A peptide is a short chain of amino acids, the same building blocks that make up proteins, joined end to end by a single kind of chemical link called the peptide bond.
One amino acid is a monomer. Join two and you have a dipeptide. A chain of roughly two to fifty amino acids is a peptide; longer than that, and the chain folds into a protein. So a peptide is a protein fragment small enough to act like a precise instruction rather than a machine. Two amino acids link when the acid end of one bonds to the amino end of the next and a molecule of water is released. The chain has an amino end (N-terminus) and an acid end (C-terminus); the order read from N to C decides its shape and which receptors it fits.
Most peptides here are messages, not structure. The body already runs on them: insulin, glucagon, oxytocin, and the incretin GLP-1 are all peptides. Each reaches a matching receptor and triggers a response. A peptide's small size lets it bind with high specificity while slipping through tissue more easily than a bulky protein, which is why drug makers chase them.
The digestive tract breaks proteins into amino acids, so a swallowed peptide is mostly dismantled before it can act, and the little that survives is filtered by the liver on first pass. A subcutaneous injection sidesteps all of that, which is why it is the default. Exceptions exist: oral semaglutide pairs the peptide with an absorption enhancer, and orforglipron sidesteps the problem by being a small molecule rather than a peptide.
Signals are meant to fade, so the body clears many peptides in minutes. Attaching a fatty-acid chain lets a peptide ride along on albumin for days (how semaglutide and tirzepatide reach weekly dosing). Other tricks: PEGylation, mirror-image D-amino acids enzymes cannot grip, and cyclizing the chain into a closed loop.
Peptides are assembled by solid-phase synthesis (anchor the first amino acid to a resin bead, then add the rest one at a time) or produced in engineered cells. The finished product is never perfectly clean: truncated chains, wrong residues, leftover solvents, and endotoxin can all ride along, which is why the certificate of analysis matters as much as the label.
The shorthand this guide leans on, in one place.
Every record carries a second, functional color on its left and top edge and its chip, alongside its class numeral. This groups compounds by what they actually do, cutting across the seven categories.
Which functions appear inside each of the seven classes, with record counts. A class can span several functions, and a function can span several classes.
Records with a matching page on PeptideDosingProtocols.com carry a SubQ dosing reference with U-100 syringe conversions for 2 mL and 3 mL bacteriostatic water. This note covers the technique that sits behind every one of those tables.
Clinical trial User research No human data Every protocol in this guide is tagged with where its dose comes from. Clinical trial: a regulatory label (FDA, EMA, China, Japan, Russia) or a published, registered human trial. User research: community consensus averaged from Reddit and biohacking boards plus vendor reference sites, not a formal trial. No human data: the compound is preclinical or a lab reagent with no established human dose, shown for reference only. A record can carry more than one tag, for example both Clinical trial and User research, when a formal trial dose and a community consensus both exist.
Lyophilized powder is the stable form: frozen (-20 °C), dry, and dark for long-term holding. Reconstituted solution is fragile: refrigerate (2–8 °C) and use within roughly 2–4 weeks (28 days is the common default), never freeze it. Multi-dose vials need bacteriostatic water (0.9% benzyl alcohol), not plain sterile water or saline.
On a U-100 syringe, 100 units = 1 mL, so 1 unit = 0.01 mL. concentration = vial mg ÷ water mL, and units = dose ÷ (concentration × 0.01). A 10 mg vial in 2 mL is 5 mg/mL, so a 250 mcg (0.25 mg) dose is 5 units; the same vial in 3 mL is 3.33 mg/mL, so 250 mcg becomes 7.5 units.
These are research-planning references, not prescriptions. Where a compound's documented route is not subcutaneous (oral tesofensine, IM/IV cerebrolysin and glutathione), the entry says so instead of inventing a SubQ protocol. For approved drugs the FDA label governs, and the community figures shown never override it.
Reading "SKU" codes. Single-compound vials are usually [abbreviation][number], where the number is the milligram content: BPC10 is sold as 10 mg of BPC-157. That is total peptide in the vial, not a concentration. Blends drop the chemistry for a catchier name (GLOW50, KLOW80). Vendor letters carry no standard meaning.
Storage. Powder is the stable form: lyophilized, kept cold and dark, an unopened vial can last months to years, best frozen once. Reconstituted means fragile: refrigerate and use within a short window (commonly a few weeks). Cloudiness, particles, or color shift mean discard.
| Appearance | White powder | Conforms |
| Identity (LC-MS) | [M+H]+ 1420.6 | Conforms |
| Purity (HPLC) | 98.7% | ≥95% |
| Net peptide | 5.08 mg | Label 5 mg |
| Sterility / endotoxin | Not included | Not requested |
What a certificate does and does not tell you. Identity and purity are two different tests (mass spec confirms the molecule; HPLC measures how much is that molecule). >99% purity is the peptide fraction only and says nothing about sequence, fill weight, or sterility. Check who signed it and that the lot number matches the vial. A third-party lab beats an in-house sheet. Sterility and endotoxin are usually missing, and they matter most for anything injected.
The same building blocks. BPC-157, TB-500, GHK-Cu, and KPV keep reappearing inside blends; GLOW, KLOW, and "Wolverine" are remixes with no new chemistry and no compounding status of their own.
Not all are peptides. SLU-PP-332, 5-Amino-1MQ, MK-677, and AICAR are small molecules or non-peptide mixtures sold under the same banner.
One step from a drug. PT-141 and Melanotan II share a lineage; Melanotan I shares a sequence with the approved implant Scenesse. That does not make the loose vials approved or standardized.
Community demand comes first. Forums usually form a compound's reputation months or years before a trial or PCAC nomination; regulators largely react to demand.
The same grey-market channels also move drugs that are far more dangerous. Opioid peptides like dermorphin run many times stronger than morphine. Insulin and EPO kill with some regularity when self-dosed. Human growth hormone and its fragments, and the fertility gonadotropins (hCG, HMG) are sold for self-managed hormone cycles. And grey-market botulinum toxin, the most potent toxin known, has put users in the hospital with botulism.
None of these belong in a source-it-and-inject-yourself workflow; several can be fatal on a single mistake. If you are weighing any of them, that is a conversation for a physician, not a vendor.