Also known as: Betaine hydrochloride, Trimethylglycine HCl, Stomach acid support
FoundationalEmerging evidence
A source of hydrochloric acid used to support stomach acidity during digestion. Regularly confused with betaine anhydrous, the performance ingredient, and the two do entirely different jobs.
Typical dose
300.0–1500.0 mg per day
At the start of a protein-containing meal, never on an empty stomach
What it is
Betaine HCl is betaine bound to hydrochloric acid. When it dissolves in the stomach it releases that acid, which is the entire purpose of the product.
Betaine anhydrous, also called TMG, is the performance ingredient taken at 2.5 g for power output and training volume. Betaine HCl is taken at similar milligram weights for digestion.
Buying one expecting the other is a common and expensive mistake. If a pre-workout lists betaine, it should be the anhydrous form; if a digestive product lists it, it should be the HCl.
How it works
Stomach acid does several things: it activates the enzyme that begins protein digestion, releases minerals such as iron and zinc from food, and acts as a barrier to organisms arriving with a meal.
Betaine HCl supplies hydrochloric acid directly, temporarily lowering stomach pH during a meal.
That is only useful if your stomach acid is genuinely low, which becomes more common with age. In someone producing normal amounts, adding more achieves nothing and may cause discomfort.
What the evidence shows
Research has confirmed that betaine HCl does lower stomach pH, including in people whose acid production has been reduced by medication, which establishes that the mechanism works as described.
There is also evidence that it improves absorption of certain compounds that depend on an acidic stomach.
Beyond that, the evidence base is small. Trials showing it improves digestive symptoms in ordinary users are limited, and the self-testing protocols circulating online have no research support at all.
Dosing
Typical products supply 300 to 750 mg per capsule, taken at the start of a protein-containing meal.
Take it with food and never on an empty stomach. This is a genuine warning rather than a formality, since concentrated acid without a meal to buffer it causes real discomfort.
Stop and seek advice if you feel warmth or burning. The escalating-dose self-tests promoted online involve deliberately provoking that sensation, which is a poor idea and has no evidence behind it. If digestion is a persistent problem, that warrants a proper assessment rather than self-experimentation.
At a glance
Common forms
Betaine HCl capsules, Combined with pepsin, Within digestive formulas
Half-life / duration
Acts during the meal only
Timing
At the start of a protein-containing meal, never on an empty stomach
Competition status
Permitted — not on the WADA Prohibited List
Category
Foundational
Safety and side effects
The main risk is irritation. Betaine HCl supplies concentrated acid, and taking it without food, or taking too much, causes burning and discomfort.
Anyone who has been told they have irritation or ulceration of the stomach or gullet should avoid it entirely, as should anyone taking medication that reduces stomach acid, since the two work against each other.
Avoid it alongside anti-inflammatory painkillers, which are themselves hard on the stomach lining. Speak to your doctor before use if you take regular medication.
Who should avoid it
Avoid entirely if you have been told you have irritation or ulceration of the stomach or gullet. Avoid if you take medication that reduces stomach acid, or alongside anti-inflammatory painkillers. Never take on an empty stomach. Stop and seek advice if you feel burning. Speak to your doctor before use if you take regular medication.
This entry is provided for information only. Food supplements should not be used as a substitute for a varied and balanced diet and a healthy lifestyle. Consult a qualified healthcare professional before use if you are pregnant, breastfeeding, taking medication or under medical supervision.
