Boost your energy. Support fat metabolism. , L Carnitine options now available to match your fitness goals:, AN L Carnitine 3000mg $214 , RSP L Carnitine 3000mg $231 , NOW L Carnitine 500mg Acetyl L Carnitine ALC (ALCAR) Carnitine: Requirements, food sources, benefits, and risks Happy Supplement Sunday! Each of the supplements displayed in today's graphic have some scientific evidence supporting a benefit on liver enzyme (and potentially other markers) levels in people living with a fatty L carnitine is a naturally occurring amino acid structure that is made in the human brain, liver, and kidneys. L carnitine plays a critical role in energy production, as it converts fat into energy.