Sodium bicarbonateAmino Acid

• High-intensity exercise performanceLikely helps

  The International Society of Sports Nutrition's 2021 position stand concludes that 0.2–0.5 g/kg improves muscular-endurance work and high-intensity cycling, running, swimming and rowing [1]. It reaches the same conclusion for boxing, judo, karate, taekwondo and wrestling [1].
  
  The effect is best established for efforts lasting 30 seconds to 12 minutes. It holds for single and repeated bouts, and in both men and women [1].
  
  The mechanism is buffering — the salt raises blood bicarbonate and pH, offsetting hydrogen ions generated by anaerobic work, which may delay fatigue [1]. ^[1]

• Recovery between bouts in boxingPossibly helps

  A placebo-controlled study in elite male boxers gave 0.3 g/kg during a 75-minute passive recovery between two exhausting bouts [22].
  
  Blood pH rose 0.11 units and bicarbonate 8.8 mmol/L (26.3%) against a sodium-chloride placebo. Second-bout performance improved by 164 seconds, versus 73 seconds on placebo [22].
  
  That is one small study in a single athlete population, which is why it sits below the pre-exercise evidence. ^[22]

• How much of the gain is placeboPossibly helps

  The ISSN position stand itself flags that a portion of the measured ergogenic effect appears placebo-driven rather than physiological [1].
  
  So the real physiological effect size is smaller than the headline performance numbers imply. We are flagging that rather than resolving it. ^[1]

• Heartburn and acid indigestionLikely helps

  Relief of dyspepsia — heartburn, acid indigestion, upset stomach — is one of two FDA-approved oral indications, per StatPearls [2].
  
  This is the ordinary over-the-counter use, sold as baking soda or as effervescent antacid granules under a real FDA-regulated label [3]. ^[2]

• Urinary alkalinizationLikely helps

  The second FDA-approved oral indication, per StatPearls: raising urine pH to reduce drug crystallization in specific poisoning cases [2].
  
  The same alkalinization is used to lower the kidney toxicity of hemoglobin breakdown products during hemolytic reactions [2]. ^[2]

• Metabolic acidosis, given intravenouslyLikely helps

  By IV it is FDA-approved for acute and chronic metabolic acidosis in severe renal disease, diabetic ketoacidosis, circulatory shock and cardiac arrest [2].
  
  StatPearls notes routine bicarbonate is no longer recommended in cardiac arrest generally. It reserves it for arrest from hyperkalemia, tricyclic antidepressant overdose or metabolic acidosis [2].
  
  This is a clinician-administered hospital route. None of it carries over to a capsule you swallow. ^[2]

• Off-label hospital usesPossibly helps

  StatPearls lists two uses outside the FDA-approved set. Nebulized sodium bicarbonate has been used for chemical lung injury after chlorine gas inhalation [2].
  
  The other is IV sodium bicarbonate for QRS prolongation from tricyclic antidepressant overdose [2]. Both are inhaled or injected routes chosen by a clinician, not oral ones. ^[2]

• Kidney stones in chronic kidney diseasePossibly helps

  A 2021 poster from the BASE Pilot Trial (168 CKD patients) reported that 0.5–0.8 mEq/kg/day of oral sodium bicarbonate raised urinary pH by 0.77–0.97 [17].
  
  Urinary citrate-to-creatinine rose 108–146% against placebo, with no change in urinary calcium or phosphate [17].
  
  Its own lead investigator said the finding "shouldn't totally alleviate concerns about promoting calcium phosphate stones" and asked for further study [17]. This is conference-poster data from a secondary analysis, not a full peer-reviewed paper. ^[17]

• Powder or effervescent granulesAntacid use, and the cheapest way to reach a 0.

  Elemental content

  Pure sodium bicarbonate; 84 mg = 1 mEq

  Absorption

  Dissolved fully in water first; one labeled OTC dose is ½ teaspoon (2,616 mg)

  Best for

  Antacid use, and the cheapest way to reach a 0.3 g/kg sports dose [3]

• 325 mg and 650 mg tabletsRepeat dosing through the day at a measured amount

  Elemental content

  A 650 mg tablet gives 7.7 mEq each of sodium and bicarbonate

  Absorption

  Swallowed whole, with no dissolving step

  Best for

  Repeat dosing through the day at a measured amount [2]

• Enteric-coated capsulesAthletes with a history of stomach trouble.

  Elemental content

  Same salt, coated to pass the stomach intact

  Absorption

  GI discomfort hit 3 of 11 users, versus 7 of 11 on gelatin capsules at 0.3 g/kg

  Best for

  Athletes with a history of stomach trouble. ISSN cautions the sample was small, and that coating does not stop intestinal effects such as osmotic diarrhea [1]

• IV solutionsHospital correction of metabolic acidosis.

  Elemental content

  1.26% ready-to-use, plus 4.2%, 5%, 7.5% and 8.4%

  Absorption

  Given by a clinician, bypassing the gut entirely

  Best for

  Hospital correction of metabolic acidosis. The 8.4% form (1 mEq/mL) is the most hypertonic and is not intended for rapid administration in cardiac arrest [2]

• Stomach upset, scaling with dose

  At antacid doses the usual complaints are gas, burping and a full or bloated feeling [8].
  
  At sports doses the ISSN position stand names bloating, nausea, vomiting and abdominal pain as the most common, with incidence and severity rising roughly with the dose [1]. ^[1]

• Milk-alkali syndrome

  This is the serious one. Large amounts of calcium taken alongside an absorbable alkali such as sodium bicarbonate can produce hypercalcemia, metabolic alkalosis and acute kidney injury together [10].
  
