Levocarnitine
L-carnitine
Also known as: Carnitor · L-Carnitine · Vitamin B(T) · levocarnitinum
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Trial for treating canine dilated cardiomyopathy (large or giant breed dog) | 2 grams PO q8-12h | PO | q8-12h | — | 🌎 NA |
| Adjunctive therapy of dilated cardiomyopathy in American Cocker spaniels | 1 gram PO q8-12h | PO | q8-12h | — | 🌎 NA |
| Severe myocardial failure in Boxers | 2-3 grams PO q12h | PO | q12h | 2-4 months | 🌎 NA |
| Adjunctive treatment of American cocker spaniels with dilated cardiomyopathy | 1 g PO q12h | PO | q12h | — | 🌎 NA |
| Dilated cardiomyopathy in American Cocker spaniels | 1 g PO q8h | PO | q8h | — | 🌎 NA |
| Dilated cardiomyopathy in Boxer dogs | 2 g PO q8h | PO | q8h | — | 🌎 NA |
| Documented systemic carnitine deficiency | 50-100 mg/kg PO q8h | PO | q8h | — | 🌎 NA |
| Myocardial carnitine deficiency only | 200 mg/kg PO q8h | PO | q8h | — | 🌎 NA |
- Trial for treating canine dilated cardiomyopathy (large or giant breed dog): Approximately 1 teaspoonful of pure powder
- Adjunctive therapy of dilated cardiomyopathy in American Cocker spaniels: Give with taurine. Approximately 1/2 teaspoonful.
- Severe myocardial failure in Boxers: To determine if they respond
- Adjunctive treatment of American cocker spaniels with dilated cardiomyopathy: Give with taurine 500 mg q12h PO
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Adjunctive dietary therapy in cats with severe hepatic lipidosis | 250 mg PO once daily | PO | q24h | — | 🌎 NA |
| Supplementation in cats with liver disease | 250-500 mg/day | PO | q24h | — | 🌎 NA |
- Adjunctive dietary therapy in cats with severe hepatic lipidosis: Use Carnitor; also supplement with taurine (250 mg once to twice daily), Vitamin E (10 Units/kg/day), water soluble vitamins and determine B12 status (treat while awaiting data at 1 mg/cat SC).
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Levocarnitine (L-carnitine) is a naturally occurring amino acid derivative synthesized in vivo from methionine and lysine, essential for normal fat utilization and energy metabolism.
In veterinary medicine, it is primarily utilized as a nutraceutical adjunct for:
- Dilated Cardiomyopathy (DCM) in dogs (especially American Cocker Spaniels and Boxers, where up to 90% may have a carnitine deficiency).
- Feline Hepatic Lipidosis, where it facilitates hepatic lipid metabolism and clearance.
- Protection against doxorubicin-induced cardiomyopathy.
- Adjunctive treatment for valproic acid toxicity.
Clinical Pearl: Only the L-isomer (levocarnitine) is biologically active and beneficial. Racemic mixtures containing D-carnitine must be avoided as they competitively inhibit L-carnitine uptake and can induce a deficiency.
Mechanism of action
Levocarnitine acts as an essential cofactor for the carnitine palmitoyltransferase (CPT) system.
It binds to long-chain free fatty acids in the cytosol, forming acylcarnitine, which is then transported across the inner mitochondrial membrane.
Inside the mitochondria → the fatty acids undergo beta-oxidation → generating ATP (cellular energy). This mechanism is particularly crucial for the myocardium, which relies heavily on fatty acid oxidation for energy, and for the liver during states of lipid mobilization (e.g., feline hepatic lipidosis).
Safety & warnings
Contraindications
- Use of D-carnitine or racemic (D,L) mixtures (competitively inhibits L-carnitine uptake)
Adverse effects
- Gastrointestinal upset (loose stools, diarrhea, nausea, vomiting) - usually mild and dose-dependent
- Increased body odor (reported in human patients)
Precautions
Use only the Levo- (L-) forms of carnitine. Products labeled as 'Vitamin BT' may contain both D and L racemic forms; the D-form competitively inhibits L-uptake and can cause a deficiency. Generally considered safe to use during pregnancy (FDA Category B in humans), though documented safety in pregnant animals has not been definitively established.
Drug interactions
Patients receiving valproic acid may require higher dosages of levocarnitine due to drug-induced carnitine depletion.
Monitoring
- Clinical efficacy (improvement in cardiac or hepatic signs)
- Periodic blood chemistries (recommended in humans, value in veterinary medicine is undetermined)
Pharmacokinetics
Absorption
In humans, absorbed rapidly in the intestine via passive and active mechanisms, but overall GI bioavailability is low (about 15%).
Distribution
Highest levels are found in skeletal muscle. Distributed into milk.
Metabolism
Synthesized in vivo from methionine and lysine.
Elimination
Exogenously administered levocarnitine is eliminated by both renal and fecal routes. Plasma levels may be increased in patients with renal failure.
Overdose
Levocarnitine is a relatively safe drug.
- Minor overdoses: Need only to be monitored.
- Massive overdoses: Consider gut emptying (emesis or gastric lavage). Refer to a veterinary poison control center for more information.
Available products
Formulations
- Oral Tablets
- Oral Capsules
- Oral Solution
- Injection
- Bulk powder
Human-labeled
- Levocarnitine Oral Tablets: 330 mg & 500 mg (Carnitor, generic)
- Levocarnitine Oral Capsules: 250 mg (generic)
- Levocarnitine Oral Solution: 100 mg/mL (Carnitor, generic)
- Levocarnitine Injection: 200 mg/mL in single-dose vials & amps (Carnitor, generic)
Regulatory status
No regulatory data for: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Capsules, tablets, and powder should be stored in well-closed containers at room temperature. Oral solution should be kept in tight containers at room temperature. Injection should be stored at room temperature in the original carton; discard any unused portion after opening, as the injection contains no preservative.
Client information
Administration: Give this supplement with meals whenever possible to reduce the likelihood of gastrointestinal side effects like loose stools or nausea.
Expectations: For heart conditions (like dilated cardiomyopathy), this supplement is usually part of a broader treatment plan. The majority of dogs responding to carnitine therapy will still require their other prescription medications to control clinical signs.
Product Selection: Ensure you are purchasing L-carnitine (levocarnitine). Avoid products containing D-carnitine or racemic mixtures, as they can interfere with the body's ability to use the supplement.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.