When using multiple Spectrals, such as the F7 and DNC-N for instance, the order of application is not important.
We recommend that you apply one, wait a few minutes for it to settle in and dry and then go ahead and apply the other spectral.
We might also suggest applying one topical treatment in the morning, and the other in the evening.
It does not matter which Spectral you apply first. Every person is different, and it can take a bit of trial and error to determine the right routine for you.