This depends on a few factors; average beard color duration is about 10-14 days.
Factors that determine color longevity:
1. Whisker quality (coarse or soft) and overall health (protein content in whiskers).
2. How well you clean the whiskers prior to application.
3. How long you leave the product on your whiskers (min 60 min first application).
4. Rate that your facial hair grows (super fast growth may require weekly touch-ups).
5. Frequency of face washing & products used (less washing and mild detergents increase duration).
The Best Practice: Make it a routine. A weekly application. 60 min for initial; then 30 min for touchups.