What the label lists and what reports show
Levocarnitine side effects
Levocarnitine's FDA label lists its adverse reactions in its own words. FAERS holds 3,587 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is seizure (388 reports).
- Generic listed
Check it at the source: the levocarnitine FDA label on DailyMed (effective November 4, 2024, Leadiant Biosciences, Inc.); the FDA FAERS public dashboard.
What does the label list?
From the label: adverse reactionsThe following adverse reactions associated with the use of oral formulations of levocarnitine were identified in clinical trials or postmarketing reports. Because these reactions were reported voluntarily from a population of uncertain size, it is not always possible to estimate their frequency, reliability, or to establish a causal relationship to drug exposure. Gastrointestinal Reactions: Various mild gastrointestinal complaints have been reported during the long-term administration of oral L- or D,L-carnitine; these include transient nausea and vomiting, abdominal cramps, and diarrhea. Gastrointestinal adverse reactions with CARNITOR ® (levocarnitine) Oral Solution or CARNITOR ® SF (levocarnitine) Sugar-Free Oral Solution dissolved in liquids might be avoided by a slow consumption of the solution or by a greater dilution. …
Adverse Events with a Frequency ≥5% Regardless of Causality by Body System
This table is printed in the Carnitor label published by Leadiant Biosciences, Inc. of November 20, 2023; the label quoted above does not print one.
| Reaction | Placebo (n=63) | Levocarnitine 10 mg (n=34) | Levocarnitine 20 mg (n=62) | Levocarnitine 40 mg (n=34) | Levocarnitine 10, 20 & 40 mg (n=130) |
|---|---|---|---|---|---|
| Abdominal pain | 17 | 21 | 5 | 6 | 9 |
| Accidental injury | 10 | 12 | 8 | 12 | 10 |
| Asthenia | 8 | 9 | 8 | 12 | 9 |
| Back pain | 10 | 9 | 8 | 6 | 8 |
| Chest pain | 14 | 6 | 15 | 12 | 12 |
| Fever | 5 | 6 | 5 | 12 | 7 |
| Flu syndrome | 40 | 15 | 27 | 29 | 25 |
| Headache | 16 | 12 | 37 | 3 | 22 |
| Infection | 17 | 15 | 10 | 24 | 15 |
| Injection site reaction | 59 | 38 | 27 | 38 | 33 |
| Pain | 49 | 21 | 32 | 35 | 30 |
| Cardiovascular disorder | 6 | 3 | 5 | 6 | 5 |
| Hemorrhage | 6 | 9 | 2 | 3 | 4 |
| Hypertension | 14 | 18 | 21 | 21 | 20 |
| Hypotension | 19 | 15 | 19 | 3 | 14 |
| Tachycardia | 5 | 6 | 5 | 9 | 6 |
| Anorexia | 3 | 3 | 5 | 6 | 5 |
| Constipation | 6 | 3 | 3 | 3 | 3 |
| Diarrhea | 19 | 9 | 10 | 35 | 16 |
| Nausea | 10 | 9 | 5 | 12 | 8 |
| Vomiting | 16 | 9 | 16 | 21 | 15 |
| Parathyroid disorder | 2 | 6 | 2 | 6 | 4 |
| Anemia | 3 | 3 | 5 | 12 | 6 |
| Hypercalcemia | 3 | 15 | 8 | 6 | 9 |
| Hyperkalemia | 6 | 6 | 6 | 6 | 6 |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
Source: FDA drug label, Leadiant Biosciences, Inc., effective November 4, 2024 (SPL set dd904490-83f3-4cd3-bb6f-68e28509b4b6), via openFDA; the full label on DailyMed
What do FAERS reports show?
3,587 reports list levocarnitine among the medicines taken, each a report of something that happened, not proof the medicine caused it; 392 are coded as a death and 1,693 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 18 reactions below, 7 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Levocarnitine: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions