Every "best electrolytes for fasting" list you'll find online ranks products the same way: taste, price, brand reputation. Almost none of them actually pull the label and compare the numbers that matter for someone fasting specifically. So I did that here, including for Optimize. I'm not going to pretend our formula wins on every metric, because it doesn't. What I can tell you is exactly where each product is strong, where it's weak, and which one actually fits your situation.

What Actually Matters When You're Choosing One

Before the comparison, here's the criteria I used, and why each one matters if you're fasting rather than just generally hydrating. For the fundamentals behind why these minerals matter and how much you actually need, I've written a complete guide to electrolytes for fasting here.

Zero calories, zero sugar. This is table stakes. If it has calories or triggers a real insulin response, it isn't fasting-safe, no other questions needed.

Real doses of sodium, potassium, and magnesium, listed individually. I've written before about why sodium is the electrolyte that depletes fastest during a fast, driven by the drop in insulin that happens a few hours into your window. Potassium and magnesium matter too, just on a slower timeline. A product that buries these behind a "mineral blend" instead of listing actual milligrams isn't giving you enough information to make a real decision.

What sweetener it uses, if any. Most electrolyte brands use stevia. I've written a full breakdown on stevia and fasting here, but the short version is that the research on whether it affects insulin is mixed, and even when it doesn't, it can keep sugar cravings alive during a window where the goal is often to let them fade. That's a personal call, not a disqualifier, but it's important to keep in mind.

No "natural flavors." That phrase can legally cover dozens of undisclosed compounds, and it's frequently carried in maltodextrin, a processed starch used to bind and stabilize the flavor compound that never shows up as its own line on the label. I've written about what's actually hiding behind that phrase here. Products that use real, named ingredients for flavor let you know exactly what's going into your body, carrier ingredients included.

What the sodium source actually is. "Sodium" on a label usually means standard sodium chloride, the same refined salt in a saltshaker. That's fine, but it's not the same thing as a sea salt or mineral salt, which carries trace minerals along with the sodium. Worth checking which one you're actually getting.

Price per serving. Clean ingredients cost more. That's real, and it should factor into which one makes sense for your budget, not just your ideal formula.

The Comparison

LMNT
Sodium: 1,000mg. Potassium: 200mg. Magnesium: 60mg. Sweetener: Stevia leaf extract. Natural flavors: Yes. Price: About $1.50 per serving.

LMNT leads the field on sodium by a wide margin, and if heavy sweating, hard training, or long fasted windows are your main concern, that matters. Magnesium is also solid here, better than most of the field. Worth knowing: the sodium comes from standard sodium chloride, not a sea salt or mineral salt, so you're getting sodium and chloride and nothing beyond that. There's also stevia and natural flavors in the ingredient list, and nothing in the formula beyond the three electrolytes. No functional ingredients, no blood sugar support, just minerals. Each flavored stick contains a small amount of calories as well, and there is a small amount of maltodextrin hidden in their natural flavors. For someone whose only question is "which one replaces the most sodium," LMNT is a legitimately strong answer. For quality and label transparency, it falls short.

Redmond Re-Lyte
Sodium: 810mg. Potassium: 400mg. Magnesium: 50mg. Sweetener: Stevia leaf extract. Natural flavors: Yes. Price: Around $1.00–$1.20 per serving.

Re-Lyte has the strongest potassium dose of the group by a wide margin, double LMNT's, and a very reasonable sodium number alongside it. Its sodium source is Redmond's Real Salt, an unrefined sea salt that carries 60-plus trace minerals along with it, a real point of difference from the plain sodium chloride in LMNT and Ultima. The tradeoff is the same as LMNT, though: stevia and natural flavors both show up on the label, with the potential of hidden maltodextrin inside. If potassium is the piece you've been undersupplying, this is the strongest option here, but again, Re-Lyte falls short with quality and label transparency.

Ultima Replenisher
Sodium: 55mg. Potassium: 250mg. Magnesium: 100mg. Sweetener: Stevia leaf extract. Natural flavors: Yes. Price: About $0.47 per serving.

Ultima is the cheapest option by a significant margin and carries the highest magnesium dose of the four. But I have to be direct here: 55 milligrams of sodium is not a meaningful amount for someone fasting. Given that sodium is the electrolyte your body loses fastest and most urgently during a fasted window, Ultima's formula reads like it was built for general daily hydration, not for the specific demands of fasting. The sodium is standard sodium chloride, same as LMNT, so no trace mineral upside there either. It's a fine everyday mineral supplement. I wouldn't rely on it to get you through a long fasted window without adding sodium from somewhere else. It's also worth noting citric acid is a larger ingredient in the product, and there may be hidden maltodextrin inside the natural flavors as well.

