After some research, I determined that ALCAR would probably be better than the free form L-Carnitine. I have started using it for the last week and it seems to last longer and is more "focused" in my head and not my body. I am only at 1,000mg currently; will adjust as needed.
Carnitine, specifically Acetyl-L-Carnitine (ALCAR), is being investigated for chronic fatigue syndrome as a biomarker of fatigue is alterations in the levels and distribution of ALCAR in the brain at rest; specifically the pre-frontal cortex. This tends to be accompanied by a reduced uptake of ALCAR into the brain, which may precede the reduced neural levels of ALCAR.
10.1. Fatigue in Healthy Humans and Animals
Supplementing ALCAR into the feed of animals increases ambulatory activity (defined as overall distance traveled) in both young and old rats, although the increase is typically much greater in older rats.
In otherwise healthy humans, Acetyl-L-Carnitine at 2g (paired with another 2g of Propionyl-L-Carnitine) in older men was able to decrease fatigue while alleviating symptoms of 'andropause' (erectile dysfuntion). Older individuals still (71-78) experience reductions in fatigue, as well as improvements in sleep disorders related to fatigue and reductions in post-exercise fatigue.
10.2. Fatigue in other Disease States
It has been shown to decrease fatigue in a human population of hepatic encepalopathy, secondary to reducing ammonia levels which tend to induce fatigue, reduce quality of life, and hinder cognition. As these benefits are seen by therapeutically reducing ammonia, they are unlikely to translate into other disease states. The connection of anti-fatigue is coincidental.
L-Carnitine supplementation has been shown to improve fatigue in persons with Celiac disease related fatigue, but requires adherence to a gluten-free diet prior to intervention to restore intestinal uptake of carnitine. The mechanism of this improvement in fatigue is not known.
As an adjunct therapy for cancer, L-Carnitine may decrease fatigue indirectly through increased lean mass and reducing cancer cachexia. Carnitine deficiency is prevalent among some forms of Cancer and reversing this deficiency can theoretically reverse fatigue. That being said, not all studies come back positive. Doses tend to be around 2-3g daily of L-Carnitine or Acetyl-L-Carnitine.