There are many different analogs of IGF available, instead of mentioning them all, I will simply mention the two most common and the most effective. Regular recombinant IGF is one of the two, it is also the more expensive and the least effective. Regular IGF only has a half-life of about 10-20 minutes in the human body and is quickly destroyed, it can be combined with certain binding proteins to extend the half-life, but it is not a very simple procedure and there is a more effective and less expensive version available.