Thorne Betaine HCL/Pepsin

Endurance athletes consume a lot of protein. The ability to actually digest and absorb it (aka getting what you actually think you are) depends on having enough stomach acid.

Hydrochloric acid (HCl) is the first domino in your digestive chain: it activates the enzyme that breaks down protein, kills pathogens in food before they reach your gut, keeps bacterial overgrowth in check, and triggers the release of bile and pancreatic enzymes further down the line. When HCl production falls short, protein digestion slows, nutrient absorption suffers, and symptoms like bloating, gas, and indigestion that athletes often attribute to their diet are actually rooted in inadequate stomach acidity.

Thorne Betaine HCL & Pepsin restores what's missing at the source.

Restart Your Digestive Chain – Betaine hydrochloride (betaine HCL) temporarily lowers the pH of the stomach, restoring the acidic environment needed for optimal protein digestion and nutrient absorption. A healthy stomach pH also activates the release of bile and pancreatic enzymes downstream — meaning better fat digestion and more complete extraction of the vitamins and minerals in every meal you eat.

Protein Digestion Activated – Pepsin is the enzyme that does the heavy lifting of protein breakdown, but it can only be activated in an adequately acidic stomach. Thorne pairs betaine HCL with porcine-sourced pepsin to ensure both the acid environment and the active enzyme are present simultaneously — giving your stomach everything it needs to fully process the protein you're eating, not just partially digest it.

Nutrient Absorption — Getting More From What You Eat – Low stomach acid quietly degrades your ability to absorb folate, vitamin B12, iron, zinc, magnesium, and calcium — micronutrients that endurance athletes depend on for energy production, oxygen transport, and recovery. Correcting the acid environment with betaine HCL addresses this at the root, so the supplements and food you're already consuming actually reach your tissues.

Hard training, NSAID use, antacid overuse, and normal aging all suppress HCL production over time. The result isn't just digestive discomfort — it's reduced protein utilization, compromised micronutrient absorption, and a gut environment that's less effective at filtering pathogens. Thorne's formula addresses this with a clean two-ingredient approach: betaine hydrochloride and porcine pepsin, nothing unnecessary added.

How to Use Thorne Betaine HCL & Pepsin

Dosage: Take 1–2 capsules with each meal, or as recommended by your healthcare practitioner. The capsules work during active digestion — taking them at the beginning or middle of a meal gives the HCL time to lower stomach pH while food is present.

Dose Assessment: Because HCL needs vary by individual and meal size, some practitioners recommend starting with 1 capsule per meal and increasing by 1 capsule per meal until you feel a mild warmth in your stomach — then stepping back to the dose just below that threshold. Always do this cautiously and ideally under practitioner guidance.

Pro Tip: Do not open the capsule or crush it — betaine HCL powder is highly irritating to the mouth and esophagus. Always swallow whole.