L-Carnitine Side Effects: Common, Severe, Long Term (2024)

Generic name: levocarnitine

Medically reviewed by Drugs.com. Last updated on Nov 30, 2023.

Note: This document contains side effect information about levocarnitine. Some dosage forms listed on this page may not apply to the brand name L-Carnitine.

Applies to levocarnitine: capsule, capsule liquid filled, solution, tablet.

Serious side effects of L-Carnitine

Along with its needed effects, levocarnitine (the active ingredient contained in L-Carnitine) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur while taking levocarnitine:

More common

  • High blood pressure

Less common

  • Fast heartbeat
  • fever


  • Seizures

Other side effects of L-Carnitine

Some side effects of levocarnitine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  • Abdominal or stomach cramps
  • diarrhea
  • headache
  • nausea or vomiting

Less common

  • Abdominal discomfort
  • body odor
  • depression
  • dizziness
  • impaired vision
  • loss of appetite or weight
  • swelling in hands, lower legs, and feet
  • tingling sensation
  • weakness

For Healthcare Professionals

Applies to levocarnitine: injectable solution, oral capsule, oral solution, oral tablet.


Very common (10% or more): Diarrhea (35%), abdominal pain (21%), vomiting (21%), nausea (12%)

Common (1% to 10%): Constipation, dyspepsia, gastrointestinal disorder, melena

Very rare (less than 0.01%): Abdominal cramps[Ref]

Nervous system

Very common (10% or more): Headache (37%), dizziness (18%), paresthesia (12%)

Common (1% to 10%): Hypertonia, vertigo, taste perversion

Frequency not reported: Seizures (with or without pre-existing seizure activity), increase in seizure frequency and/or severity[Ref]


Very common (10% or more): Hypercalcemia (15%), hypervolemia (12%)

Common (1% to 10%): Anorexia, hyperkalemia[Ref]

There are reports from clinical trials of significant hypertriglyceridemia associated with high doses of levocarnitine (3 g/day) given to uremic dialysis patients.[Ref]


Very common (10% or more): Pain (35%), flu syndrome (29%), chest pain (15%), accidental injury (12%), asthenia (12%), fever (12%)

Common (1% to 10%): Peripheral edema, weight decrease, weight increase

Very rare (less than 0.01%): Body odor, International Normalized Ratio (INR) increased[Ref]


Very common (10% or more): Injection site reaction (38%)[Ref]


Musculoskeletal side effects, in chronic hemodialysis patients, for levocarnitine (the active ingredient contained in L-Carnitine) in relation to placebo therapy have included asthenia (8% to 12% vs 8%) and leg cramps (4% to 8% vs 13%). Mild myasthenia has occurred in uremic patients receiving D,L-carnitine (but not levocarnitine).[Ref]


Very common (10% or more): Anemia (12%)[Ref]

There have been reports from clinical trials of significant increases in platelet aggregation associated with high doses of levocarnitine (3 g/day) given to hemodialysis patients.[Ref]


Common (1% to 10%): Kidney failure (chronic hemodialysis patients)[Ref]


Common (1% to 10%): Parathyroid disorder[Ref]


Very common (10% or more): Pharyngitis (27%), cough increase (18%), dyspnea (11%), rhinitis (11%)

Common (1% to 10%): Bronchitis, sinusitis[Ref]


Common (1% to 10%): Pruritus, rash[Ref]


Common (1% to 10%): Amblyopia, eye disorder[Ref]


Common (1% to 10%): Urinary tract infection[Ref]


Very common (10% or more): Hypertension (21%), hypotension (19%)

Common (1% to 10%): Atrial fibrillation, arrhythmia, cardiovascular disorder, electrocardiogram abnormal, palpitations, tachycardia, vascular disorder[Ref]


Common (1% to 10%): Allergic reaction[Ref]


Common (1% to 10%): Depression, anxiety, drug dependence, insomnia[Ref]


Very common (10% or more): Infection (24%)[Ref]

More about L-Carnitine (levocarnitine)

  • Check interactions
  • Compare alternatives
  • Reviews (4)
  • Dosage information
  • During pregnancy
  • Drug class: nutraceutical products
  • Breastfeeding
  • En español

Patient resources

  • Carnitine advanced reading

Other brands

Carnitor, Carnitor SF

Professional resources

  • L-carnitine product monographs
  • Levocarnitine (AHFS Monograph)
  • Levocarnitine Tablet (FDA)

Other brands

Carnitor, Carnitor SF

Related treatment guides

  • Peripheral Neuropathy
  • Carnitine Deficiency


1. (2001) "Product Information. Carnitor (levocarnitine)." Sigma-Tau Pharmaceuticals

2. (2022) "Product Information. LevOCARNitine (levOCARNitine)." Hi-Tech Pharmacal Company Inc

3. Golper TA, Wolfson M, Ahmad S, Hirschberg R, Kurtin P, Katz LA, Nicora R, Ashbrook D, Kopple JD (1990) "Multicenter trial of L-carnitine in maintenance hemodialysis patients. I. Carnitine concentrations and lipid effects." Kidney Int, 38, p.904-11

4. Lacour B, Di Giulio S, Chanard J, Ciancioni C, Haguet M, Lebkiri B, Basile C, Drueke T, Assan R, Funck-Brentano JL (1980) "Carnitine improves lipid anomalies in haemodialysis patients." Lancet, 2, p.763-4

5. Weschler A, Aviram M, Levin M, Better OS, Brook JG (1984) "High dose of L-carnitine increases platelet aggregation and plasma triglyceride levels in uremic patients on hemodialysis." Nephron, 38, p.120-4

6. Bellinghieri G, Savica V, Barbera CM, Ricciardi B, Egitto M, Torre F, Valentini G, D'Iddio S, Bagiella E, Mallamace A, et al. (1990) "L-carnitine and platelet aggregation in uremic patients subjected to hemodialysis." Nephron, 55, p.28-32

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circ*mstances.

Some side effects may not be reported. You may report them to the FDA.

Medical Disclaimer

L-Carnitine Side Effects: Common, Severe, Long Term (2024)
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