Trimethylglycine or TMG is an amino acid found in various food sources, particularly beets (hence the alternative name of betaine), quinoa, and spinach. It’s also naturally produced in the liver. TMG contains three methyl groups and functions very closely with other nutrients like choline, folic acid, and vitamin B12.
TMG has two major functions in the body. The first one is to act as a methyl donor – influencing various bodily processes such as detoxification, liver health, and protein metabolism – and the other is to promote fluid balance which is critical for cell growth.
Apart from its basic roles, TMG has also been studied for its potential effects on physical performance, power output, energy, and muscle growth. These effects have made TMG a trendy ingredient in many gym supplements, often included in the form of betaine anhydrous.
Homocysteine is an amino acid found in blood and has been linked to higher risks of heart disease. Trimethylglycine helps lower the levels of homocysteine. Lowering homocysteine levels has been linked to lower risks of heart disease and strokes as high levels of homocysteine can cause arterial plaque formation which causes our arteries to harden and get clogged. 
The stomach has to have the right level of acidity to digest food properly. If your acid levels are low, the body will not be capable of breaking down food and absorbing its nutrients. This can increase the risk for nutrient deficiencies as well as problems like bloating, acid reflux, constipation, and indigestion.
TMG in the form of Betaine HCl has been shown to help improve symptoms in volunteers with low acidity. Moreover, maintaining stomach acidity can also lead to healthier digestion as well as a more efficient nutrient absorption. 
Betaine HCI when taken as a digestive supplement promotes the production of additional hydrochloric acid in the stomach, which aids digestion, assists with the absorption of b12, calcium, iron and proteins.
Symptoms of obesity, alcohol abuse, and even diabetes can cause a massive uptick of fatty acid build up in the liver. While the liver naturally retains some fat, especially as an extra energy reserve in case of famine, too much can lead to fatty liver disease. [3, 4]
Studies show supplementing with TMG can help reduce the amount of fatty acids broken down by the liver. In turn, this reduces fatty acid accumulation. Some scientists also note how some patients have recovered from liver damage by taking TMG. 
An ergogenic is an ingredient or substance supplemented to improve physical performance, recovery, or stamina.
TMG is right up there with some of the recently trending ergogenics in formulas and with good reason. Studies demonstrate TMG’s ability to boost muscle power, endurance, and even promote muscle protein synthesis – the very process required to put on lean mass. It’s also been shown to accelerate fat loss, especially in obese patients. 
One little known benefit of taking TMG is increasing our body’s S-adenosylmethionine (SAMe) production.
SAMe is a component required in the synthesis of Phosphatidylcholine. Phosphatidylcholine is a compound mainly known for its brain health and cognitive benefits. Other than brain health, SAMe can also be a mood enhancer, boost liver health, and support joint health and recovery. 
As we mentioned earlier, TMG is a molecule with three methyl groups. These methyl groups are passed around inside the body through a process known as methylation. Methylation is critical for many physiological processes, and the most important is the methylation of homocysteine to form methionine.
Balancing fluid levels is vital for human survival as fluid imbalances can cause shrinking or bloating of cells, causing internal tissue or organ damage. TMG can act as an osmolyte, a compound or substance that functions to balance fluid levels inside and outside of cells. 
TMG is a naturally occurring substance in the body that can also be consumed through beets, spinach, and quinoa. TMG’s role in the body are primarily for cellular fluid balance and methylation, but there are also benefits to supplementing TMG. Research has proven the benefits of supplementation for heart health, detoxification, muscle growth, and healthy digestion. It can also act as an ingredient that supports creatine levels in the body, boosting power output and delaying fatigue during exercise.