L-Carnitine vs Acetyl L-Carnitine - What's the Difference
The Short Answer:
They are two different forms of the same Amino Acid, but they work differently. The L-Carnitine helps the body convert fat into energy, so it’s typically used by people who are exercising and/or trying to lose weight. The Acetyl L-Carnitine is essentially a processed form of L-Carnitine that can pass the blood-brain barrier to help energize the brain.
The Robust Answer:
Acetyl L-Carnitine is the preferred form of Carnitine for brain and nerve support because the acetyl group enables the molecule to cross the blood-brain barrier more easily and may also provide substrate (acetyl groups) for synthesis of acetylcholine—a primary neurotransmitter in the brain. The Acetyl L-Carnitine helps for converting fat into energy, but much less as a “primary benefit” than the regular L-Carnitine does. It’s like saying that you can eat an orange for your fiber intake (as that is one benefit of eating oranges), but most people take it for the Vitamin C content, as that’s a more prevalent benefit compared to other.
In general, though, the various forms of carnitine which are available (Acetyl l-Carnitine, l-Carnitine Fumarate, GPLC, l-Carnitine Tartrate, ArginoCarn) will provide support for nervous system, cardiovascular system and muscles; even though a specific form may be preferred for a particular function, you’ll still get general support for all functions regardless of the form used. Regular L-Carnitine is often used to support weight loss (along with diet and exercise of course) and enhancement for body-building since it helps to mobilize fat from storage deposits and move it to the mitochondria to burn as energy.
Can You Take L-Carnitine and Acetyl L-Carnitine at the same time?
I understand is supposed to help your body burn fat for energy, and the other one can help with memory.
Yes, you can certainly take Acetyl L-Carnitine and L-Carnitine during the same day, but they should be taken at different times, since the L-Carnitine should be taken on an empty stomach. You can take these two forms of the amino acid L-carnitine together without risk. Various forms will do double duty for assisting in natural fat burning, cardiovascular support and brain support. However, you are right that acetyl L-carnitine is the preferred form for memory support because the acetyl- group passes the blood-brain barrier more easily.
Even though it's OK to take both forms, it may not be necessary. Why? Because Acetyl L-Carnitine actually does everything that regular L-Carnitine does, plus it also can cross the blood/brain barrier and support cognitive functioning while regular L-Carnitine does not.
It is recommended to take the Acetyl L-Carnitine in the morning when you want your brain to be active.
What is N-Acetyl Carnitine (NAC)?
N-Acetyl Carnitine is simply another name for what is usually marketed as Acetyl L-Carnitine for brain and nerve support. Bear in mind that the abbreviation NAC is also used for N-Acetyl Cysteine, which is a precursor for glutathione synthesis in the body. Sometimes the use of abbreviations in the dietary supplement world can be a little confusing—like ALA used for Alpha Linolenic Acid (an Omega-3 Fatty Acid) and Alpha Lipoic Acid (an antioxidant). You have to be really careful about looking at the context to see what the abbreviation is being used for just to be certain.