You need electrolytes for intermittent fasting, and the good news is most brands are safe to use during your fasting window. Of the 17 electrolyte brands in our comparison table, 14 contain zero sugar and won't break your fast. Three brands have 4–7 grams of sugar per serving, enough to trigger insulin and disrupt the benefits of fasting. Below, we ranked all 14 fasting-safe options by sodium content and cost per gram of sodium.
Do Electrolytes Break a Fast?
Electrolyte minerals (sodium, potassium, magnesium) contain zero calories. They don't trigger insulin and won't interrupt autophagy. What can break your fast is everything else in the product: sugar, dextrose, maltodextrin, or other caloric ingredients.
Research confirms that stevia does not significantly raise postprandial glucose or insulin levels compared to sucrose,[2] making stevia-sweetened electrolytes a safe choice during fasting windows.
The quick rule: if the label says 0g sugar, you're almost certainly fine. Here's how the most common sweeteners in electrolyte products stack up for fasting:
| Sweetener | Calories | Insulin Response | Fasting-Safe? | Used By |
|---|---|---|---|---|
| Stevia | 0 | None | Yes | 11 of 17 brands |
| Monk Fruit | 0 | None | Yes | Instant Hydration (w/ stevia) |
| Allulose | ~0.2/g | Minimal | Yes | Liquid IV (SF) |
| None | 0 | None | Yes | Vitassium (capsules) |
| Sugar (Sucrose) | 4/g | Significant | No | DripDrop, Hydrant |
| Dextrose | 4/g | Significant (fast-acting) | No | NormaLyte |
One borderline case: Nuun Sport tablets contain 1g of sugar (4 calories). Most fasting researchers consider anything under 5 calories too small to meaningfully disrupt a fast. If you follow a strict zero-calorie fasting protocol, skip Nuun during your fasting window and use it during your eating window instead.
How Much Sodium Do You Need While Fasting?
Fasting increases sodium loss. When insulin drops (which happens within hours of your last meal), your kidneys start excreting more sodium and water.[1] This is why people get headaches, lightheadedness, and fatigue during fasts. It's often sodium depletion, not hunger.
General guidance by fasting type:
- 16:8 intermittent fasting: 2,000–3,000mg total daily sodium. One or two electrolyte servings during your fasting window, the rest from food.
- Extended fasting (24h+): 3,000–5,000mg+ from supplements alone, since you're getting nothing from food. Spread across the day.
Early research on fasting and electrolytes found that sodium excretion is enhanced during the initial phase of fasting, declining progressively over several days.[3] More recent work suggests this fasting-induced natriuresis may involve sodium-glucose cotransporter mechanisms in the kidney.[4]
Potassium (1,000–3,500mg daily) and magnesium (300–500mg daily) also matter during fasting, but sodium is the mineral most people come up short on. A high-sodium electrolyte brand handles the biggest gap. If you're also low on potassium, look for brands with 200mg+ per serving like SALTT (415mg), Redmond Re-Lyte (400mg), or NormaLyte (393mg, though this one has sugar so it's eating-window only).
14 Electrolytes for Intermittent Fasting, Ranked
All 14 brands below contain 0g sugar (except Nuun at 1g) and won't break your fast. Sorted by cost per gram of sodium, the most useful metric for comparing value when sodium is the primary concern.
| Brand | Sodium | $/Serving | $/g Sodium | Sweetener | Form |
|---|---|---|---|---|---|
| Hydrate Pro | 1,000mg | $0.78 | $0.78 | Stevia | Tub/Scoop |
| Redmond Re-Lyte | 810mg | $0.75 | $0.93 | Stevia | Tub/Scoop |
| Vitassium | 500mg | $0.50 | $1.00 | None | Capsules |
| Zerolyte | 1,000mg | $1.20 | $1.20 | Stevia | Stick Pack |
| SALTT | 969mg | $1.17 | $1.21 | Stevia | Stick Pack |
| Santa Cruz Paleo | 800mg | $1.00 | $1.25 | Stevia | Tub/Scoop |
| LMNT | 1,000mg | $1.50 | $1.50 | Stevia | Stick Pack |
| Nuun Sport | 300mg | $0.52 | $1.73 | Stevia | Tablet |
| Thorne Daily | 480mg | $1.33 | $2.77 | Stevia | Stick Pack |
| Key Nutrients | 110mg | $0.33 | $3.00 | Stevia | Tub/Scoop |
| Liquid IV (SF) | 500mg | $1.56 | $3.12 | Allulose | Stick Pack |
| Instant Hydration | 500mg | $1.60 | $3.20 | Stevia/Monk Fruit | Stick Pack |
| Ultima Replenisher | 55mg | $0.53 | $9.64 | Stevia | Tub/Scoop |
| Nectar | 100mg | $1.06 | $10.60 | Stevia | Stick Pack |
Data verified against manufacturer websites. Prices as of March 2026. See the full 17-brand comparison →
Where the value drops off: The top 7 brands deliver 500mg+ sodium per serving for under $1.55/g sodium. Below that, you're either paying a lot more per gram of sodium (Liquid IV, Instant Hydration) or getting very little sodium per serving (Key Nutrients at 110mg, Ultima at 55mg, Nectar at 100mg). Those low-sodium brands are fasting-safe, but you'd need many servings to reach a meaningful sodium intake.
