That is an excellent question. By laser toning, I think you are referring to the popular Qswitched Nd-Yag 1064nm laser? The answer may surprise you, but the recommended interval described in most Western clinical studies is monthly.
However, as the Asian skin type is darker, there are some doctors who employ a “lower energy” treatment approach for better safety, and a narrower treatment interval. The shortest interval between Qswitched 1064nm toning I have found in published studies for Asian skin types is two weeks (Treatment of Melasma with the Photoacoustic Twin Pulse Mode of Low-Fluence 1064nm Q-Switched Nd:YAG Laser). This is in-line with my own practice, I never ask patients to come back sooner than 2 weeks.
Lasers are not a toy and should be treated with respect by using proper protocols designed by dermatologists and aesthetic physicians. I would avoid places who recommend lasers at an interval more frequent than 2 weeks. Some local famous business oriented clinic chains even recommend daily toning routines, which do more harm to the skin than provide benefit.
For your interest, there are also other forms of laser toning, including long pulse green toning (shown to improve melasma beyond standard 1064nm Qswitch) as well as long-pulse 1064nm toning (for wrinkles and skin rejuvenation). I use a mixture of all these in my practice to achieve better results.
Hope this helps!
