General rule: 3 to 5 times per week for 15 to 20 minutes. By concern: Acne uses 3 to 4 times per week. Anti-aging uses 4 to 5 times per week. Sensitive skin uses 2 to 3 times per week. Maintenance uses 3 times per week. Can you use it daily? Yes but not always necessary. Results timeline: 7 to 10 days, 2 to 3 weeks, 4 to 6 weeks, 8 to 12 weeks. Signs of overuse: redness, dryness, sensitivity. Best routine: cleanse then LED then serums and moisturizers.