What do you know about Minoxidil 10% and 15% that is sold in the US?

Minoxidil is not available in 10% or 15% in the U.S. unless a doctor specifically prescribes them.  More (higher concentration) does not mean it works any better.

It is possible (and I do sometimes prescribed) to obtain higher doses of minoxidil for topical use.  This would be available by prescription only and sent to a compounding pharmacy which will make the solution exactly as the doctor prescribes (this includes the type of cream, solution, etc.).  Because minoxidil can be absorbed through the skin, sometimes increased side effects that would not be seen with the lower doses do happen but they are still very rare.  Consideration to using a higher dose means first failing treatment at a lower dose and also failing other treatments.  

It's pretty hard to find 10% and 15% minoxidil any more.The FDA has said NO! to companies making these products and forced them to remove these products from their shelves.The ONLY FDA approved concentrations are 2 and 5 %.Side effects are much increased at higher concentrations including dizziness, headaches, heart palpitations and others too.