Keto flu is usually a salt problem, not carb withdrawal.
Cut carbs and your insulin drops, which tells your kidneys to flush sodium and water — taking potassium and magnesium with it. That's the headache, the fatigue, the cramps. It's not your body detoxing from sugar; it's electrolyte depletion, and it usually clears within hours of replacing them. Here are the honest amounts, and the cheap way to hit them.
See the cheapest way to hit it →Why low-carb makes you lose salt.
On a normal-carb diet, insulin runs a little higher and signals the kidneys to hold onto sodium. Drop the carbs and insulin falls — the kidneys reverse course and start excreting sodium and the water bound to it. Most people shed 2,000–4,000 mg of extra sodium in the first week of ketosis, along with the potassium and magnesium that follow it out. That rapid loss is the keto flu: low energy, headache, lightheadedness on standing, and muscle cramps — the same electrolyte-gap symptoms you'd get from heavy sweating, just arrived at from the kidney side rather than the skin.
The amounts the research actually recommends.
These come from the low-carb clinical literature — notably Phinney and Volek's work — and they're higher than standard guidance precisely because the diet increases your losses:
| Per day on keto | Target |
|---|---|
| Sodium | 3,000–5,000 mg |
| Potassium | 3,000–4,000 mg |
| Magnesium (elemental) | 300–500 mg |
A lot of that can come from food — salt your meals to taste, a cup or two of broth, and several servings of non-starchy vegetables for potassium. The gap that's left is exactly what a fixed-dose electrolyte stick is sold to fill, at about $1.50 a serving. You can fill it for a few cents.
Hit it for pennies, not $1.50 a stick.
The popular keto electrolyte brands are a fixed blend of exactly these three minerals — the category was practically built on the keto market. There's nothing wrong with the formula; you're just paying a dollar-plus a serving for minerals that cost a few cents in bulk. The same sodium, potassium and magnesium from pink salt, potassium chloride and a magnesium supplement lands your daily target for a fraction of the price — and you can tune it to how you actually feel.
Every product, mg by mg
The keto brands and the raw minerals, elemental mg and real cost, side by side.
Make your own
Pink salt + potassium chloride + magnesium at your ratio — the cheap way to hit the target.
The stick vs your own
Why a fixed dose is a convenience you pay a premium for, and when it's worth it.
Sources: Virta Health, sodium, potassium & magnesium on a ketogenic diet; Phinney & Volek, The Art and Science of Low Carbohydrate Living (sodium 3–5 g, potassium 3–4 g, magnesium 300–500 mg/day; ~2–4 g sodium lost in the first week of carb restriction).
Fix the flu, keep the money.
Hit the same electrolyte target the sticks sell, for a few cents a day.
The cheap keto mix →