Ok to use injectable Gerovital as retention enema?

I am currently taking multiple injections due to significant malabsorption issues and a non functioning small intestine etc. I take human placenta, gerovital hg3, glutathione, glutamine, minerals and b vitamins. I am wondering if anyone knows if any of these can be taken just as effectively as retention enemas? Especially the gerovital which is a 5cc injection and I am a petite woman that is beginning to feel like a pin cushion.

I know retention enemas can be powerful and are another form of injecting liquid substances into the body but I don't know if crossing the blood plasma via an enema is safe or if amounts for an im injection need to be adjusted.

Thanks for any help!