POTS (postural orthostatic tachycardia syndrome) management typically calls for 5,000–10,000 mg of sodium per day, which is 2–4× the standard dietary recommendation and essentially impossible to hit through food alone without a deliberate strategy. Commercial electrolyte products (Liquid IV, LMNT, Pedialyte) either cap sodium well below therapeutic range, cost $1–1.50 per serving, or are too sweet to drink two or three times daily for months on end. This is a homemade oral rehydration solution built from first principles to hit POTS-therapeutic sodium and potassium targets at 3 drinks per day, at roughly $0.46 per drink. This note covers the recipe, why each ingredient is there, and the chemistry behind the design.
The short answer is that the gut can’t absorb sodium efficiently without it.
Sodium-glucose cotransporter 1 (**SGLT1**) is a protein on the brush border of the jejunum that actively transports sodium into the gut wall. The transporter uses 2 Na⁺ ions per 1 glucose molecule — the energy released by sodium moving down its electrochemical gradient drives glucose uphill into the enterocyte, and the basolateral Na⁺/K⁺-ATPase pump restores the gradient continuously.
The counterintuitive part: the direct 2:1 co-transport is actually the _minority_ of the sodium absorption. The dominant mechanism (~66–80%) is **passive solvent drag**. SGLT1 activity creates an osmotic gradient that pulls water transcellularly into the enterocyte, and that bulk fluid flow carries sodium passively through the gaps between cells (the paracellular pathway). Glucose doesn’t just ride along — it’s the trigger for the entire system.
Without glucose, SGLT1 doesn’t run. Without SGLT1, there’s no osmotic gradient. Without the gradient, there’s no solvent drag. Sodium absorption reverts to slow, inefficient passive diffusion. This is why adding electrolytes to plain water is not the same as drinking ORS — the water empties from the stomach quickly (it’s completely hypotonic), but once in the small intestine, the sodium just diffuses across at a fraction of the SGLT1-driven rate.
This mechanism is why oral rehydration therapy works. Historical cholera case fatality rates ran 25–50% before ORT; with appropriate ORS treatment, the WHO reports CFR below 1%. It’s also why the glucose in this recipe isn’t optional.
Not all sugars drive SGLT1 equally. The transporter accepts glucose and galactose. It does not accept fructose.
**Sucrose** (table sugar, the sugar in Gatorade) is a glucose-fructose disaccharide. The enzyme sucrase splits the glucose and fructose before absorption. The glucose half enters via SGLT1. The fructose half uses GLUT5, which has no sodium co-transport. For ORS purposes, fructose is inert — it contributes calories and dental exposure without driving sodium absorption.
**Dextrose**, or dextroglucose, is pure right-handed glucose, the only form of glucose the body can use. 1 g dextrose = 1 g SGLT1-active glucose. 1 g sucrose = 0.5 g SGLT1-active glucose.
This means using sucrose as your sole glucose source requires twice the sugar mass for the same SGLT1 effect. The Gatorade in this recipe is 100% sucrose. If you tried to eliminate the dextrose and cover all SGLT1 glucose needs with Gatorade alone, the algebra works out to ~30 g Gatorade powder — which raises total sugar from 15.56 g to ~23 g per drink and nearly triples the wasted fructose. Dextrose is the efficient glucose source; Gatorade’s job is flavor.
The WHO has been formulating ORS since the 1970s, and the evolution of those formulas is directly relevant here.
The **1975 formulation** was designed for cholera. It used 90 mmol/L sodium and 111 mmol/L glucose, for a total osmolarity of 311 mOsm/L. The Na:glucose solution ratio was approximately 1:1.23.
The problem: at high glucose concentrations, SGLT1 saturates and unabsorbed glucose remains in the gut lumen. That glucose creates an osmotic gradient that draws water _back_ into the lumen — osmotic diarrhea. Clinical trials in the 1990s showed the 1975 formula increased stool volume by up to 36% in non-cholera patients and worsened dehydration in some cases.
The **2002 reduced-osmolarity formulation** dropped to 75 mmol/L sodium and 75 mmol/L glucose, for 245 mOsm/L total. The Na:glucose solution ratio became exactly 1:1. The lower osmolarity reduced osmotic diarrhea and improved outcomes. This is now the WHO standard.
