+ 2026: The GH Optimization Stack — Complete Research Guide

What Are and ?

and are two growth hormone secretagogues that work through complementary mechanisms and are almost always researched together as a stack. Understanding each one individually clarifies why the combination is so popular.

is a synthetic analogue of growth hormone-releasing hormone (GHRH). GHRH is the natural signal that tells the pituitary to produce growth hormone. mimics this signal, stimulating GH release from the pituitary gland. The DAC (Drug Affinity Complex) version has a much longer half-life (~6-8 days) vs the non-DAC version (~30 minutes). Most research protocols use the non-DAC version for more controlled, pulsatile GH release.

is a growth hormone releasing peptide (GHRP) — specifically a selective ghrelin receptor agonist. It stimulates GH release through a completely different pathway than , and crucially, it does so without significantly affecting cortisol or prolactin (a limitation of older GHRPs like GHRP-6 and GHRP-2).

How the Stack Works

• (GHRH analogue): Binds GHRH receptors on pituitary somatotroph cells → increases GH synthesis and release amplitude
• (GHRP): Binds ghrelin receptors on pituitary → increases GH release frequency and inhibits somatostatin (the "brake" on GH release)
• Combined effect: amplifies the pulse size while increases pulse frequency and removes inhibitory signals — producing larger, more frequent GH pulses while maintaining the natural pulsatile pattern

This matters because maintaining pulsatile GH release (rather than constant elevation) more closely mirrors natural physiology and is associated with better IGF-1 response and fewer side effects than continuous GH elevation.

Research Findings

• Body composition: GH secretagogue research consistently shows improvements in lean mass and reductions in fat mass, particularly visceral fat
• Recovery: Enhanced protein synthesis and reduced recovery time in exercise-related research
• Sleep quality: Growth hormone is primarily released during slow-wave sleep; GH secretagogues administered before sleep show improved sleep architecture in some research
• Bone density: Long-term GH optimization research shows positive effects on bone mineral density
• Skin quality: Consistent with GH's known effects — improved skin elasticity and thickness observed in GH-related research

Dosing Protocol

The most common research protocol for (no DAC) + :

• Timing: Administered together in the same injection — typically before bed (to amplify the natural GH pulse during sleep) and/or post-workout
• Frequency: Once or twice daily protocols are most common in research
• Administration: Subcutaneous injection
• 10mg blend vials: Pre-blended + vials (like those from UNYX) simplify the protocol significantly — one reconstitution, one injection

Reconstitute with bacteriostatic water. Store refrigerated. See reconstitution guide for details.

Without DAC — Alone vs Stacked

Some researchers choose to use without DAC alone. The tradeoff: lower cost, simpler protocol, but significantly less GH stimulation. The synergistic effect of the combined stack is well-documented enough that most research protocols now default to the combination.

WITH DAC is a different consideration — the week-long half-life means constant GHRH receptor stimulation, which can lead to receptor desensitization and blunting of the pulsatile GH release pattern. Most researchers prefer the no-DAC version for this reason.

Where to Buy +

UNYX Peptides carries both individual vials and a pre-blended + blend. The blend is the most convenient option for researchers running the standard stack protocol. US-manufactured at GMP Arizona facility.