Hello Atul Sir,
Thank you for your question,
I would like to explain you the action of minioxidil first,
As minioxidil helps to preserve existing hair and to give strength to the hair or roots available , The minoxidil lotion when applied topically widens the blood vessels and opens the potassium channels this helps to get more blood supply and oxygen + growth factors to the hair follicles , most of the people see hair loss after application of minioxidil , as minioxidil may cause follicles in the telogen phase to shed off then the new anagen phase replaces it with strong hair.Minioxidil works to prolong the growth phase of hair follicle , it is the FDA approved medication used in both male and female pattren hair fall.
So minioxidil will help you the preserve existing hair
Hair fall or Hair loss in men is mostly due to Androgen hormone + genetic factors , rest all other are the contributing factors such as nutritional deficiency / stress / pollution / enviromental changes etc..
So mostly no one can change the genetic pattern or the hormonal pattern in human. So in hair loss or hair fall we can just postpond the process of baldness with the help of minioxidil and other mode of treatments, and no one can completely stop the process of baldness.
MINOXIDIL TOPICAL LOTION IS ADVICED FOR HAIR LOSS CONTROL
Minioxidil And Other line of treatment you can achieve good results and make your hair strong.
Other : Mesotherapy / PRP / Low level light therapy / Multivitamin support etc…
So you can definately use minioxidil all over you scalp + head it will not cause any adverse effect on the hair alerdy situated.