur, tell your healthcare provider; whether taking L-carnitine with food reduces these effects is not established in the reviewed source.
- Any change to your dose, or to any prescribed medication, should be made only in consultation with your prescriber or healthcare provider.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician.
Missed dose
No specific missed‑dose protocol is available from the reviewed sources. As a general practice, do not take an extra dose to make up for a missed one; consult your healthcare provider for guidance.
Overdose
If overdose is suspected, contact a poison control center or emergency services promptly. In people with cardiovascular disease, doses exceeding 3 grams per day have been associated with increased cardiovascular risk; whether higher doses generally increase gastrointestinal side effects beyond this is not established. (1)
Side effects
Side effects are more common at doses around 3 grams per day and may include nausea, vomiting, abdominal cramps, diarrhea, and a "fishy" body odor. Less common effects include rashes and muscle weakness.
Nausea, vomiting, abdominal cramps, diarrhea
What to notice: Gastrointestinal upset; timing relative to a dose is not established in the reviewed source.
What to do: Whether taking with food reduces these effects is not established in the reviewed source. If symptoms are severe or persistent, consult your healthcare provider. (1)
Fishy body odor
What to notice: A noticeable odor resembling fish, especially at doses around 3 g/day.
What to do: Discuss with your healthcare provider; let them advise on whether any dose change is appropriate. (1)
Rashes and muscle weakness (less common)
What to notice: Skin rash or unexplained muscle weakness.
What to do: Report to your healthcare provider for evaluation. (1)
Severe or persistent gastrointestinal symptoms
What to notice: Gastrointestinal symptoms (nausea, vomiting, abdominal cramps, or diarrhea) that are severe or do not resolve.
What to do: Seek medical attention. (1)
Serious warnings
Cardiovascular risk with high doses — warning
Symptoms: In patients with cardiovascular disease, doses exceeding 3 grams per day may increase the risk of atherogenesis and cardiovascular disease.
Action: Consult a healthcare provider before use if you have heart disease; let them advise on an appropriate dose, since doses above 3 grams per day have been associated with increased risk in this population. (1)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Anticonvulsants (carbamazepine, phenobarbital, phenytoin, valproic acid) | May decrease blood carnitine levels, particularly in children. | Inform your prescribing clinician if you are on these medications; in children, these medicines may decrease blood carnitine levels. (1) |
| Pivalate‑conjugated antibiotics (e.g., pivampicillin) | May reduce carnitine concentrations. | Discuss with your healthcare provider before combining treatments. (1) |
Pregnancy, breastfeeding, kidney/liver function, age
Pregnancy
Historically categorized as Pregnancy Category B (animal studies show no harm, but human data are limited). The reviewed monograph advises avoiding use during pregnancy due to a lack of adequate human studies; a clinician should confirm whether use is appropriate for your individual situation before starting or continuing. (1)
Breastfeeding
Clinical safety data for nursing infants are absent. Breastfeeding mothers should discuss with their healthcare provider whether to continue or stop levocarnitine use; do not decide this alone. (1)
Children
No specific pediatric dosing guidelines were established from the reviewed sources, except that children taking certain anticonvulsants may have decreased carnitine levels. Whether broader pediatric use guidance applies beyond this anticonvulsant-interaction context is not established in the reviewed source; any pediatric use should be discussed with the child’s healthcare provider. (1)
Monitoring
Before starting
- Confirm the diagnosis and need for L‑carnitine (prescription or supplement) with a healthcare provider.
- Review all concurrent medications, particularly anticonvulsants and pivalate antibiotics; the reviewed source establishes that these medicines may affect carnitine levels, not that carnitine-level monitoring is specifically recommended.
- Whether baseline cardiovascular risk or kidney function assessment is needed is not established in the reviewed source; discuss with a healthcare provider.
During treatment
- Monitor for gastrointestinal side effects, body odor, rashes, and muscle weakness.
- Whether clinical response and carnitine levels are formally monitored for prescription deficiency treatment is not established in the reviewed source; follow the prescriber's monitoring plan.
- Discuss any dose above 3 grams per day with a healthcare provider, due to the reported cardiovascular risk.
- Discuss continued need and effectiveness with a healthcare provider; specific reassessment protocols are not established in the reviewed source.
Storage
Storage instructions were not reviewed in this research. Follow the product‑specific storage information on the label.
Professional information
Clinician‑facing context only. All substantive content is drawn from a single secondary source (Drugs.com monograph). The NIH Office of Dietary Supplements fact sheets (health-professional and consumer versions) returned HTTP 403 errors and could not be directly reviewed in this research pass — a material sourcing limitation. No current FDA prescription labeling and no non-US regulatory source (UK/EU, Canada, Australia) was reviewed. Refer to current FDA labeling for prescription levocarnitine and clinical guidelines before any publication decision.
All regions
Indication: Any use
Dose summary: Dosing is condition‑specific and not standardized. For prescription deficiency states, refer to FDA‑approved labeling. Studied oral doses range from 300 mg to 3 g/day, but evidence levels vary. No universal dose can be provided.
Renal context: Specific dosing adjustments for renal impairment (beyond the dialysis‑related deficiency indication) have not been established from the reviewed sources. (1)
Hepatic guidance
No hepatic impairment dosing guidance was found in the reviewed sources.
Overdose note
No specific overdose protocol is established in the reviewed source; management approach remains unresolved. In cardiovascular patients, doses exceeding 3 grams per day have been associated with increased cardiovascular risk. (1)
Frequently asked questions
Can L‑carnitine help with weight loss or exercise performance?
Evidence is currently insufficient to support these uses. Do not rely on L‑carnitine supplements for weight loss or performance enhancement without medical advice. (1)
Is L‑carnitine safe for people with heart disease?
The reviewed source does not report an interaction with heart medications specifically, but doses over 3 grams per day may increase cardiovascular risk in patients with existing cardiovascular disease. Consult your healthcare provider before use. (1)
Can I take L‑carnitine if I am pregnant or breastfeeding?
Safety during pregnancy and breastfeeding has not been established. The reviewed source advises avoiding use during pregnancy, but a clinician should confirm whether use is appropriate for your individual situation; for breastfeeding, discuss with your healthcare provider whether to continue or stop use. (1)
What is the mechanism of action of levocarnitine?
L-carnitine facilitates the transport of fatty acids into cell mitochondria, where they are used to produce energy. Further pharmacologic detail (e.g., chemical classification, beta-oxidation mechanics) is not established in the reviewed source. (1)
What is the generic name of L-Carnitine?
The generic name is levocarnitine. (1)
What class of drug is levocarnitine?
L-Carnitine is classed as: Amino acid derivative; carnitine supplement. (1)
References
- L-Carnitine MonographDrugs.com · United States · accessed 2026-08-05 · source 1
- LEVOCARNITINE INJECTION, SOLUTION [BAXTER HEALTHCARE CORPORATION] — US prescribing information (DailyMed SPL)U.S. National Library of Medicine (DailyMed) · US · accessed 2026-08-14 · source 2
- Levocarnitine — FDA approval record (Drugs@FDA ANDA212533)U.S. Food and Drug Administration · US · accessed 2026-08-14 · source 3
- levocarnitine — RxNorm normalized drug concept (RXCUI 1426681)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 4
Brand names by country
Single-ingredient levocarnitine names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
United States
- Carnitor1 g0mL, 330 mg, 1 g/5mL · leadiant biosciences, inc.
Canada
- CARNITOR - LIQ IV
- CARNITOR
- CARNITOR - LIQ ORL