Road2HardCoreIron

The main difference between L-carnitine and acetyl L-carnitine is that acetyl L-carnitine has an acetyl group that allows it to cross the blood-brain barrier more effectively. This makes acetyl L-carnitine better for brain health and cognitive function, while L-carnitine is better for physical performance:
 
Acetyl L-carnitine
This processed form of L-carnitine can support brain health, memory, focus, and cognitive function. It's also been studied for its potential to protect against neurodegenerative processes and brain aging. Doses vary from 500–3,000 mg per day.
 
L-carnitine
This amino acid supplement helps mobilize fat from fat storage deposits and convert it into energy. It's popular with athletes and may help with burning fat, building muscle, increasing energy, and boosting endurance. Doses for L-carnitine L-tartrate vary from 1,000–4,000 mg per day.