What is the natural form of betaine?

November 15, 2025 •

3 min read

First isolated from sugar beets in the 19th century, betaine is a naturally occurring compound found in various plants, animals, and microorganisms. This nutrient, which is also known as trimethylglycine (TMG), exists in its most common and natural form as betaine anhydrous.

Quick Summary

The natural form of betaine is trimethylglycine (TMG), which exists most commonly as betaine anhydrous. It is naturally present in foods like spinach, sugar beets, and whole grains, where it functions as both an osmolyte and a methyl donor.

Key Points

Trimethylglycine (TMG) is Natural: The natural and most common form of betaine is trimethylglycine, also known as betaine anhydrous.
Sourced from Plants and Animals: Natural betaine is found widely in foods such as sugar beets, spinach, whole grains (like wheat bran), and seafood.
Dual Functionality: The two key roles of natural betaine are acting as a methyl donor and an osmolyte.
Differs from Betaine HCl: Natural betaine (TMG) is not the same as synthetic betaine HCl, which is an acidic compound used for stomach digestion.
Supports Cellular Health: As an osmolyte, betaine helps cells maintain their water balance, protecting them from environmental stress.
Important for Heart Health: As a methyl donor, betaine helps regulate homocysteine levels, which is important for cardiovascular health.

What Exactly is Betaine?

Betaine, or trimethylglycine (TMG), is a nutrient and amino acid derivative that plays several important roles in the human body. It is an essential component found in many living organisms, from plants and bacteria to animals. Structurally, betaine is the amino acid glycine with three methyl groups attached, which gives it its alternate name, trimethylglycine. This unique chemical structure is crucial for its primary functions as both a methyl donor and an osmolyte.

Trimethylglycine: The Natural and Endogenous Form

When people refer to the natural form of betaine, they are typically talking about trimethylglycine (TMG), which is also called betaine anhydrous. The term "betaine anhydrous" simply means betaine without water. This is the form found naturally in foods and is also the version used in FDA-approved prescription medications, such as Cystadane, for treating certain metabolic disorders. The body can also produce TMG internally from choline, making it a non-essential nutrient, but dietary intake is vital for maintaining optimal levels.

Primary Dietary Sources of Natural Betaine

TMG is readily available from a variety of whole foods. Including these in your diet can help ensure an adequate intake of this beneficial compound.

Vegetables and Fruits

Spinach: A top source of betaine, with high concentrations in both raw and cooked forms.
Beets: As its name suggests, betaine was first discovered in sugar beets and they remain a significant source, especially in raw and canned varieties.
Broccoli
Avocado

Grains and Cereal Products

Wheat Bran: One of the richest known sources of betaine.
Wheat Germ: Also contains a very high concentration.
Whole Grains: Whole wheat breads and other whole-grain products are good sources of betaine, though levels can vary and be reduced by processing.
Quinoa: Considered a pseudocereal, it is another excellent source.

Seafood

Shrimp: Contains a notable amount of betaine.
Clams, Mussels, and Oysters: Shellfish, in general, are good sources.

Natural Betaine Anhydrous vs. Synthetic Betaine HCl

When purchasing betaine supplements, it is important to distinguish between betaine anhydrous (the natural form) and betaine hydrochloride (HCl), a synthetic form used as a stomach acidifier.


Feature	Natural Betaine (TMG/Anhydrous)	Synthetic Betaine HCl
Source	Naturally extracted from plants like sugar beets	Synthetically produced via a chemical process
Chemical Form	A neutral, zwitterionic compound; not an acid	Hydrochloric salt of betaine; is an acid
Primary Function	Acts as a methyl donor and osmolyte	Used to increase stomach acid levels
Safety	Generally recognized as safe (GRAS) for consumption	Can cause stomach discomfort or irritation at high doses
Use Case	Supports cardiovascular health by lowering homocysteine; aids liver function; improves hydration	Aids digestion in individuals with low stomach acid, typically as a supplement for specific digestive issues

The Physiological Roles of Natural Betaine

Betaine performs two critical physiological functions within the body:

As an Osmolyte

Betaine helps cells maintain their water balance and protect them from osmotic stress caused by changes in water concentration. This is particularly important for kidney cells, which are exposed to high concentrations of salts. By protecting cells from dehydration, betaine helps maintain cellular function and protects against temperature or salinity-induced inactivation.

As a Methyl Donor

As a methyl donor, betaine provides a methyl group ($CH_3$) to aid in the remethylation of homocysteine to form methionine. This is a crucial step in the methionine cycle and is one of the ways the body regulates healthy homocysteine levels in the blood. Elevated homocysteine levels are associated with an increased risk of heart disease, so betaine's role in mitigating this risk is significant. This methylation process is also essential for creating important biomolecules like carnitine, creatine, and phospholipids.

Conclusion

What is the natural form of betaine? The natural form is trimethylglycine (TMG), also known as betaine anhydrous, and it serves as a powerful and stable compound with two main physiological roles: acting as a protective osmolyte and a crucial methyl donor. Found abundantly in foods like sugar beets, spinach, and whole grains, TMG is a vital nutrient for maintaining cellular function, supporting heart health by regulating homocysteine, and contributing to overall metabolic well-being. It's essential to recognize that this natural form differs significantly from synthetic betaine HCl, which is used to acidify the stomach, and to ensure you are getting the correct type for your nutritional needs. For more detail on betaine's role as a functional ingredient, read the analysis from the National Institutes of Health.

Frequently Asked Questions

The best food sources for natural betaine include wheat bran, wheat germ, spinach, beets, quinoa, and certain seafood like shrimp.

Yes, betaine and trimethylglycine (TMG) are often used interchangeably, as TMG is the full chemical name for the naturally occurring form of betaine. Betaine anhydrous is another term for this same compound.

Betaine is a neutral compound (trimethylglycine) that functions as a methyl donor and osmolyte. Betaine HCl is a synthetic, acidic form used primarily to increase stomach acid and aid digestion, and is chemically distinct from natural betaine.

Natural betaine's main physiological roles are to act as an osmolyte, helping cells maintain hydration, and as a methyl donor, which is vital for biochemical processes like converting homocysteine to methionine.

Yes, some studies indicate that cooking and processing, especially boiling, can lead to a significant loss of betaine content in certain foods. However, the nutrient remains stable under normal temperature ranges.

Yes, the human body can synthesize betaine from choline in the liver and kidneys. However, endogenous production is often insufficient to meet daily needs, making dietary intake crucial.

Natural betaine is associated with several health benefits, including supporting heart health by lowering homocysteine levels, protecting against liver disease, aiding athletic performance, and acting as an antioxidant.