3 Brands That Will Break Your Fast
These three brands use real sugar (sucrose or dextrose) as part of an oral rehydration solution (ORS) formula. The sugar activates sodium-glucose cotransport in the gut, which improves absorption but also triggers insulin. Use these during your eating window if you like them, but avoid them during fasting.
| Brand | Sodium | Sugar | Calories from Sugar | $/Serving |
|---|---|---|---|---|
| DripDrop | 330mg | 7g | ~28 cal | $1.01 |
| NormaLyte | 862mg | 6.75g | ~27 cal | $1.33 |
| Hydrant | 260mg | 4g | ~16 cal | $1.50 |
Data verified against manufacturer websites. Prices as of March 2026. See the full 17-brand comparison →
When to Take Electrolytes During Your Fast
During your fasting window (typically morning): Use any of the 14 fasting-safe brands. Add a serving to your morning water and sip throughout. If you're doing 16:8, one or two servings during the fasting window handles the sodium gap. Capsules like Vitassium work well here if you don't want flavored water while fasting.
During your eating window: Any brand works, including the sugar-containing ones. Your body also absorbs sodium from food, so supplements during this window fill gaps rather than carrying the whole load. If you prefer an ORS formula like NormaLyte for better absorption, the eating window is the time to use it.
A simple daily routine for 16:8 intermittent fasting: one electrolyte serving first thing in the morning (fasting-safe brand, 500–1,000mg sodium), normal food-based sodium during your eating window, and a second serving in the evening if you exercise or feel depleted. Most people doing standard IF don't need the same aggressive sodium supplementation as, say, POTS patients or extended fasters. One or two servings of a high-sodium brand usually covers it.
The Bottom Line
14 of 17 electrolyte brands in our comparison are fasting-safe. The three to skip during fasting (DripDrop, NormaLyte, Hydrant) all contain sugar that triggers insulin. Everything else uses stevia, monk fruit, allulose, or no sweetener at all.
For the best value during fasting, Hydrate Pro delivers the most sodium for the least money ($0.78/g sodium, 1,000mg per serving). If you want stick packs for portability, Zerolyte ($1.20/serving, 1,000mg) and SALTT ($1.17/serving, 969mg) are the best options. If you prefer capsules with no taste or mixing, Vitassium ($0.50/serving, 500mg) is the only option in our comparison.
Compare all 17 brands side by side in our full comparison table.
References
- DeFronzo RA, Cooke CR, Andres R, Faloona GR, Davis PJ. "The effect of insulin on renal handling of sodium, potassium, calcium, and phosphate in man." The Journal of Clinical Investigation, 1975; 55(4):845–855. pmc.ncbi.nlm.nih.gov
- Anton SD, Martin CK, Han H, Coulon S, Cefalu WT, Geiselman P, Williamson DA. "Effects of stevia, aspartame, and sucrose on food intake, satiety, and postprandial glucose and insulin levels." Appetite, 2010; 55(1):37–43. pmc.ncbi.nlm.nih.gov
- Weinsier RL. "Fasting — a review with emphasis on the electrolytes." American Journal of Medicine, 1971; 50(2):233–240. pubmed.ncbi.nlm.nih.gov
- Heyman SN, Bursztyn M, Szalat A, Muszkat M, Abassi Z. "Fasting-Induced Natriuresis and SGLT: A New Hypothesis for an Old Enigma." Frontiers in Endocrinology, 2020; 11:217. pmc.ncbi.nlm.nih.gov