My nurse told me to start them 5 days post op – my packet had the same instructions as yours but I did 4 times a day on the 5 days pre-op, then every 2 hours 1st day post op, then back to 4 times a day until I’d finished the pack which was about 6 days post-op. I read somewhere (sorry can’t remember where) that you’re not recommended to take arnica continuously for more than 10 days in a row so this seemed sensible. My swelling went down really quick & I had no bruising whatsoever even with my uplift so I deffo recommend it!!x