Most peptide stacks aren't designed — they're accumulated. Someone starts with BPC-157, adds TB-500 because a podcast mentioned them together, adds ipamorelin because 'GH is good', and six months later is running four compounds with no clear picture of what each is contributing. This guide walks through the opposite approach: designing a stack backwards from a specific goal, mapping mechanisms so nothing overlaps, choosing biomarkers you'll actually track, and — critically — writing down the stopping rule before you start. Every step references specific compounds from the library.
Step 1 — Define One Primary Goal (Not Three)
The single most common stack-design failure is trying to optimise for three things at once. Pick one primary outcome, allow one secondary, and rule the rest out for this cycle.
Rule: One primary goal (must be measurable). One secondary goal (bonus if you get it). Everything else is out of scope for this cycle.
Concrete goal examples that work:
- Achilles tendinopathy: reduce pain and improve loading capacity over 12 weeks
- Body composition: lose 6-8 kg over 20 weeks with lean-mass preservation
- Sleep architecture: increase deep sleep from ~15% to ~20% of total sleep time over 8 weeks
- Recovery from surgery: accelerate return to baseline function post-op
Goals that don't work as stack drivers:
- 'General optimisation' or 'longevity' — too vague to design against
- 'Feel better' — no measurable endpoint
- Multiple simultaneous goals ('recomp + tendon repair + cognition') — you'll never know what worked
Write the goal down. Write the endpoint measurement down. Write the timeframe down. This document exists before any peptide is chosen.
Step 2 — Choose the Primary Compound by Goal-Match, Then Tier
The primary compound is the one whose mechanism most directly addresses the goal. Prefer higher-tier compounds; only drop to lower tiers when the mechanism-fit is decisively better.
Map the goal to the mechanism, then to the compound. Some worked examples:
| Goal | Primary Mechanism | Primary Compound |
|---|---|---|
| Body-composition (metabolic obesity) | GLP-1/GIP agonism | Tirzepatide (Tier S) |
| Tendon repair | Angiogenesis + tissue-signalling | BPC-157 (Tier C) |
| Sleep / GH pulse | GHRH + GHS-R | Sermorelin or Ipamorelin |
| Cognitive recovery | BDNF / NGF-mediated | Dihexa or Semax |
| Mitochondrial function | Cardiolipin / ATP production | SS-31 or MOTS-c |
The tier note matters here: for goals where Tier S/A compounds exist and mechanism-match, use them. For goals where only Tier C/D compounds match (e.g. tendon repair — no licensed medicine exists), that's when a serious researcher accepts the lower tier and compensates with biomarker tracking.
Step 3 — Add Synergies That Aren't Redundant
A synergy adds a non-overlapping mechanism. If the second compound acts through the same pathway as the first, it isn't a synergy — it's a dose increase in disguise.
This is where accumulation gets ugly. The rule: every compound added must fill a specific mechanism gap the primary doesn't cover.
The canonical example is BPC-157 + TB-500 (the 'Wolverine Stack'). It works because:
- BPC-157 acts intracellularly via VEGF and growth-hormone-receptor pathways
- TB-500 acts extracellularly via thymosin-beta-4 actin regulation
- The two mechanisms are non-overlapping — you get additive effects rather than a redundant dose
Compare with a bad stack: sermorelin + CJC-1295 (with DAC). Both are GHRH-family compounds. Adding both is closer to a dose increase than a mechanistic synergy — and the DAC form's long half-life saturates the receptor in ways short-acting GHRH doesn't.
How to check for redundancy: list the mechanism of action for each candidate compound. If two compounds share the primary receptor or pathway, they're redundant. Add the second compound only if it acts on a genuinely different mechanism.
Cap at three compounds for a first stack. More than that and you lose the ability to attribute effects to specific components.
Step 4 — Choose Biomarkers You Will Actually Measure
For every goal, define baseline, mid-protocol, and endpoint measurements. If you can't (or won't) measure the biomarker, it doesn't count.
