What is the youngest age and dose that you would consider for oral minoxidil?  

I would consider prescribing oral minoxidil for children as young as 2 years old, but only if the condition is severe and does not respond to topical therapy.

I've prescribed it to men in their early 20's, starting at 2.5 mg daily and peaking bid, and I have had impressive results!

I utilize oral minoxidil in children, particularly in association with JAK inhibitors. Feel is very safe as documented by my recent review on this topic.Williams et al., PMID 38861138