What combines, what's redundant
Most marketed combos have zero human combination data.
A "stack" is usually the same mechanism sold several times over. Below: which combinations pair two real mechanisms, and which are the same bet padded with extra names. The count next to each makes it checkable.
Common combinations
SYNERGY · works together
CJC-1295 + Ipamorelin2 compounds · 2 mechanisms
Different receptors (a GHRH-analog + a ghrelin agonist) → additive GH release. The one genuinely complementary GH pairing; mechanism is sound, though human-outcome data is thin.
Cagrilintide + Semaglutide (CagriSema)2 compounds · 2 mechanisms
Amylin + GLP-1, two different appetite pathways. The ONLY combination here with real Phase-3 human trial data.
REDUNDANT · one mechanism, padded with extra names
Semaglutide + Tirzepatide (any two GLP-1s)2 compounds · 1 mechanism
Same incretin axis; dose-escalation wearing two names, with compounding GI / dehydration risk. Not diversification; your 401k in five S&P funds.
Retatrutide + any GLP-1 or GIP2 compounds · 1 mechanism
Retatrutide already triple-agonizes GLP-1 / GIP / glucagon. Adding another incretin is pure overlap.
Two GHRH-analogs (CJC + Sermorelin / Tesamorelin)2 compounds · 1 mechanism
Same GHRH receptor; a second one adds cost and risk, not mechanism.
MK-677 + Ipamorelin / GHRP2 compounds · 1 mechanism
MK-677 is an oral ghrelin-receptor agonist; stacking it with injectable ghrelin agonists hits the same receptor twice.
Melanotan II + PT-1412 compounds · 1 mechanism
Both melanocortin-receptor agonists; overlapping mechanism.
UNTESTED · no human combination data
BPC-157 + TB-5002 compounds · 2 mechanisms
The marketed 'recovery stack'; distinct repair mechanisms, but ZERO human combination trial, and both are Tier-D on human evidence individually. Anecdote, not data.
GLP-1 + BPC-157 (for GI side effects)2 compounds · 2 mechanisms
Different mechanisms (incretin + tissue-repair), but no human evidence that BPC-157 eases GLP-1 side effects, and BPC is Tier-D. A fix with no data behind it.
Epitalon + NAD+ + MOTS-c (longevity stack)3 compounds · 3 mechanisms
Three different mechanisms, but none is proven to extend healthspan in humans and there's no combination data. Three unproven bets, not a synergy.
GH secretagogue + a healing peptide2 compounds · 2 mechanisms
Distinct mechanisms (GH axis + tissue repair); plausible non-overlap, but no human combination evidence.
GLOW / KLOW / Wolverine blends3 compounds · 3 mechanisms
Pre-mixed multi-peptide products (GHK-Cu + BPC-157 + TB-500) sold as synergy; all Tier-D individually, zero combination evidence, and you lose per-compound dose control. Marketing, not a real combination.
CAUTION · works against itself
MK-677 + a GLP-1 (sema / tirz)2 compounds · 2 mechanisms
Works against itself: MK-677 raises appetite, blood glucose, and fluid retention, partly opposing a GLP-1's metabolic goal, with additive side effects. No combination data.
By mechanism
Within a single mechanism, a second compound is redundant; same receptor, no added mechanism. Across mechanisms, overlap is the exception, not the rule.
GLP-1 / incretin / metabolic 25
A ExenatideA SemaglutideA TirzepatideB CagriSemaB CagrilintideB DanuglipronB EfpeglenatideB MazdutideB OrforglipronB RetatrutideB SurvodutideB TesofensineB VK2735C AmycretinC EcnoglutideC EfinopegdutideC EfocipegtrutideC EloralintideC GlepaglutideC PemvidutideC PetrelintideD BRP-1SD BRP-2TD BRP-3RD GHRP-6
GH secretagogue / IGF axis 13 GHRH-analog + ghrelin agonist = the one real GH synergy
A Tesamorelin · GHRH-analogB GHRP-2 · ghrelin/GHS agonistB MK-677 · ghrelin/GHS agonistB Relamorelin · ghrelin/GHS agonistB Sermorelin · GHRH-analogC CJC-1295 · GHRH-analogC Hexarelin · ghrelin/GHS agonistD GHRP-1 · ghrelin/GHS agonistD IGF-1 DES · IGF / growth factorD IGF-1 LR3 · IGF / growth factorD Ipamorelin · GHRH-analogD PEG-MGF · IGF / growth factorF AOD-9604 · other-GH