  It was first described in the early 20th century in peptic-ulcer patients on the Sippy regimen [11]. That meant hourly milk and cream plus alkali, occasionally up to 6.5 g of sodium bicarbonate per hour [11].
  
  The modern version is high-dose calcium supplements plus regular antacid use. That is why anyone with raised blood calcium is told to stay away from it [6]. ^[10]

• Conditions that rule it out

  Caution or avoidance applies with congestive heart failure, edema, high blood pressure, kidney disease, liver disease, high blood calcium, high blood sodium, low blood potassium and urination problems [6][8][9].
  
  The reason is the sodium load — a single OTC antacid dose can carry 500–700+ mg of sodium [3][8].
  
  Anyone on a sodium-restricted diet is told to check with a doctor before using it [9]. StatPearls adds that significant clinical doses raise edema risk in people with cardiovascular disease [2]. ^[9]

• Pregnancy

  A peer-reviewed review of heartburn management in pregnancy says sodium bicarbonate antacids are "preferably avoided... as they may lead to fluid overload and metabolic alkalosis in the mother and foetus" [12].
  
  Drugs.com assigns it the older FDA Pregnancy Category C — risk cannot be ruled out [13]. Read that as a standing caution, not clearance. ^[12]

• A sports dose is not an antacid dose

  For a 70 kg adult the ergogenic protocols work out to roughly 14–35 g/day, far above the OTC antacid range [1].
  
  Those numbers come from exercise-performance trials rather than antacid labeling, and the two should never be read across [1][3]. ^[1]

• Spacing it from other oral medicines

  Mayo Clinic advises leaving 1 to 2 hours between sodium bicarbonate and any other oral medicine, since it interferes with how well they are absorbed [8].
  
  It also says not to take it alongside signs of appendicitis or gastrointestinal bleeding, which it may mask or worsen [8]. ^[8]

• Drugs it stops you absorbing

  By raising gastric pH it lowers absorption of tetracyclines (doxycycline, minocycline, tetracycline), fluoroquinolones such as levofloxacin and ciprofloxacin, and azole antifungals including itraconazole and ketoconazole [7][8].
  
  The same is documented for NSAIDs, aspirin and other salicylates, calcium and iron supplements, corticosteroids, HIV protease inhibitors (atazanavir, fosamprenavir) and memantine [7][8].
  
  StatPearls adds cefpodoxime proxetil, whose conversion to its active form slows, plus extended-release formulations such as methylphenidate [2][6]. ^[7]

• Drugs it raises in your blood

  Alkaline urine means the kidney reabsorbs more of certain drugs instead of clearing them.
  
  That raises blood levels of dextroamphetamine, methamphetamine, lisdexamfetamine and pseudoephedrine, and with them the risk of their side effects [2][6][8]. ^[2]

• Drugs it clears faster

  The same urinary alkalinization speeds elimination of chlorpropamide, an older diabetes drug, and of aspirin and other salicylates, which can weaken their effect [6].
  
  The mechanism cuts both ways. Clinicians use it deliberately in salicylate overdose — identical effect, opposite intent [2]. ^[6]

• Potassium-lowering combinations

  Sodium bicarbonate can lower blood potassium on its own.
  
  Paired with aminoglycoside antibiotics or loop diuretics, that raises the risk of clinically low potassium [6]. ^[6]

• IV incompatibilities, hospital only

  In solution it is chemically incompatible with norepinephrine and dobutamine [2].
  
  Mixed with calcium-containing parenteral fluids, it risks precipitation [2]. ^[2]

Not a nutrient you get from food in the ordinary sense. The kidneys generate and regulate blood bicarbonate themselves, without depending on dietary intake [2].

As an ingredient it reaches the diet mainly through baked goods — as baking soda, or inside baking powder — and through processed foods where it works as a processing aid [20][15].

The FDA recognizes it under 21 CFR 184.1736 and related sections as a leavening agent, pH-control agent, emulsifier and flavor adjuvant [20]. It is also swallowed directly, dissolved in water, as an OTC antacid [3].

Bicarbonate itself is in essentially all mineral water, at concentrations set by the local geology. A 2025 Nutrients review calls a water "bicarbonate-rich" at 600 mg/L or more, with studied waters running from about 677 mg/L to 7,700 mg/L [18].

Across sparkling bottled waters from 10 European countries, median bicarbonate ran from about 213 mg/L in Italy to 1,260 mg/L in Poland [19].

For exercise, ISSN's position stand puts a single dose 60 to 180 minutes before the event [1].

Later in that window seems to cost nothing. GI discomfort was lower at 180 minutes than at 60 or 120, even though blood bicarbonate rose about the same [1].

A separate study found side effects peaked around 90 minutes after ingestion — a poor moment to be competing [1].

Taking it with a high-carbohydrate meal (bread with fruit spread and cereal bars, 1.5 g carb/kg) produced the fewest GI symptoms versus taking it alone [1].

Multi-day loading splits the daily total into three portions taken with breakfast, lunch and dinner, for 3–7 days before the event [1].

The boxing recovery study dosed 0.3 g/kg about 10 minutes into a 75-minute break between bouts [22].

Antacid use has no schedule — it goes in when symptoms show, dissolved fully in water, up to every 2 hours within the daily cap [3]. Leave 1 to 2 hours between it and any other oral medicine [8].