Everyone’s teeth are different. We all have different body chemistry, dental health, genetics, etc. Most people will experience a 2-4 shades whiter difference with a 20-minute treatment, and 5-8 shades difference with a double (two back-to-back 20-minute regimens) treatment session. The new multi-session regimen, which is five 20-minute treatments any way the client wants, doing no more than a double in any 24-hour period, over the next six months, may result in more than 8 shades whiter from start to finish. Overall, over 98% of White Guys clients are absolutely thrilled and ecstatic about their treatment results. The “WOW!” factor is huge.