Running a Peptide Protocol: The Parts
A protocol is five separate problems people treat as one: evidence, frequency, concentration, stability and site. A map of each, and where they connect.
Almost everything written about peptides treats a protocol as a single subject. It is not. It is five different problems that happen to arrive together, each with its own failure mode, and most of the confusion in this area comes from answering one of them while thinking you have answered another.
This page is the map. Each section links to the article that covers it properly.
1. What the compound is, and what actually supports it
This is the question everything else depends on, and it is the one most often answered by marketing copy.
The useful distinction is not “does it work” but what kind of evidence exists:
| Evidence tier | What it means | Examples on this site |
|---|---|---|
| Approved, large trials | Regulator-assessed, with published phase III outcomes | Semaglutide, Tirzepatide |
| Approved in one jurisdiction only | Clinically used somewhere, unassessed elsewhere | Semax |
| Human research, no approval | Real trials for specific formulations and indications | TB-500 / thymosin β4 |
| Preclinical only | Cells and animals; no completed human efficacy trial | BPC-157, MOTS-c, KPV |
| Narrow, largely unreplicated | Findings concentrated in one group or journal | Epitalon |
Two recurring traps live in this table. The first is fragment substitution — claims for a full protein being attached to a short synthetic piece of it, which is the entire story of TB-500. The second is direction reversal: exercise raising a peptide is not evidence that injecting the peptide reproduces exercise, which is the story of MOTS-c.
For anyone who competes, there is a separate question that has nothing to do with evidence: the WADA Prohibited List covers several of these compounds at all times, and a therapeutic use exemption is not available for substances with no approved therapeutic use.
2. How often — and why that is not arbitrary
Injection frequency is not a preference. It is set by how long the molecule survives in circulation, which is a property of the molecule and of what has been done to it.
Semaglutide is injected weekly because fatty-acid modification lets it bind albumin, which holds it as a reservoir. An unmodified peptide can be gone in minutes. Same class of molecule, schedules three orders of magnitude apart.
→ Peptide half-life: why schedules differ
3. From a vial to a measured dose
This is arithmetic, and it is where a mistake produces an error of a factor of ten rather than a small inaccuracy.
The number that matters is concentration — how much peptide per millilitre — because the vial’s label and the syringe’s markings are in different units and neither one is the dose.
→ Reconstitution and concentration: the arithmetic → Reconstitution calculator to run your own numbers
4. Keeping the material intact
Peptides are fragile in a specific, well-characterised way. Heat, light, freeze-thaw cycles and agitation each degrade them by a different mechanism, and the moment water enters the vial the shelf life changes from years to weeks.
This failure is silent. Degraded material looks identical, so the record says one dose was administered while the body received less.
→ Peptide storage: what actually degrades them
5. Where the injection goes
Repeatedly injecting into the same small area produces lipohypertrophy — thickened tissue that absorbs unpredictably. The evidence base comes from insulin therapy, where roughly one in three participants in a worldwide survey appeared to be affected.
It is painless, easier to feel than to see, and the affected area is slightly less sensitive — which makes it more comfortable to keep using, which is how it grows.
→ Injection site rotation and lipohypertrophy
What connects them
Three of these five — concentration, degradation and absorption drift — end in the same place: the dose that reached the body is not the dose in the record. They have different causes and one shared consequence, and none of them announces itself.
That is the argument for keeping records that are more precise than memory. Not because a log makes any compound work, and not because tracking substitutes for evidence — it does not, and for most of the compounds above the evidence is thin. It is that if you cannot say what you actually did, you cannot learn anything from having done it.
Four of the five above are record-keeping problems, and PeptCycle covers those four: the schedule, the concentration a vial was made up to, the state of the material and the site each dose went into.
The first one is not, and no app can make it so. Whether the evidence supports the compound at all is a question you answer before any of this becomes relevant — which is why the app takes no position on it, and why there are no dose recommendations anywhere on this site.
Frequently asked questions
What does a peptide protocol actually consist of?
Five separable problems: what the compound is and what evidence supports it, how often it is administered, how a vial becomes a measured dose, how the material is kept intact, and where the injection goes. They are usually discussed as one topic, which is why individual mistakes are hard to spot.
Which part goes wrong most often?
The two that are silent. Degradation from poor storage and drift in absorption from injecting into the same area both fail without any signal — nothing looks wrong at the time, and the consequence is a dose that is not what the record says it was.
Does this page tell me what to take or how much?
No. There are no dose recommendations anywhere on this site. This page maps the mechanics that apply once a protocol already exists, and dosing is a decision for a doctor.