This serum contains a retinol derivative to improve skin texture and give a youthful impression. TUNEMAKERS TUNEMAKERS Retinol Derivative 10ml New, unused, film removed but cap unopened, 2 bottles. Used once (about 2 drops), remaining amount almost 100%. A total of 3 bottles. No price reduction (will not respond). Individual sales: New bottle: ¥1600 Used once: ¥1200 Purchased in 2025/7. Please refrain from purchasing if you are sensitive to storage by an amateur. Shipping will be via Yu-Packet Post or Nekopos, anonymous delivery. No price reduction (will not respond). Instant purchase OK.