You could try Tu Si Zi (Chinese Dodder Seed) which increases the weight of the pituitary gland. I have used it for 20+ years because half of my pituitary is destroyed and it makes the world of difference to me. It benefits the Kidney Qi also which is universally beneficial.

It does increase a number of pituitary hormones such as testosterone and FSH. Do a search for it and see the effects. There is no too much conventional research but there are some indications such as increasing the pituitary weight in animals, rats I seem to remember.