I am a female with shoulder length hair, yes a lot does get into my hair so I use 2-2.5 mls and apply it drop by drop and rub it in for a few seconds to make sure it doesn't go down my hair strands, and I've been having pretty nice results.
I think if my hair was as short as men's hair it would've been hella easier to apply, but yea it's possible to get results whatever your hair length is. However because of the miniaturization thing, some hairs don't really grow long before falling out, so you'll be alright to a certain length then you'll find your hair ends being see-through and stringy, that's if you are ever interested in really growing out your hair to a long length not just a few inches