"Can peptides increase PSA?" Hmm...if you need to ask if something could be a side effect of the medication you're prescribing, you probably shouldn't be prescribing that medication. More concerningly, though, there doesn't seem to be any concern for that other thing that can cause a man's PSA to rise rapidly...you know, prostate cancer? The second most common cause of cancer-related deaths in men in the United States? What is NP Mindy going to ask next - "can peptides cause bony lesions?"