@seoulbeautyclub: What to mix and what not: 1. Vitamin C + Retinol ❌ 2. Vitamin C + Niacinamide ✅ 3. Retinol + BHA ❌ 4. Retinol + Niacinamide ✅ 5. Hyaluronic Acid + Everything ✅ Save this video and follow for more tips! ✨ #skincaretips #skincarehack #dosanddonts #kbeautytips