Doctor's Best Acetyl-L-Carnitine is pure Acetyl-L-Carnitine. This is different from fumarate, tartrate and fumarate.

Doctor's Best ACETYL-L-CARNITINE 60vcaps
Doctor's Best ACETYL-L-CARNITINE 60vcaps
Boost your performance - behind the desk and on the field. Naturally produced by the body, Acetyl L-Carnitine is an amino acid that helps to supply the brain with energy.* By increasing mitochondrial efficiency, Acetyl L-Carnitine acts as both a brain function and overall energy enhancer. Taken daily, this supplement can support the improvement of memory, learning and focusing...so you can stay quick, sharp and ready for whatever comes next.*
We only use the best ingredients in all our products, and our Acetyl-L-Carnitine is no exception. This supplement contains Biosint Carnitine™ L-carnitine fumarate, which is derived from high grade L-carnitine manufactured by a patented, FDA-approved process. This guarantees the highest levels of efficacy, safety and quality. Even more impressive, this product is backed by 40 years of research by the Sigma-Tau Group, who studied the role played by carnitine in cellular metabolism.