Lipotropes are compounds that may aid in the breakdown of body fat by acting on lipid metabolism and synthesis pathways. When used in combination with lifestyle modifications such as exercise and diet, lipotropic compounds may promote fat and weight loss.
Lipotropic compounds including vitamins, nutrients, and other natural or pharmacological agents may be administered as injections or in the form of oral supplements. Injections provide the advantage of better bioavailability by avoiding enzymes in the gastrointestinal tract. In addition, injections may be especially beneficial in individuals with gastrointestinal absorption issues.
The lipotropic agents in this injection are methionine and choline. While each may individually affect the mobilization of fats, the combination may provide synergistic benefits. The physiological role of each compound and the effects of supplementation are described below.
Methionine is a sulfur-containing branched-chain amino acid. A precursor for cellular methylation reactions, methionine plays an important role in lipid metabolism, polyamine synthesis, immune function, heavy metal chelation, and maintenance of redox balance. Conversely, dietary methionine restriction in rodents increased energy expenditure, improved insulin resistance, and enhanced lipolysis and fatty acid oxidation in adipose tissue.
The lipotropic effects of methionine may be attributed to its metabolite S-adenosyl methionine (SAM). SAM is synthesized from methionine via an energy-consuming reaction. SAM administered orally or by injection has been investigated as a treatment for liver diseases, osteoarthritis, and depression. The benefits bestowed by SAM may be due to its role as a methyl donor in biochemical processes governing lipid homeostasis, DNA stability, gene expression, and neurotransmitter release.
Choline is an essential nutrient required for optimal functioning of various tissues including the liver, muscles, and brain. Since choline breaks down fat as an energy source, choline supplementation caused rapid fat and weight loss in female athletes. Only small amounts of choline are synthesized by the human body, necessitating its intake from external sources. In the body, about 95% of the total choline pool is converted to phosphatidylcholine – an essential component of the phospholipid bilayer and the predominant phospholipid in most mammalian cells. Choline also undergoes acetylation to form the neurotransmitter acetylcholine. Choline deficiency causes hepatic steatosis (fatty liver disease) and leads to loss of muscle membrane integrity. Chronic choline deficiency may also increase the risk of developing cancer.
Both choline and methionine are a source of methyl groups for the one-carbon transmethylation pathway and serve hepato-protective functions. Culturing hepatocytes in choline and methionine-deficient media impaired VLDL secretion. In addition, choline can donate methyl groups to support methionine regeneration, possibly contributing to their synergistic lipotropic effects.