A working laboratory reference covering receiving and inspection, reading the lyophilized cake, concentration maths, reconstitution technique, storage before and after, diluent selection, and how to actually read a certificate of analysis.
Research use only. This reference covers handling the material — it does not provide dosing, administration or protocol guidance.
Research peptides ship as lyophilized powder — freeze-dried under vacuum, with the water removed by sublimation rather than heat. That process is what makes the material stable enough to survive ambient shipping, and it is why no cold chain is needed in transit.
The first thing to do on arrival is nothing at all. Let the package reach room temperature before opening anything. A vial that has been in a cold delivery vehicle will pull condensation the moment it hits warm indoor air, and moisture is the one thing lyophilized peptide cannot tolerate.
Photograph the vial and packaging before you do anything else if something looks wrong. A single photo taken on arrival resolves almost every replacement claim immediately; one taken a week later resolves very few.
The lyophilized cake tells you a surprising amount before any solvent goes near it. A correctly freeze-dried peptide forms a solid, uniform plug that holds the shape of the vial base — usually white to off-white, sometimes with a faint sheen.
Some visual variation is normal and means nothing. Cake volume differs between compounds and between fill weights, so a 2mg vial looking sparse next to a 10mg vial is expected, not a fault. A cake that has cracked or partially collapsed during shipping is cosmetic and does not affect the material.
Moisture is the failure mode that matters. A tacky or visibly damp cake means the seal was compromised at some point, and the material should not be used regardless of how it looks otherwise.
Concentration is the part people overthink, and it comes down to one relationship: concentration equals mass divided by volume. The peptide mass in the vial is fixed and printed on the label. The only variable you control is how much diluent you add.
A 10mg vial reconstituted with 2mL of bacteriostatic water gives 5mg/mL. The same vial with 1mL gives 10mg/mL. The quantity of peptide never changes — only how dilute it is.
| Vial | Diluent added | Resulting concentration |
|---|---|---|
| 5mg | 1mL | 5mg/mL |
| 5mg | 2mL | 2.5mg/mL |
| 10mg | 1mL | 10mg/mL |
| 10mg | 2mL | 5mg/mL |
| 10mg | 5mL | 2mg/mL |
| 50mg | 5mL | 10mg/mL |
Lyophilized powder adds negligible volume, so the diluent volume and the final solution volume can be treated as the same number. That approximation holds comfortably at these scales.
Working out concentration by hand is fine, but the calculator does it instantly and also converts to units on a U-100 syringe, which is where most arithmetic mistakes actually happen.
Enter your vial size and diluent volume and the calculator returns the concentration, plus what that works out to per unit on a U-100 syringe.
Open the reconstitution calculatorReconstitution is a short procedure with a few points where technique genuinely matters. Peptides are fragile in ways that small molecules are not — mechanical shear and aeration both degrade them, and neither leaves any visible sign that it happened.
If a solution will not go clear after several minutes of standing, stop. Do not shake it to force dissolution — that will not fix a genuine problem and will damage material that might otherwise have been fine.
A small number of compounds specify a different diluent. IGF-1 LR3 protocols sometimes call for dilute acetic acid at the solubilisation step rather than bacteriostatic water. Where a protocol specifies a diluent, follow the protocol rather than the general rule.
Storage requirements change completely once a vial is reconstituted. Dry powder is robust; solution is not.
| State | Temperature | Practical shelf life |
|---|---|---|
| Lyophilized, sealed | −20 °C | 24+ months |
| Lyophilized, sealed | 2–8 °C | ~12 months |
| Lyophilized, sealed | Room temperature | Weeks — transit only |
| Reconstituted, bacteriostatic water | 2–8 °C | ~3–4 weeks |
| Reconstituted, sterile water | 2–8 °C | Same session |
Each freeze-thaw cycle causes measurable degradation. If reconstituted material needs to be held long-term, divide it into single-use aliquots before freezing rather than repeatedly thawing and refreezing one vial. The difference compounds quickly.
Protect from direct light in both states. For sealed powder, humidity is the greater risk than temperature — keep vials in their original packaging with any desiccant left in place, and avoid storing them anywhere humidity swings, which rules out most bathrooms and unheated garages.
The two look identical and are not interchangeable. The difference is one ingredient and it decides how long your solution lasts.
| Bacteriostatic water | Sterile water | |
|---|---|---|
| Contains | 0.9% benzyl alcohol | Nothing — water only |
| Multi-access | Yes | No |
| After first pierce | ~28 days refrigerated | Same session |
| Use when | Solution will be stored | Single-session work only |
Benzyl alcohol is bacteriostatic rather than bactericidal — it inhibits bacterial multiplication rather than killing organisms outright. That is sufficient for a vial accessed several times over a few weeks, and it uses a far lower preservative concentration than a bactericidal approach would need.
A reconstituted peptide solution is an excellent growth medium. Without a bacteriostatic agent, anything introduced when the stopper is pierced has ideal conditions to multiply. That is the entire reason the preservative exists.
A certificate of analysis is the document that separates verified material from a claim on a website. Knowing how to read one is worth more than any purity figure printed on a product page.
Purity and identity answer different questions, and either alone is insufficient. HPLC tells you how much of the sample is the target compound versus synthesis by-products and truncated sequences. Mass spectrometry tells you whether the target compound is the one it should be.
A sample can be 99% pure and still be entirely the wrong peptide. Purity figures quoted without identity confirmation are the most common way a specification sheet manages to be technically accurate and practically meaningless.
A COA that does not carry a lot number matching your vial is not documentation of your material. Generic certificates reused across batches are common in this market and are worth roughly nothing.
The list is short, and most of it is inexpensive.
| Item | Purpose |
|---|---|
| Bacteriostatic water | Standard diluent for stored solutions |
| Alcohol swabs | Wipe the stopper before each access |
| U-100 syringes | Measurement; the unit markings are the practical scale |
| Sharps container | Disposal |
| Refrigerator | 2–8 °C for reconstituted material |
| Freezer | −20 °C for long-term storage of sealed powder |
| Marking | Volume | Also written as |
|---|---|---|
| 10 units | 0.10 mL | one tenth of a 1mL syringe |
| 20 units | 0.20 mL | one fifth |
| 50 units | 0.50 mL | half |
| 100 units | 1.00 mL | the full syringe |
Wipe the stopper with an alcohol swab before every access, not just the first. The preservative in bacteriostatic water handles what gets in; it does not excuse introducing more each time.
Third-party HPLC and LC-MS on every lot, with the certificate matched to the lot number printed on your vial.
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