First, a study showed that histidine supplementation can improve lung function, decrease inflammatory cells and cytokines in bronchoalveolar lavage in COPD mice 33
Sandler RH, Finegold SM, Bolte ER, Buchanan CP, Maxwell AP, Vaisanen ML et al
Some of that fuel goes towards maintaining the systems themselves charging the batteries, cycling coolant and oil through the engine, etc
With the addition of the acetyl group, ALCAR can cross the blood-brain barrier, making it useful for supporting brain health
Whats most concerning in the recent Journal of Clinical Investigation study that l-carnitine supplementation, even among vegan/vegetarians, has an effect on gut microbiota and can increase TMAO
They are research chemicals and are not approved for human use by regulatory bodies in many places