How long is acceptable to lose money on PPC ads as a new seller and first product?

Hey everyone! Just curious how long you should be willing to lose money on PPC ad with your first product? I would love to here any encouraging stories about losing money at first and then finally profiting.

Also how long would you let an ad run for before trying to optimize it, considering that its already getting clicks and a few sales in the beginning but acos is high. I feel like i tried optimizing to quickly with out enough data.

Thanks!