Acid for Digestion

Stomach acid – hydrochloric acid or HCL – is essential for good digestion. It promotes the breakdown of proteins, it’s essential for optimal absorption of certain minerals, and it forms a barrier against bacterial and fungal pathogens that might otherwise enter the intestine through the nose or mouth. Absence of stomach acid (achlorhydria) or too little stomach acid (hypochlorhydria) results in nutrient deficiencies and imbalances in the intestinal microflora, which can lead to a host of serious disorders. Conditions associated with low stomach acid include the following:

(Note: These conditions can also result from other causes.)

  • Anemia, iron deficiency
  • Asthma
  • Bad breath
  • Bacterial overgrowth in the stomach and small intestine
  • Chronic autoimmune disorders (e.g. rheumatoid arthritis, lupus)
  • Chronic Candida infections
  • Depression
  • Diabetes, type 1
  • Digestive disturbances, indigestion, bloating, constipation
  • Food allergies and sensitivities
  • Gallbladder disease
  • Gallstones
  • GERD
  • Heartburn
  • Grave’s disease
  • Osteoporosis
  • Pernicious anemia
  • Rosacea
  • Skin diseases, including forms of acne, dermatitis, eczema, and urticaria (hives)
  • Stomach cancer
  • Vitiligo
  • Weak, chipping, or peeling fingernails

Unfortunately, people often mistake too little stomach acid for too much stomach acid. Feeling uncomfortable after eating—gas, bloating, belching, heartburn—is even called “acid indigestion,” when in fact it is nearly always caused by too little stomach acid rather than too much. It is poor digestion in the stomach (perhaps combined with bacterial overgrowth) that creates pressure and causes the aforementioned symptoms. Antacids (Tums®, Rolaids®, Mylanta®) and acid blockers (Zantac®, Pepcid®, Prevacid®, Protonix®) treat symptoms but don’t get to the root of the problem. Not correcting the problem can lead to nutritional deficiencies and the conditions mentioned above.

Even acid reflux (GERD) – the passage of acid from the stomach into the esophagus – is a result of too little stomach acid. GERD is caused not by excess acid production but by a weakness of the lower esophageal sphincter (LES) muscle, which fails to keep the acid where it belongs – in the stomach. In fact, testing has shown hypochlorhydria in 90 percent of severe GERD cases.[i] The stomach has mechanisms for protecting itself from this strong acid, whereas the esophagus does not. Hence, even a small amount of acid can do great harm to the esophagus. If you frequently experience acid reflux, you should find a medical doctor or naturopath who will help you with natural treatments. To find such a physician in your area, you can search the website of the American College for Advancement in Medicine (ACAM) at or the website of the Colorado Association of Naturopathic Physicians at or the national website of naturopathic physicians at

There is an accepted test, the Heidelberg test, to determine whether you have low (or excessive) stomach acid. It involves swallowing a capsule containing a high-frequency transmitter that measures stomach pH. You are then asked to drink a sodium bicarbonate solution, which will make the stomach alkaline. Stomach pH is then continuously monitored with the Heidelberg capsule to determine the time needed for the stomach to re-acidify. This test is not commonly conducted by most physicians and you would likely need to request it.

If the Heidelberg test is unavailable to you, there are a couple of low-tech “tests” that you can administer to yourself. One is the vinegar or lemon juice test. If you notice “indigestion” after a meal, swallow a tablespoon of apple cider vinegar or lemon juice. If it makes you feel better, it is likely that you are low in stomach acid. If it makes you feel worse, then low stomach acid is probably not your problem, and you shouldn’t take any supplemental HCL. (If the vinegar or lemon juice leaves you feeling uncomfortable, drink a large glass of water to dilute the acid, or neutralize the acid with ½ teaspoon of baking soda in a cup of water.) The other is the baking soda test. To perform this test mix one quarter teaspoon of baking soda in eight ounces of cold water, first thing in the morning, before eating or drinking anything except water. Drink the baking soda solution. Time how long it takes to belch. Time up to five minutes. If you have not belched within five minutes stop timing.

If your stomach is producing adequate amounts of hydrochloric acid you should probably belch within two to three minutes. Early and repeated belching may be due to excessive stomach acid. Belching results from the acid and baking soda reacting to form carbon dioxide gas.

If you know or think that you have low stomach acid, you can select one of the following ways to either stimulate stomach acid production or replace it.

Bitter herbs

Bitter herbs have been used for centuries to promote digestion. Bitter tasting herbs, such as fennel seed, gentian root, cardamom seed, wormwood, and astragalus root are thought to increase the flow of a variety of digestive juices, including saliva, HCL, bile, and pancreatic enzymes. They may also increase the tone of the LES muscle (the culprit in GERD).

“Bitters” are available in liquid form as combinations of several herbs. They are usually administered 10 to 30 minutes before eating by sipping or swallowing a counted number of drops (typically 15 to 30) in a small amount of water. Bitters are also reported to be effective if merely touched to the tongue. Tasting the bitterness seems to be the important factor. It is speculated that this response evolved to protect us from eating poisonous plants, which are often bitter.

Bitters are likely to work best for someone who still has acid-producing capacity (he or she is not achlorhydric).

Betaine hydrochloride

Betaine hydrochloride is a synthesized molecule that provides a safe way to deliver hydrochloric acid to the stomach. Betaine HCL is sold in capsules or tablets containing approximately 350 mg or 650 mg of betaine HCL. The greater part of the weight (about ¾) of the compound is betaine, and the remainder is hydrochloric acid. (Be sure to distinguish betaine HCL from anhydrous betaine, which has no HCL and is used for lowering homocysteine, not aiding digestion.)

Betaine HCL supplements often include pepsin, a protein-digesting enzyme that can function in an acid environment. Pepsin (or technically, its inactive precursor, pepsinogen) and stomach acid are secreted by different cell types in the stomach. It is presumed, though not proven, that when HCL secretion is inadequate, pepsin production is also inadequate. Hence, the inclusion of pepsin in betaine HCL supplements.

How much betaine HCL to take

Regarding how much betaine HCL to take, it is recommended that you start with one capsule or tablet of about 650 milligrams, early on in a sizeable, protein-containing meal. (Do not test with a small meal or one that consists only of fruit, a light salad, or a bowl of cereal.) Stop if you experience any stomach irritation, such as a stomach ache, heartburn, or a feeling of warmth or pressure in your stomach, and do not take any more HCL supplements. If you experience such a reaction, drink a large glass of water to dilute the acid or take ½ teaspoon of baking soda in a cup of water.

If taking the first capsule of betaine HCL does not aggravate your symptoms, continue to take one capsule with each similar-size meal for 2 or 3 days. Then increase to 2 capsules with each meal of similar size. If there is still no problem, increase to 3 capsules. (When taking several capsules, it is best to space them out over the meal.) Continue increasing the number of capsules in this manner until you notice a warm feeling in your stomach or you have reached 7 capsules, whichever comes first. If you notice a warm feeling, you have taken too many capsules and need to take one less for a meal of that size.

When you have found the largest number of capsules you can take without feeling warmth in your stomach, continue taking that amount with other similar-size meals. Take less for smaller meals.

With better digestion, your stomach may increase its production of acid over time, and you may begin feeling warmth in your stomach when you take the supplements. You should then reduce the number of capsules per meal.


HCL supplements such as betaine hydrochloride should not be taken by individuals with a current or past history of ulcers or those currently taking antacids or acid-blocking medications.


[i] Wright JV and Lenard L, Why Stomach Acid Is Good for You (M. Evans and Company, 2001), 130