I'm satisfied with the effectiveness of Plantar 39 shampoo+conditioner. After the first wash, my patch of grey hair on my crown turned noticeably to light reddish brown. (Unfortunately, I didn't take the 'before' photo.) After 10 washes, there is no obvious grey hair (unless one scrutinises it up close). In addition, there was less hair loss (roughly 15-20% less). I am glad to have discover Plantar 39. Thank you, Dr Wolff.