Some good discussions and personal anecdotes in this thread:
I'm currently taking 500mg metformin twice per day as part of an anti-aging protocol. One thing I noticed is that it does seem to reduce cravings, so it's actually easier to eat healthy because you just don't crave junk food as much.
This guy, who apparently had way too much coffee, disagrees:There’s a recent article in NYT that describes success taking Minoxidil internally at very low doses. By chance saw a tweet about it. Claims to be very safe with no side effects.