The link of Cosmic Serum was shared to you in your original post, in each serum article the use of each serum and possible combinations are mentioned.
Please go through the links, i am again reposting it here in this post.
Also check this link on Frequently asked questions.
We are happy to help you with your questions, but please do read all the links posted to you on your original post and in this post.
Serums or energies related to same aspects can be combined. Key PEN Serum is for kidney and pancreas and Heart Serum is for heart related problems. So advised to take separately.