To be honest I think it is probably just an old fashioned hair tonic, the type my dad would use.
Some of the videos on You Tube are dodgy, with all the tricks under the stars under pinning them ie light back ground v dark back ground, different lighting/angles, fibres etc. but there are quiet a few that seem 100% genuine with remarkable recoveries.
Unfortunately I don't speak Thai so I have no idea about the time lines involved or what they are claiming but as with all treatments nothing happens for 3 months anyway. The UK distributor has had a good recovery for a guy in his mid 60s so roll on 3 months.