Nobody can answer that question, i got it after a few hours after the application, at least the fatigue, the other sides maybe later, you have to check it or you might think you are tired of something, check tension, heart beats per minute, but consider also that i dermarolled not long before i applied the minoxidil, so the possibility of getting it into the bloodstream is way bigger than if you would just apply it without any dermaroll or something. But i don't have any experience about what it does to the beard because i never used it on the beard, i only have the general information about it, that is available online and from my own experience...
And the part with the permanent damage is mostly because i think that the hair that fell was supposed to fell anyways, the minoxidil only accentuated and made the process faster, and because i didn't use any DHT blocker, it never came back... It somehow messes with the hair cycles keeping the hair more in the growing faze, making all the hair shed at once, somehow synchronizing the cycles but nobody knows exactly, everybody responding differently to it, unfortunately you would have to try it to see how it works or if it works, for some i heard it does nothing, not to hair, no sides, no nothing...
And 1 month is gonna do nothing much, you must stay on it at least 3 months, that's if you don't see in those 3 months something bad happening, hair, sides, etc... You could shed and grow back after 10 times stronger, but as i said, it's just an illusion, once you stopped, it's gonna fall out. And if let's say you use it for 1 year and after 1 year you ditch it and more hair falls and you end up under the baseline, that means that the hair was supposed to fell anyways and it felt under the minoxidil treatment, it would have fallen anyways, maybe sooner, or maybe later, nobody knows exactly... It's a gamble to put it more simple, like it is with any of these drugs....