Skinbio advises to use Hair Signals before going to bed at night.

Some studies have proved that physical exercise raises the DHT levels in men, so for people who exercise doesn't it make more sense to apply the solution during the day when the levels of the baldness causing hormone are higher?

You can apply them any time of the day. But since they are blue, many people apply them at night and wash out the copper peptides in the morning.

Thanks