What peptides should not be stacked together?

Avoid stacking two GHRH peptides together (such as CJC-1295 and Sermorelin) or two GHRP peptides together (such as Ipamorelin and GHRP-2), as they target the same receptors and can cause excessive hormone stimulation. Combining multiple growth hormone-related peptides may lead to water retention, insulin resistance, or joint pain. A general rule is to limit stacks to two or three peptides with complementary rather than overlapping mechanisms of action.