Fasting Hydration Guide
Best Electrolytes for Fasting (2026): Zero Sugar Picks That Actually Make Sense
The best electrolytes for fasting depend on what kind of fast you are doing and how strict you want to be. For most people, the best pick is a zero-sugar electrolyte with enough sodium to actually help you feel better while fasting.
Quick answer: LMNT is the best electrolyte for fasting if you want high sodium and a simple zero-sugar formula. Ultima is best if you want a lighter zero-calorie option. Buoy is best if you want unflavored drops you can add to water without turning it into a sweet drink.
Best Overall for Fasting
LMNT is the strongest option if fasting leaves you feeling depleted, headachy, or low-energy.
Best Zero-Calorie Daily Option
Ultima is easier if you want a gentler fasting electrolyte with no sugar, calories, or carbs.
Best Unflavored Option
Buoy works well if you want clean hydration drops you can add to plain water.
Best for Intermittent Fasting
LMNT usually makes the most sense if your main goal is staying sharp and avoiding low-sodium symptoms.
Best Electrolytes for Fasting: Side-by-Side Comparison
| Product |
Calories |
Sugar |
Sodium |
Best for |
| LMNT |
0 |
0g |
1000mg |
Longer fasts, keto, high sodium support |
| Ultima |
0 |
0g |
55mg |
Lighter daily fasting support |
| Buoy Hydration Drops |
0 |
0g |
Unflavored drops |
People who want a clean, flexible add-in |
What Actually Matters in an Electrolyte for Fasting?
For fasting, the biggest things that matter are usually zero sugar, no calories or very minimal metabolic impact, and enough sodium to help with headaches, fatigue, or that drained feeling people often get when they go too long with just plain water.
That is why products like LMNT, Ultima, and Buoy stand out more than sweeter hydration mixes. LMNT is built around a very high sodium formula with zero sugar. Ultima keeps things zero sugar, zero calories, and zero carbs, but with much lower sodium. Buoy is also zero sugar and zero calories, but in an unflavored liquid-drop format. :contentReference[oaicite:2]{index=2}
Best Overall: LMNT
LMNT is the best electrolyte for fasting if you want the most practical support for low-sodium symptoms. Each serving contains 1000 mg sodium, 200 mg potassium, and 60 mg magnesium, and it is zero sugar. That makes it the strongest fit for people doing intermittent fasting, keto-style fasting, longer fasts, or heavy sweating while fasted. :contentReference[oaicite:3]{index=3}
The biggest downside is that LMNT can feel like too much if you are just doing a short fast and want something lighter.
Best Lighter Option: Ultima
Ultima is the best choice if you want a fasting-friendly electrolyte that stays very light. A typical serving lists 0 calories, 0 sugar, 0 carbs, 55 mg sodium, 250 mg potassium, and 100 mg magnesium. That makes it a much easier daily option if you want zero sugar hydration but do not need a huge sodium hit. :contentReference[oaicite:4]{index=4}
The tradeoff is simple: Ultima is great for lighter hydration, but it is not usually the product people reach for when fasting symptoms clearly point to needing more sodium.
Best Unflavored Option: Buoy
Buoy is the best fasting electrolyte if you hate sweet powders and want something more invisible. Its Hydration Drops are unflavored and list 0 calories, 0 carbohydrates, and 0 sugar, which makes them appealing for people who want to keep fasting hydration simple. :contentReference[oaicite:5]{index=5}
Buoy makes the most sense if your goal is clean hydration support and flexibility. It makes a little less sense if you specifically want the high-sodium approach that many fasters prefer.
Simple breakdown: If fasting makes you feel weak or headachy, start with LMNT. If you just want a zero-sugar electrolyte for lighter daily use, go with Ultima. If you want something unflavored and easy to add to water, choose Buoy.
Do Electrolytes Break a Fast?
In practice, most people looking for fasting electrolytes are trying to avoid products with sugar and calories. That is why zero-sugar options like LMNT and zero-calorie options like Ultima and Buoy are the cleanest fit for this use case. :contentReference[oaicite:6]{index=6}
If your version of fasting is very strict, you will probably want to stick to the simplest formulas possible. If your goal is mainly appetite control, hydration, and making fasting sustainable, these products are much more practical than traditional sugary sports drinks.
Which Electrolyte Is Best for Intermittent Fasting?
For most people, LMNT is the best electrolyte for intermittent fasting because it brings the one thing many fasters actually need most: sodium. Ultima is the better fit if you want something much lighter and lower in sodium. Buoy is best if you want clean hydration without strong flavor.
My Picks
Best Overall for Fasting
LMNT is the strongest overall pick for fasting support, especially if you are going low-carb, doing longer fasts, or sweating a lot.
Shop LMNT
Best Light Zero-Sugar Option
Ultima is the better fit if you want fasting-friendly hydration without a big sodium load.
Shop Ultima
Best Unflavored Drops
Buoy is ideal if you want an unflavored option you can add to water without making it taste sweet.
Shop Buoy
Final Verdict
The best electrolyte for fasting is usually LMNT because it combines zero sugar with a much stronger sodium profile than lighter hydration products. LMNT’s published formula is 1000 mg sodium, 200 mg potassium, and 60 mg magnesium per serving. :contentReference[oaicite:7]{index=7}
If you want a fasting-friendly option that feels lighter, Ultima is the best zero-calorie daily pick. If you want something unflavored and flexible, Buoy is the cleanest-feeling option. :contentReference[oaicite:8]{index=8}
Frequently Asked Questions
What are the best electrolytes for fasting?
The best electrolytes for fasting are usually zero-sugar options with enough sodium to actually help. LMNT is the strongest overall pick, Ultima is a lighter zero-calorie option, and Buoy is a clean unflavored drop option.
Do electrolytes break a fast?
Most people doing fasting choose electrolytes with zero sugar and no calories or very minimal metabolic impact. That is why products like LMNT, Ultima, and Buoy are the most practical options for this use case.
What is the best electrolyte for intermittent fasting?
LMNT is usually the best electrolyte for intermittent fasting because it has a very high sodium content and zero sugar, which makes it more useful when fasting symptoms are tied to low sodium.
Is LMNT good for fasting?
Yes. LMNT is one of the strongest fasting electrolyte options because it contains 1000 mg sodium, 200 mg potassium, 60 mg magnesium, and zero sugar.
What is the best zero-sugar electrolyte for fasting?
Ultima is one of the best zero-sugar electrolyte options for fasting if you want something lighter, while LMNT is usually better if you also want much more sodium support.
