Fasting strips glycogen stores and flushes water-soluble minerals, leaving you with brain fog, muscle cramps, and that hollow, shaky feeling that derails even the most disciplined fast. The difference between suffering through a 36-hour window and coasting through it comes down to one thing: the precise sodium-potassium-magnesium balance in your water. A good electrolyte mix replaces what urine excretion takes, without triggering an insulin spike or breaking your fast.
I’m Mohammad — the founder and writer behind ProteinJug. I’ve spent years analyzing supplement formulations, parsing third-party lab results, and comparing electrolyte ratios across dozens of brands to identify which products actually deliver meaningful mineral loads without hidden sugars or fillers.
This guide breaks down the five most effective electrolytes for fasting, ranked by their mineral density, ingredient purity, and real-world performance during extended fasts.
How To Choose The Best Electrolytes For Fasting
Not every electrolyte product is built for fasting. Many are designed for post-workout recovery and pack 10–20 grams of sugar per serving, which immediately breaks a fast. You need a formula that delivers serious mineral content — especially sodium — without insulin-triggering calories.
Sodium: The Non-Negotiable Baseline
During a fast, your kidneys excrete more sodium than usual. A serving providing at least 800–1,000 mg of sodium helps maintain blood volume, prevents orthostatic hypotension (dizziness when standing), and keeps energy stable. Products below that threshold are better suited for daily maintenance, not fasting.
Zero Sugar, Zero Loopholes
Scan the ingredient list for maltodextrin, dextrose, or natural flavors that contain hidden sugars. Some “zero sugar” products still use sugar alcohols or artificial sweeteners that can trigger a cephalic phase insulin response in sensitive individuals. Stevia and monk fruit are generally considered fasting-safe.
Potassium and Magnesium Balance
A good fasting electrolyte delivers potassium in the 200–400 mg range and magnesium around 60–180 mg per serving. Too little potassium leaves you prone to cramps; too much magnesium (especially magnesium citrate) can cause loose stools, which is counterproductive during a fast.
Quick Comparison
On smaller screens, swipe sideways to see the full table.
| Model | Category | Best For | Key Spec | Amazon |
|---|---|---|---|---|
| LMNT Zero Sugar | Premium | High-sodium needs | 1000mg Sodium per stick | Amazon |
| Ultima Replenisher | Mid-Range | Low-sodium preference | 6 electrolytes + vitamin C | Amazon |
| SALTT Ultra Variety (Keto Chow) | Premium | Complete mineral profile | 968mg Sodium, 409mg Potassium | Amazon |
| Keto Chow SALTT Fruit Variety | Premium | Fruit flavor variety | 969mg Sodium, 409mg Potassium | Amazon |
| REDMOND Re-Lyte Variety | Premium | Trace minerals from salt | 2:1 sodium-potassium ratio | Amazon |
In‑Depth Reviews
1. LMNT Zero Sugar Electrolytes – Variety Pack
LMNT delivers a full 1,000 mg of sodium per stick pack — the highest among the products reviewed here and exactly what your body craves during a fast. The 200 mg of potassium and 60 mg of magnesium round out a science-backed ratio that prevents cramps, brain fog, and the lightheadedness that hits around hour 20 of a water-only fast. Users consistently report sustained energy levels without the crash that comes from sugar-spiked alternatives.
The flavor profile leans sweet (despite zero sugar) because of the stevia and natural flavors, though some find it too sweet and dilute with extra water. The variety pack includes flavors like Citrus Salt, Raspberry Salt, and Watermelon Salt, all of which mix cleanly without clumping. LMNT has become the default recommendation in the fasting community for a reason — it works reliably when other products fall short.
One minor friction point: the cost per serving is higher than most competitors, which adds up during long-term daily use. But for the specific scenario of extended fasting, the sodium density and clean ingredient list make it the most effective option on the shelf.
Why it’s great
- Highest sodium per serving (1,000 mg) — ideal for fasting losses
- Zero sugar, no maltodextrin, no artificial aftertaste
Good to know
- Sweetness level may be too strong for some; dilute with more water
- Premium price per stick compared to mid-range options
2. Ultima Replenisher Daily Electrolyte Powder – Variety Pack
Ultima Replenisher takes a different approach — it delivers all six key electrolytes (magnesium, calcium, potassium, chloride, sodium, and phosphorus) plus vitamin C and zinc, but with a notably lower sodium content than LMNT or SALTT. This makes it a gentler option for those who are sodium-sensitive or just starting their fasting journey and don’t need the full 1,000 mg hit. The 36-stickpack variety box gives you nine flavors, from Blue Raspberry to Pink Lemonade, all sweetened with organic stevia leaf extract.
The formulation is vegan, gluten-free, and keto-friendly with zero sugar and zero calories. Users on GLP-1 medications or dealing with fasting-related migraines have reported noticeable symptom relief without the harsh saltiness of higher-sodium mixes. The powder dissolves rapidly with a quick stir — no blender bottle required — and leaves no chalky residue at the bottom of the glass.
The tradeoff is clear: if your fasting window exceeds 24 hours, you may need to use two packets to reach the sodium levels that prevent dizziness. But for daily intermittent fasting (16:8 or 18:6), the single-packet approach works well and tastes clean enough to drink every day without flavor fatigue.