Note that the solution ratio (1:1) and the transporter stoichiometry (2:1 Na:glucose) are different things. At 1:1 in solution, there’s already twice as much glucose as the transporter strictly needs — SGLT1 is glucose-saturated. The WHO reduced the solution ratio to cut osmolarity, not because they reached a glucose floor.
This recipe sits at a Na:glucose solution ratio of **1:1.24** — above the 2002 WHO target and nearly identical to the original 1975 formula. The research-optimal for pure sodium absorption is closer to 1:2 (glucose:Na = 2:1), but that’s a different goal. WHO optimized for _water retention in sick patients_. This recipe optimizes for _sodium delivery in a healthy gut_. The 2002 reduction was clinically appropriate for cholera wards; it’s not load-bearing for POTS use.
Per 30 oz (887 mL), measured by weight:
| Ingredient | Amount | Na | K | Sugar |
|---|---|---|---|---|
| Kirkland Sea Salt (NaCl) | 2,500 mg | 983 mg | — | — |
| NOW Potassium Citrate Powder | 2,500 mg | — | 800 mg | — |
| Gatorade Lower Sugar Powder | 11 g | 183 mg | 61 mg | 8.56 g sucrose |
| Dextrose | 7 g | — | — | 7 g glucose |
| **Total** | **1,166 mg** | **861 mg** | **15.56 g** |
**2,500 mg NaCl (Kirkland Sea Salt)**
This is the primary therapeutic ingredient. At 39.34% sodium by mass, 2.5 g delivers 983 mg Na. The remaining 183 mg comes from Gatorade. Total sodium per drink: 1,166 mg.
The 2.5 g target was derived backward from the daily goal. POTS sodium target is 5,000–10,000 mg/day. Food on a ration-forward diet averages roughly 2,000–4,000 mg/day. To reliably reach the therapeutic floor at 3 drinks/day: 3 × 1,166 = 3,498 mg Na from ORS, plus food = 5,500–7,500 mg total. That lands mid-range in the POTS therapeutic window.
**2,500 mg NOW Potassium Citrate Pure Powder**
High sodium intake is not metabolically neutral with respect to potassium. Elevated sodium stimulates aldosterone secretion, and aldosterone drives urinary potassium excretion. Running a high-sodium POTS protocol without potassium replacement risks secondary hypokalemia. The potassium in this recipe isn’t optional — it’s safety-adjacent.
Potassium also has a second effect that partially offsets the pressor cost of therapeutic sodium loading: it promotes urinary sodium excretion (natriuresis) and causes mild vascular relaxation. At this recipe’s K:Na ratio of ~0.74:1 per drink, this dampens the BP effect but does not neutralize it. True K:Na parity would require roughly doubling the potassium dose — beyond the recipe’s design purpose, and past ~4,000–5,000 mg/day supplemental K, periodic serum monitoring is prudent for anyone without confirmed normal kidney function. For healthy kidneys there is no formal upper limit on dietary potassium; the kidneys excrete excess efficiently. The concern is primarily CKD or medications that impair K excretion (ACE inhibitors, ARBs, potassium-sparing diuretics).
The amount is derived from the hypokalemia prevention target. Potassium RDA is 3,400 mg/day. Food on a ration-forward diet averages roughly 1,070 mg/day. To reach RDA at 3 drinks/day: need ~2,330 mg K from ORS → 861 mg/drink → 800 mg from citrate + 61 mg from Gatorade. At 3 drinks, ORS delivers 2,583 mg K; plus food baseline lands at ~3,650 mg/day, slightly above RDA.
The choice of **potassium citrate** over potassium chloride (KCl) has two reasons. First, KCl tastes metallic and bitter at high doses; at therapeutic K loads this is a compliance problem. Citrate is noticeably milder. Second, KCl can irritate the gastric mucosa at high concentrations; citrate has better GI tolerance. The potassium bioavailability is similar either way.
This product (NOW Potassium Citrate Pure Powder) pack-verified at 32% K by mass — slightly below the theoretical 36.2% for pure monohydrate, probably due to hydration state or excipients. Use the label’s ratio for recipe math, not theoretical chemistry.
**11 g Gatorade Lower Sugar Thirst Quencher Powder**
Gatorade’s primary role is palatability. Plain electrolyte solution — salt, potassium salt, and dextrose in water — is drinkable but austere. A small amount of Gatorade makes it taste like a sports drink.