Every goal maps to biomarkers. Some are obvious, some require more thought:
| Goal | Primary Biomarkers |
|---|---|
| Body composition | DEXA scan, weight, waist circumference, HbA1c, fasting insulin, lipid panel |
| Tendon repair | Pain VAS score, loading capacity (heaviest tolerated exercise), functional test (single-leg heel raise reps) |
| GH/IGF axis | IGF-1, IGFBP-3, fasting glucose, HbA1c, sleep tracking data (deep sleep %, HRV) |
| Cognitive | Standardised cognitive test (Cambridge Brain Sciences or similar), subjective scores at fixed intervals |
The rule: baseline before you start, one mid-protocol check (typically week 4-6), and endpoint at protocol conclusion. See our bloodwork guide for the standard peptide panel.
If you're not going to measure anything, you're not running a research protocol — you're just taking peptides. That's a valid choice, but be honest about it.
Step 5 — Write the Stopping Rule Before You Start
Two stopping rules: the success rule (endpoint met, protocol ends) and the failure rule (predefined criteria for stopping early).
Success stopping rule: 'Protocol runs 12 weeks. If tendon pain VAS is < 2/10 and I can complete 15 single-leg heel raises pain-free, I stop.'
Failure stopping rule: 'If any of the following occur — new persistent symptom > 7 days, HbA1c rising > 5%, sleep quality dropping objectively for 2 consecutive weeks, unexpected weight change > 3 kg — I stop immediately and get labs.'
The failure rule matters more than the success rule. Almost no one writes it down. Everyone should. It exists to protect you from motivated reasoning three weeks into a protocol that isn't working (or is causing side effects).
Step 6 — Cycle Length and Off-Cycle Planning
Most peptide protocols are 4-12 weeks. GH secretagogues need genuine off-cycles. Repair peptides can run continuously through recovery, then stop.
Rules of thumb by class:
- GH secretagogues (sermorelin, ipamorelin, CJC-1295): 4-8 weeks on, minimum equal time off. Continuous use causes pituitary desensitisation.
- Repair peptides (BPC-157, TB-500): run for the duration of the injury recovery, typically 4-8 weeks, then stop. No benefit to indefinite use once tissue has healed.
- GLP-1 agonists (semaglutide, tirzepatide): these are chronic-use medications for chronic metabolic disease. Not 'cycled' in the traditional sense — clinical maintenance.
- Longevity peptides (epitalon, MOTS-c, humanin): typically pulsed protocols (10-20 days on, 2-3 months off). The evidence for optimal frequency is thin.
Never overlap cycles of the same class. If you're finishing an ipamorelin cycle, don't start CJC-1295 the next day.
Frequently Asked Questions
Start with one primary compound. Add a synergy only if it addresses a mechanism the primary doesn't cover. Cap at three compounds for a first stack — beyond that, you lose the ability to attribute effects, and interaction risks compound. Experienced researchers occasionally run four, but only when each mechanism is genuinely non-overlapping and the biomarker tracking is rigorous.
The most defensible beginner stack is a single compound with clear goal-match and Tier B or higher evidence. BPC-157 alone for tissue repair, sermorelin alone for sleep/GH, or semaglutide alone for metabolic goals. Add a second compound only after you've completed one full cycle solo and know how you respond.
You defined biomarkers in Step 4. Compare baseline to mid-protocol and to endpoint. If the primary biomarker hasn't moved meaningfully by mid-protocol, the stack likely isn't working — either the compound isn't effective for you or the mechanism doesn't match the goal. Don't wait to endpoint to reassess.
Not recommended for a first attempt. Tier D compounds have limited human safety data individually. Combining them multiplies the unknown-interaction risk. If you're going to use a Tier D compound, do it solo with rigorous biomarker tracking first — that gives you a clean read on its individual effect and safety.
Depends on class. For GH secretagogues, minimum equal-time off between cycles. For repair peptides, once the tissue has healed, indefinite off. For longevity peptides, follow the specific compound's protocol (epitalon: 10-20 days on, 2-3 months off). Never rush the off-cycle to chase feeling good — you're managing receptor sensitivity and long-term axis function.