Stack

A stack is a research protocol that runs two or more compounds simultaneously to produce a combined effect. The canonical example in peptide research is GHRH + GHRP — for instance, CJC-1295 (no DAC) + ipamorelin — where the two compounds act on different receptors (GHRH-R and GHS-R) and produce a larger GH pulse together than either alone.

Stack design is mostly about mechanistic complementarity: pick compounds that target different but synergistic pathways, and avoid stacking compounds with overlapping side-effect profiles unnecessarily. Recovery + Performance is a common archetype; Metabolic + Performance for body recomposition is another. Within-category stacks (two GLP-1s, two GH-secretagogues) are studied less often because the marginal benefit is smaller and side-effect overlap is higher.

Timing is the second axis of stack design: in many cases the best practice is to dose stacked compounds on different schedules so their peak windows do not unnecessarily compete for the same systemic resources or injection sites.