The restriction against manufactured drugs vs. naturally occurring substances only exists for game balance purposes. There are plenty of natural substances that take us so many thousands of times the resources to create in a lab where some synthesis of other compounds are simple but do not occur in nature... for a number of reasons; no evolved need, toxic (but not useful), etc. . And before someone argues that this proves their point about only natural products, we still don't understand how many natural products are actually created because we don't understand how the natural organisms put it all together. With the right kind of technology you could rearrange damn near any organic compound into a target compound. Now this could lead to some bizarre deficiencies in your body if the gland was aggressive enough, it needs to get its resources from somewhere it doesn't just show up miraculously. Of course BADs are an entirely different subject as even in 2072 they don't fully understand how they work, what with the magical component. Additionally I can't speak for combat drugs of the future but I can tell you that modern amphetamines would be fairly simple for these glands to create... IF it wasn't simply a matter of game balance.