The **Lower Sugar** variant was chosen primarily to minimize fructose. As established above, fructose doesn’t drive SGLT1 — it’s inert for sodium absorption purposes and just contributes osmotic load and dental exposure. Lower Sugar Gatorade has less sucrose per gram than regular, and its higher sodium density (16.67 mg Na/g vs. ~6.5 mg/g for regular) means only 11 g is needed to reach the target Na contribution — vs. ~28 g of regular Gatorade for the same Na. At 11 g, the sucrose load is 8.56 g (4.28 g of wasted fructose); at 28 g of regular, it would be substantially higher. The cost difference is marginal. The fructose reduction is the reason.
11 g of Lower Sugar Gatorade contributes 183 mg Na, 61 mg K, and 8.56 g sucrose. That sucrose provides 4.28 g of SGLT1-active glucose after hydrolysis.
11 g provides acceptable flavor. Downward experimentation is possible, especially as the citrate adds some flavor character of its own. Increasing to 15–20 g improves taste but raises sugar; if you bump it, recalculate the dextrose to avoid over-shooting the osmolarity ceiling (see below).
**7 g Dextrose**
Dextrose is the primary SGLT1 glucose source. 7 g contributes 38.9 mmol of glucose directly, compared to Gatorade’s 23.8 mmol (after accounting for sucrose’s 50% SGLT1 efficiency).
Combined SGLT1-active glucose: 62.7 mmol. Sodium: 50.7 mmol. Na:glucose solution ratio: 1:1.24.
WHO-exact (1:1) would require 5 g dextrose. 7 g slightly overshoots but stays within the SGLT1-saturated window and tastes marginally better. If minimizing sugar is a priority, dropping to 5 g costs nothing therapeutically — SGLT1 is glucose-saturated either way.
| Metric | Per drink | 3 drinks/day | + food baseline | vs. target |
|---|---|---|---|---|
| Sodium | 1,166 mg | 3,498 mg | 5,500–7,500 mg | 5,000–10,000 mg ✓ |
| Potassium | 861 mg | 2,583 mg | ~3,650 mg | 3,400 mg RDA ✓ |
| Sugar | 15.56 g | 46.7 g | — | — |
| Calories | 65 | 195 | — | — |
| Fluid | 30 oz | 90 oz (~2.7 L) | — | 2–3 L target ✓ |
This recipe at 30 oz works out to approximately **218 mOsm/L** — meaningfully hypotonic relative to WHO’s 245 mOsm/L and blood plasma at ~290 mOsm/L.
This matters if you want to concentrate the recipe into a smaller volume. The relevant threshold is isotonic (~290 mOsm/L): above that, the drink is hypertonic, gastric emptying slows, and the osmotic gradient can work against absorption. Mild hypotonicity is not an asset to preserve — isotonic is actually the absorption sweet spot (no equilibration step needed). Hypotonicity at current levels is simply neutral, not beneficial.
| Volume | Estimated osmolarity | Assessment |
|---|---|---|
| 30 oz (current) | ~218 mOsm/L | hypotonic, fast gastric emptying |
| 24 oz | ~272 mOsm/L | near-isotonic, optimal absorption |
| 20 oz | ~327 mOsm/L | mildly hypertonic, GI tolerance usually fine |
| 16 oz | ~408 mOsm/L | too hypertonic, not recommended |
20 oz is a practical lower bound. The 30 oz default isn’t about absorption efficiency — it’s about hitting the daily fluid target (2–3 L) through the ORS itself rather than requiring separate plain water to make up the difference.
| Ingredient | Purchased | $/g | Per drink | Per day (3×) |
|---|---|---|---|---|
| Kirkland Sea Salt | $3.99 / 850 g | $0.0047 | $0.01 | $0.04 |
| NOW K Citrate | $11.63 / 340 g | $0.0342 | $0.09 | $0.26 |
| Gatorade Lower Sugar | $25.44 / 1,650 g | $0.0154 | $0.17 | $0.51 |
| Dextrose | $11.99 / 454 g | $0.0264 | $0.19 | $0.56 |
| **Total** | **~$0.46** | **~$1.37** |
At 3/day: ~$500/year. For comparison, Liquid IV (Amazon 16-pack $23.62 → $1.48/pack) runs $1,620/year at 3/day — but delivers only 500 mg Na per pack vs. 1,166 mg here; matching this recipe’s sodium output requires 2.3 packs per drink → ~$3,723/year. Dextrose and Gatorade together account for ~78% of the per-drink cost; K citrate’s $0.09 contribution is the palatability premium over KCl.