Keto Side Effects & How to Prevent Them
Everything you need to know about keto flu and side effects - plus how to prevent them and feel great during your transition.
⚡ Good News: Most side effects are preventable with proper electrolyte management! Keto flu is optional, not inevitable.
What is Keto Flu?
Keto flu = temporary symptoms during the first 3-7 days as your body transitions from burning carbs to burning fat.
Common Symptoms:
- Headaches (most common)
- Fatigue and brain fog
- Irritability and mood swings
- Muscle cramps and weakness
- Dizziness when standing
- Sugar cravings
- Difficulty sleeping
Why It Happens
The Real Cause: Electrolyte Depletion
When you cut carbs, insulin drops. Low insulin = kidneys flush out sodium and water. Sodium loss causes other electrolytes (potassium, magnesium) to drop too.
You lose 3-5 lbs of water weight in the first week - this is why you feel dehydrated and depleted!
How to Prevent Keto Flu (The Fix!)
Electrolyte Targets (Daily):
Sodium: 5,000-7,000mg (2-3 teaspoons salt). Add salt to everything!
Potassium: 3,000-4,000mg (avocados, spinach, mushrooms, supplements)
Magnesium: 300-400mg (supplement with magnesium glycinate before bed)
Easy Electrolyte Drink Recipe:
1 cup water + 1/4 tsp salt + 1/4 tsp potassium chloride (NoSalt) + squeeze of lemon + stevia
Drink 2-3x daily in first week. Symptoms gone within hours!
Other Common Side Effects
Constipation
Cause: Less fiber, dehydration, magnesium deficiency
Fix: Drink more water, eat leafy greens, take magnesium supplement, add MCT oil or psyllium husk
Keto Breath (Fruity/Acetone Smell)
Cause: Acetone (a ketone) expelled through breath
Fix: Temporary! Goes away in 1-2 weeks. Chew sugar-free gum, drink more water
Leg Cramps
Cause: Low sodium, potassium, or magnesium
Fix: Electrolyte drink before bed, magnesium supplement, pickle juice
Timeline: What to Expect
Days 1-3: Carb withdrawal. Cravings, mild fatigue. Start electrolytes immediately.
Days 4-7: Worst of keto flu (if you skip electrolytes). Energy starts returning by day 7.
Weeks 2-4: Fat adaptation begins. Energy improves daily. Mental clarity returns.
Weeks 4-8: Fully fat-adapted. Stable energy, no cravings, physical performance restored.
When to See a Doctor
See a doctor if:
- Symptoms last more than 2 weeks despite electrolyte supplementation
- Severe vomiting or diarrhea
- Heart palpitations or chest pain
- Extreme weakness or difficulty functioning