Check with your doctor, it may also be stress induced or other illnesses.
but even if it is MPB, so what, let it go, shave it off. don't try to cover it up with medication that don't work or implants or
I started to lose my hair around the crown of my head when I was about 20-21. I just shaved all my hair short with clippers and forgot about it. Over the years I've "lost" more hair so that now I have the classic hair at the sides and back but nothing on top. Having it shaved close means it's no issue. If i'd spent time and money to "slow" the progress it would just end up drawing more attention to it. People see someone trying to hide the fact they're losing their hair and THAT shows other people that the person in question has esteem issues. It isn't a cool look even if you end up with some more hair on your head.
Plus I also get the added benefit of not having to worry about styling my hair or it looking tragic in 20 years when someone finds an old photo. The "Picard" look is timeless
Oh and in the last 8 or so years I've spent about $50 on haircuts (the price of 2 sets of hair clippers after the first one died).