I don't know if it's a prohormone, but it does contain hormone(s) that are found in our body. For example:
Adrenocorticotrophin is obtained from the anterior lobe of the pituitary gland. It contains hormones that increases the rate at which corticoid hormones are secreted by the adrenal gland. It is a protein consisting essentially of a single chain of amino acids. Approximate molecular weight 3,500.
-Homeopathic Online
To me, it does not look like a prohormone.