Supplements during a fast sit in a gray zone. Some products are effectively calorie-free; others contain protein, sugar, or fillers that end the fasted state. This archive organizes common categories so you can decide what fits your schedule—without product pitches or affiliate links.
Electrolytes
Longer fasts and low-carb eating increase sodium and potassium loss through urine. Unsweetened electrolyte mixes with zero calories are widely used during fasting. Avoid gels, sports drinks, and powders with maltodextrin or sugar—they break the fast and spike blood sugar.
What to look for: sodium, potassium, magnesium; no added sugar; transparent labeling.
Related guide: Best Electrolyte Products for Fasting
Deep dive: Electrolytes During Fasting · Check specific items: Am I Breaking My Fast?
Coffee
Black coffee is standard during most IF schedules. Calories arrive with milk, cream, butter, or sweeteners. Caffeine affects people differently—some tolerate it fasted; others get jittery or acid reflux.
Related guide: Best Coffee Options for Intermittent Fasting
Related: Can You Drink Coffee While Fasting? · Fasting-Safe Drinks Explained
Tea
Unsweetened tea—green, black, herbal—is a fasting-friendly alternative to coffee. Pre-bottled teas often contain sugar; brew your own or read labels carefully. Matcha whisked with water only is similar to plain tea; café matcha lattes are not.
Related guide: Best Tea Options While Fasting
Multivitamins
Standard multivitamins contain negligible calories and are usually fine during a fast, though fat-soluble vitamins (A, D, E, K) absorb better with food. Gummy vitamins contain sugar and calories—they break a strict fast. Take timing-sensitive supplements in your eating window when possible.
Hydration products
Plain water first. Enhancement powders, flavor drops, and “water enhancers” vary—some are zero-calorie; others are not. BCAA-infused water, protein water, and coconut water all break a standard fast.
Related guide: Best Water Bottles for Fasting
Calculator: Water Intake Calculator · Guide: How Much Water Should You Drink Daily?
Quick reference
- Am I Breaking My Fast? — searchable drink & supplement directory
- What Breaks a Fast?
- What Can You Drink While Fasting?
- 16:8 Intermittent Fasting Guide
- Start Here
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