Used in the treatment of adrenal insufficiency and various inflammatory and autoimmune conditions such as multiple sclerosis, rheumatoid arthritis, and lupus. Helps diagnose congenital adrenal hyperplasia and assess adrenal gland function through stimulation tests. Employed in some cases of infantile spasms, a type of seizure disorder in children. Acts by stimulating the adrenal cortex to produce cortisol and other steroid hormones, making it valuable in managing conditions where natural ACTH production is impaired.