Optimize
Sodium: 290mg. Potassium: 145mg. Magnesium: 30mg. Sweetener: None. Natural flavors: None (flavored with real ginger, lemon peel, and vanilla bean). Price: About $1.50 per serving.

I'll be straight about the numbers first: Optimize doesn't win this comparison of minerals on paper. LMNT and Re-Lyte both carry more sodium, Re-Lyte and Ultima both carry more potassium, and Ultima carries more magnesium. If the only thing you're optimizing for is the highest mineral dose per scoop, one of the other three gets you there for the same money or less. The sodium comes from real sea salt rather than refined salt, similar in spirit to what Re-Lyte does, though we don't market a specific trace mineral count the way they do.

What changes the picture is how often you can actually take it, and what's actually inside. Optimize is light enough to use more than once a day without creeping toward a daily ceiling most people never think about. General guidance caps sodium around 2,300 milligrams a day, and two servings of LMNT alone puts you at 2,000 of that before you've eaten anything. NIH's upper limit for supplemental magnesium is 350 milligrams a day, and two scoops of Ultima gets you to 200 before food. A second or third serving of Optimize, morning, pre-workout, before you break your fast, doesn't put you anywhere near those numbers. The higher-dose products on this list weren't really built to be taken that often, and that's the part nobody mentions when they lead with "more sodium is better."

That repeat use matters because the rest of the formula isn't just electrolytes. L-theanine (150mg) is the amino acid behind the calm, clear-headed feeling people get from green tea, without the caffeine, and fasting fog is a real problem for a lot of people that none of the other three products here even attempt to address. Ceylon cinnamon has research behind it for blood sugar support, and steadier blood sugar is directly tied to fewer of the headaches and crashes that push people to break a fast early. Ginger and lemon support digestion, which matters most right before you break a fast, when your gut has gone quiet and needs to ease back in. LMNT, Re-Lyte, and Ultima are all built purely for hydration. None of them are thinking about that part of the window at all.

If you need maximum sodium in one serving because you're sweating hard or training fasted, Optimize isn't the strongest pick, and I'd rather say that plainly than talk around it. But most people aren't using an electrolyte supplement for one serving on their hardest training day. They're using it multiple times through an ordinary fasting day, and that's what Optimize is actually built for: electrolytes plus mental clarity, blood sugar support, and digestion, without running into the ceiling the higher-dose formulas hit if you use them the same way.

How to Actually Decide

If you train hard fasted or sweat heavily and sodium replacement is your main concern, my suggestion is to use Optimize with a pinch of sea salt. You'll get the increase in sodium without the added fillers and higher price tag. If potassium is the piece you've been undersupplying, Re-Lyte's 400 milligrams leads the field. If you want the lowest price and don't mind a lighter sodium dose, Ultima works as a general mineral supplement, though I'd pair it with added salt during a real fasted window. If you want to take your electrolyte supplement more than once a day, whether that's morning, pre-workout, and pre-refeed, or you want mental clarity and blood sugar and digestive support built into the same scoop instead of hydration alone, and you want true label transparency with zero natural flavors or hidden maltodextrin, Optimize is the formula built for that.

These products are built around different priorities. The mistake is picking one because of a brand name or a flavor and never checking whether the label matches what you need.

The Bottom Line

Pull the label before you buy. Look at sodium, potassium, and magnesium as actual milligram numbers, not just names on an ingredient list. Decide whether a sweetener matters to you, and if it does, check for it specifically because most of this category uses stevia. Then match the formula to what you're actually doing: hard training, a long fast, daily maintenance, or a cleaner label overall.

If that's a formula with real doses, zero sweeteners, and functional ingredients that support the fast itself, Optimize was built for exactly that. If your priority is maximum sodium or potassium above everything else, I'd rather tell you that honestly and point you to the option that actually delivers it than sell you something that doesn't fit what you need.

Fuel your fast, feel your best.

Sources and Further Reading

Effects of Sodium and Potassium, CDC.
Potassium: Fact Sheet for Health Professionals, NIH Office of Dietary Supplements.
Electrolytes for Intermittent Fasting, Fasted State Supplements.
The Truth About Stevia and Fasting, Fasted State Supplements.
What Are Natural Flavors Really Made Of?, Fasted State Supplements.