Where the genuine literature exists it is overwhelmingly cell culture and rodent, and the rodent work in particular is routinely over-extrapolated in secondary writing
P.AsconaM.et al
Furthermore, L-carnitine upregulates genes involved in fatty acid transport and mitochondrial -oxidation ( Octn2, Cpt1a, Cpt2, Acadm ) while increasing metabolites associated with TCA cycle, urea cycle, and antioxidant pathways (malate, citrulline) (45)
This widespread use underscores the need to understand how these compounds might be safely repurposed as evidencebased adjuncts to conventional oncology therapies, particularly for patients seeking to improve quality of life and treatment outcomes under medical supervision

Gastrointestinal adverse events 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] Metabolic 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