I don't mean to be rude, but I don't think there's a single thing 'on' base in your post and I feel it's more due to the fact you read what you want to see/made up your mind you want to see, instead of what I'm writing.
I am talking about modification of inactive part of a known molecule, which in case of steroids is the ester and thus exchanging that part of the molecule is a process called transesterification.
I used such an analogy to provide an easy way to imagine it. I mean, over here, at Meso RX one would expect people to know both that testosterone is testosterone, whether it's acetate or decanoate and that esters influence only half-life and pharmacokinetics, not the receptors it binds to etc. etc. Different molecule, same effect, same receptors.
At least so was my assumption, especially when someone starts inquiring with me about concepts that are pretty much quantum physics compared to that, such as structural elucidation of novel compounds.
So no, it really is not 'homebrew,' ie. dissolving a substance and I really don't understand. I really don't think that when you brew trenbolone acetate you end up with trenbolone phenypropionate here and there. Do you have such experience?
Now I have literally no idea what you mean by DPP-4, but given lack of understanding of basic concepts that I believe had explained properly I am not inclined to investigate and have my professionalism insulted further on basis of ignorance.
Someone made a novel molecule with hope of getting around the patent law and thanks to our equipment, experience, knowledge and skill we were able to test it and here I am being accused of taking parts in marketing plays or jokes.