A Guide to L-Carnitine! Always a popular supplement, it is used for a wide range of reasons, from fat loss to ATP energy. Add in the variations, and the list of benefits gets even longer. In this Guide, we’ll look at what it is, the different forms, and what supplements contain it. Let’s get started!

What is L-Carnitine?

This impressive nutrient comes from the combination of the amino acids methionine and lysine. It is naturally produced in the liver and kidneys. (1)

What Does It Do?

It is responsible for the transport of stored fat to the mitochondria, where it is then burned or used for energy. Many lifters and average people think of caffeine when they think of energy. However, that is a central nervous system stimulant. The energy I mean in this case is ATP, which is what the muscles use when you work out. Specifically, it is used for muscle contraction, ion transport in the body, and chemical synthesis, to name a few. (2)

What Else Is It Used For? 

In supplement form it is typically used to help burn fat and reduce muscular fatigue. As we will soon see, the other forms of this impressive nutrient provide additional benefits that are unique to that specific form.

How Many Types Are There?

All types of l-carnitine support the production of ATP energy. However, as noted, the other types have benefits that are exclusive to that type. Some of the other types include:

L-Carnitine L-Tartrate (or, LCLT)

This is a combination of standard l-carnitine and l-tartrate, which is a salt that enhances absorption. LCLT helps testosterone work more effectively, which promotes muscle growth. It also aids recovery by helping to ease muscle soreness. (3, 4)

Acetyl-L-Carnitine (or, ALCAR)

This type has a range of impressive cognitive benefits. These include mood enhancement and improved learning ability. (5)

N-Acetyl L-Carnitine Hydrochloride

Similar to ALCAR, this type supports cognitive function. The primary way it does this is by promoting the production of the neurotransmitter acetylcholine (commonly known as the “learning neurotransmitter). (6)

Glycine Propionyl L-Carnitine (or, GPLC)

This type is a blend of propionyl-l-carnitine (PLC) and glycine, an amino acid. This type promotes nitric oxide production for better pumps and enhanced nutrient delivery. (7)

GBB (or Gamma-Butyrobetaine Ethyl Ester HCl)

GBB is an ingredient commonly known as “Super Carnitine”. It is an interesting molecule because it helps the body make its own carnitine. GBB also has thermogenic properties, making it a great option for fat loss. Additionally, like GPLC, it supports the production of nitric oxide. (8)

Product Suggestions

There’s some excellent supplement choices available. They include:

5% Nutrition Liquid L-Carnitine 3150

This is an innovative formula that is dosed at 3150 mg per serving. It combines 4 different forms of carnitine and includes GBB. 

Pro Supps L-Carnitine 3000

This product provides 3,000 mg per serving and is available in 3 flavors. 

 

You can see all our l-carnitine products here. 

Summary

It should be clear that this is an impressive nutrient that promotes the use of fat for ATP energy. As we have seen, different forms provide a range of additional benefits. Of course, illpumpyouup.com has a wide selection of l-carnitine supplements. Stop by and stock up today!

 

References:

1. https://ods.od.nih.gov/factsheets/Carnitine-HealthProfessional/
2. Dunn J, Grider MH. Physiology, Adenosine Triphosphate. [Updated 2023 Feb 13]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK553175/
3. Kraemer, W. J., Spiering, B. A., Volek, J. S., Ratamess, N. A., Sharman, M. J., Rubin, M. R., . . . Maresh, C. M. (2006, July). Androgenic responses to resistance exercise: Effects of feeding and L-carnitine. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/16826026
4. Volek, J. S., Kraemer, W. J., Rubin, M. R., Gómez, A. L., Ratamess, N. A., & Gaynor, P. (2002). L-Carnitine L-tartrate supplementation favorably affects markers of recovery from exercise stress. American journal of physiology. Endocrinology and metabolism, 282(2), E474–E482. https://doi.org/10.1152/ajpendo.00277.2001
5. Traina, G. (2016, June 01). The neurobiology of acetyl-L-carnitine. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/27100509
6. Rebouche CJ, Engel AG. Carnitine metabolism and deficiency syndromes. Mayo Clinic Proceedings. 1983 Aug;58(8):533-540.
7. Bloomer, R. J., Tschume, L. C., & Smith, W. A. (2009, May). Glycine propionyl-L-carnitine modulates lipid peroxidation and nitric oxide in human subjects. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/20209464
8. https://academic.oup.com/jn/article-abstract/119/12/1907/4738183