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L-Carnitine Side Effects

Generic Name: levocarnitine

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

For the Consumer

Applies to levocarnitine: capsule, powder, solution, tablet, wafer

In addition to its needed effects, some unwanted effects may be caused by levocarnitine (the active ingredient contained in L-Carnitine). In the event that any of these side effects do occur, they may require medical attention.

Severity: Moderate

If any of the following side effects occur while taking levocarnitine, check with your doctor or nurse as soon as possible:

More common:
  • High blood pressure
Less common:
  • Fast heartbeat
  • fever
  • Seizures

Minor Side Effects

Some of the side effects that can occur with levocarnitine may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

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]


There are reports from clinical trials of significant hypertriglyceridemia associated with high doses of levocarnitine (the active ingredient contained in L-Carnitine) (3 g/day) given to uremic dialysis patients.[Ref]

Very common (10% or more): Hypercalcemia (15%), hypervolemia (12%)
Common (1% to 10%): Anorexia, hyperkalemia[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]


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

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


1. "Product Information. LevOCARNitine (levOCARNitine (levocarnitine))." Hi-Tech Pharmacal Company Inc, Amityville, NY.

2. "Product Information. Carnitor (levocarnitine)" Sigma-Tau Pharmaceuticals Inc, Gaithersburg, MD.

3. "Product Information. Carnitor (levocarnitine)." Sigma-Tau Pharmaceuticals, Gaitherburg, MD.

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

5. Weschler A, Aviram M, Levin M, Better OS, Brook JG "High dose of L-carnitine increases platelet aggregation and plasma triglyceride levels in uremic patients on hemodialysis." Nephron 38 (1984): 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 "L-carnitine and platelet aggregation in uremic patients subjected to hemodialysis." Nephron 55 (1990): 28-32

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

Not all side effects for L-Carnitine may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.