If someone has non classical congenital adrenal hyperplasia, how long once on treatment until effects are visible?

Depends: This is very patient dependent. I would ask your doctor this specific question. Each patient can act differently to a treatment for their specific disease or illness.

It depends: If you are referring to non classic 21 hydroxylase deficiency in a woman, it will depend on the treatment. Both treatment with adrenal suppression with steroids and androgen blockade will result in decreased testosterone effect. Clinical effects generally take 3-6 month to see. It can take longer to have the full effect, particularly with hair. Blood pressure changes can happen faster.