L Carnitine: Everything You Need to Know When nutraceuticals show benefit as antidepressant add ons, it's usually not because they're acting like drugs. Most antidepressants target neurotransmitters. Response is often limited by other factors (inflammation, nutrient status, energy metabolism Acetyl L Carnitine Natural Medicine Formulas A review of current evidence for acetyl l carnitine in the treatment of depression ScienceDirect