Stacking
Combining a GHRH analog like sermorelin with a growth hormone-releasing peptide (GHRP) that acts on the ghrelin receptor produces a synergistic effect that exceeds the GH output of either compound alone. This occurs because the two peptides act on different receptor pathways that converge on the somatotroph cell.
Sermorelin + Ipamorelin
The most widely prescribed combination. Sermorelin provides the GHRH signal while ipamorelin activates the ghrelin/GHS-R1a pathway, creating a dual stimulus on pituitary somatotrophs. Ipamorelin is preferred over older GHRPs because it does not significantly elevate cortisol, prolactin, or appetite. A common protocol uses sermorelin 200 to 300 mcg + ipamorelin 200 to 300 mcg, administered together subcutaneously at bedtime.
Sermorelin + GHRP-6
An older combination that produces robust GH release. Research has demonstrated that co-administration of GHRH with GHRP-2 (a closely related peptide) produced a synergistic 54-fold increase in pulsatile GH secretion compared to baseline in one study. GHRP-6 is effective but less selective than ipamorelin. It increases cortisol and prolactin to a greater degree and stimulates appetite through ghrelin receptor activation, which may be desirable or undesirable depending on the patient's goals.
Sermorelin + CJC-1295
Since both are GHRH analogs acting on the same receptor pathway, combining them does not produce the same synergistic effect as pairing with a GHRP. However, some protocols use sermorelin for its acute pulsatile effect alongside CJC-1295 (no DAC) to provide additional GHRH receptor occupancy with a slightly different pharmacokinetic profile. This combination is less common and less evidence-based than GHRH + GHRP stacks.