Why it’s great
- Full electrolyte spectrum (6 minerals) plus vitamin C and zinc
- Pleasant flavor profile with no artificial aftertaste
Good to know
- Lower sodium per serving requires double-packing for extended fasts
- Some users may prefer a less sweet taste profile
3. SALTT Electrolytes Powder Packets – Ultra Variety Pack
SALTT (by Keto Chow) brings a dense mineral profile — 968 mg sodium, 409 mg potassium, and 178 mg magnesium per serving — making it one of the most complete electrolyte blends for fasting. The 30-stickpack Ultra Variety pack includes flavors like Lemon Lime, Zesty Orange, and Grapefruit. Users on sweaty hikes and long fasts alike report that the higher potassium content (almost double LMNT’s) noticeably reduces muscle cramping during extended windows.
The ingredient list is remarkably clean: no sugars, no maltodextrin, no fillers, and no citric acid. The powder dissolves quickly with no clumping, even in cold water. Several reviewers noted that the saltier taste is more palatable than LMNT’s sweetness, though the unflavored packets included in the variety pack received mixed reactions — some find them undrinkable, while others appreciate the option.
The main practical drawback is the packaging: the individual packets require scissors to open cleanly, which is less convenient than tear-notch pouches. Also, the “Endless Summer” flavor (a light fruit punch) and Mondo Melon are divisive — some love them, others find them odd. Stick with the fruit-forward flavors for reliable results.
Why it’s great
- Highest potassium content (409 mg) for cramp prevention during long fasts
- No artificial sweeteners, fillers, or citric acid
Good to know
- Packets are tough to tear by hand — scissors required
- Unflavored and some “odd” flavors may be polarizing
4. Keto Chow SALTT Electrolytes – Fruit Variety Pack
The Fruit Variety edition of SALTT mirrors the Ultra Variety in mineral content (969 mg sodium, 409 mg potassium, 178 mg magnesium) but swaps out the savory and unflavored options for a full lineup of fruit flavors. This is the smarter pick if you plan to drink electrolytes daily and want variety that actually tastes good — flavors like Booyah Berry, Blue Slushies, and Lemon Lime have consistently high praise from the fasting community.
A reviewer with POTS (postural orthostatic tachycardia syndrome) noted that SALTT broke a weight loss stall that LMNT and Liquid IV couldn’t, attributing it to the higher potassium and magnesium without the aftertaste. The formulation uses non-table salt for a cleaner mineral taste, and the powder mixes transparently without leaving a gritty layer at the bottom of the bottle.
Like the Ultra pack, these packets require scissors, which is a small but real friction point when you’re mid-fast and fumbling in your bag. The “Cherry Chill” flavor has been compared to cough syrup by some users, so start with a single packet before committing to a subscription of that specific flavor.
Why it’s great
- 10 distinct fruit flavors reduce taste fatigue during daily use
- Higher potassium-to-sodium ratio than LMNT for balanced hydration
Good to know
- Packets require scissors — not portable-friendly for on-the-go use
- Cherry Chill flavor polarizing; sample before subscribing
5. REDMOND Re-Lyte Hydration – Variety Pack
REDMOND Re-Lyte stands apart because its sodium source is unrefined Redmond Real Salt — an ancient sea salt containing 60+ naturally occurring trace minerals beyond standard electrolytes. The 2:1 sodium-to-potassium ratio (around 400 mg sodium to 200 mg potassium per serving) is more conservative than the SALTT or LMNT profiles, making it a gentler option for those who want the trace mineral benefits without the full high-sodium punch.
The formula includes dual magnesium sources and coconut water powder for additional mineral depth, and it’s sweetened with stevia leaf extract. Users with POTS have reported that Re-Lyte is a “life saver” for morning orthostatic symptoms, and the flavors (like Lemon Lime and Watermelon) are consistently praised for not being overly salty or sweet. The powder mixes best when dissolved in a small amount of water first, then diluted to avoid clumping.
The catch: the lower sodium content means you’ll likely need two packets per serving for extended fasts beyond 24 hours, which cuts into the value proposition. Also, the coconut water powder, while natural, adds a subtle flavor note that doesn’t pair well with all the fruit varieties.
Why it’s great
- Unrefined salt source provides 60+ trace minerals for deeper nutrition
- Milder taste profile — less salty and less sweet than competitors
Good to know
- Lower sodium per packet may require double dosing for long fasts
- Powder can clump if added directly to full water; pre-dilute
FAQ
Can I use any electrolyte powder while fasting?
How much sodium do I actually need per day while fasting?
Will taking electrolytes break my fast for autophagy?
Why do I get muscle cramps during a fast even with electrolytes?
Final Thoughts: The Verdict
For most users, the electrolytes for fasting winner is the LMNT Zero Sugar Variety Pack because its 1,000 mg of sodium per serving exactly matches what your body loses during an extended fast, with zero sugar and a clean stevia-sweetened taste. If you want a lower-sodium option that still delivers good flavor and a full mineral spectrum, grab the Ultima Replenisher Variety Pack. And for the highest potassium content available in a packet — ideal for cramp-prone fasters — nothing beats the SALTT Ultra Variety Pack.