My original teeth weren't severely yellowed to begin with. During the consultation, they recommended about 2 sessions total, mentioning there's no need to undergo the procedure excessively many times, and currently I've only completed the first session. I wondered if one session would make a big difference, but overall, the yellowish tone has been clarified by about one shade. I'm pleased with the result because it's not an artificially white color, but rather my natural teeth appearing a bit cleaner. I'm looking forward to seeing how much brighter they'll become after the second session