Comparison guide
Betaine (TMG) or betaine HCl?
These share a name but do different jobs. Betaine (TMG) is taken in grams to lower homocysteine or for training, while betaine HCl is an acid capsule sold for digestion, and one cannot stand in for the other.
The options, compared
| Option | Evidence | Best for | The honest note | |
|---|---|---|---|---|
| Betaine (Trimethylglycine) | Limited evidence | Lowering homocysteine | Strong evidence for lowering homocysteine at 3–6 g/day, but strength and power benefits at 2.5 g/day are limited and it moderately raises total and LDL cholesterol. | View |
| Betaine HCl | Limited evidence | Not for self-diagnosed low acid | It briefly re-acidifies a suppressed stomach, but there are no randomized trials for bloating, reflux or poor digestion, and a 650 mg capsule supplies only about 400 mg of betaine. | View |
Our verdict
Pick by job: betaine (TMG) at around 2.5 g is the sports and homocysteine form, bearing in mind its cholesterol effect. Betaine HCl rests on very limited evidence for digestion and should be skipped with gastritis, ulcers, NSAIDs or prescribed acid suppression.