Learn · How to

How to reconstitute a peptide vial.

Seven steps from sealed vial to first injection. Done right, you get a 28-day supply of stable, sterile peptide. What actually matters is clean technique and proper storage — not babying the powder.

Educational reference. These are the standard handling and sterile-technique steps research peptide users follow. Whether (and how) to inject any compound is a decision for you and your physician — not something this guide makes for you.

What you need

Per session

Don't have all this on hand? The Tide Kit ships with everything except the peptide itself — 20 insulin syringes, 5 recon needles, 20 alcohol wipes, BAC water vial, and an insulated case for $59.

The 7 steps

Wash hands and prep your workspace

Wash hands thoroughly with soap. Lay out a clean alcohol wipe, the peptide vial, BAC water vial, syringe, and reconstitution needle on a flat clean surface.

Wipe both vial septums

Use one alcohol prep wipe on the peptide vial top, another on the BAC water vial top. Let them air-dry for ~10 seconds. Don't blow on them — that re-contaminates.

Attach the 18G reconstitution needle to your syringe

Twist the 18G needle onto the syringe hub. The larger gauge handles the rubber septum without dulling. The insulin syringe's fixed 29G needle would bend.

Draw BAC water

Insert the 18G needle into the BAC water vial. Pull back air equivalent to the volume you'll draw (this prevents vacuum). Invert the vial, draw the BAC water slowly to your target volume (typically 1 mL per 10 mg of peptide). Withdraw the needle.

Inject BAC water into the peptide vial — down the SIDE WALL

Insert the needle into the peptide vial. Angle it so the stream runs down the inside wall of the vial — aiming down the wall keeps foaming down. A little landing on the powder is fine; it won't hurt the peptide. Once empty, withdraw the needle.

Mix until it's dissolved

Swirl or roll the vial in your palm until the powder dissolves, usually under a minute, leaving a clear or pale liquid. A shake works too — peptides handle normal mixing fine. The only catch is foam: if it foams up, let the bubbles settle for a few minutes before drawing so your dose measures accurately.

Mark the recon date and refrigerate

Write today's date on the vial label with a fine permanent marker (your 28-day BUD clock starts today). Store at 2–8°C — refrigerator, not freezer. Don't freeze a reconstituted vial; the freeze-thaw cycle damages most peptides irreversibly.

Critical don'ts: Don't reuse the recon needle. Don't freeze a reconstituted vial. Don't use plain sterile water (no preservative — limits you to 24 hours). Shaking is fine — just let any foam settle before you draw.

Storage and shelf life

After reconstitution, refrigerate at 2–8°C (the back of the fridge, not the door). The 28-day beyond-use date (BUD) is the standard limit when reconstituted with bacteriostatic water — the benzyl alcohol preservative keeps the vial safe for that long. After 28 days, discard.

If you ordered the peptide and aren't using it yet: the lyophilized (dry) powder can be stored in the freezer for months, or in the fridge for weeks. Once you reconstitute, the 28-day clock starts.

Compute your dose, then inject

Now that your vial is reconstituted, you need to know how many insulin units to draw for your dose. Two tools handle the math:

Free · No signup
Web dose calculator
Pick a peptide, enter your vial and water, get the exact units for your target dose.
Free PWA · Installable
Goodtides Companion
Calculator + injection log + vial countdown so you know exactly when to start a new one.

For the actual injection: pinch a fold of subcutaneous fat (usually abdomen, 1–2 inches from navel), insert the 29G needle at 45–90° depending on your subQ depth, push the plunger slowly, withdraw, and press an alcohol wipe over the site for 5 seconds. Rotate injection sites with every dose to avoid lipohypertrophy (the tissue thickening that happens at over-used sites).

Frequently asked

What is bacteriostatic water and why do I need it?
Bacteriostatic water (BAC water) is sterile water with 0.9% benzyl alcohol added as a preservative. The benzyl alcohol prevents bacterial growth, letting the reconstituted vial stay safe for up to 28 days under refrigeration. Plain sterile water lacks the preservative — limited to 24 hours, useless for multi-dose vials.
How much bacteriostatic water do I add to a peptide vial?
Standard is 1 mL of BAC water per 10 mg of peptide (1:1 mg-to-mL ratio → 10 mg/mL concentration). Exceptions: Selank/Semax recon at 2 mL for a 5 mg/mL concentration; KLOW recons at 3 mL for 26.7 mg/mL of total blend. When in doubt, check the dose calculator — it shows the recommended recon for every peptide in the catalog.
How long does a reconstituted vial stay good?
28 days at refrigerator temperature when reconstituted with bacteriostatic water. Mark the recon date on the vial. After 28 days, discard the remainder — preservative efficacy drops and bacterial risk rises. The Goodtides Companion app tracks BUD automatically once you log a vial; you'll get a notification when it's about to expire.
Can I freeze a reconstituted vial?
No. Freezing damages most peptides through the freeze-thaw cycle — crystallization disrupts the protein structure. The dry lyophilized powder can be frozen for months, but once you've added water, you're locked into the 28-day refrigerated window.
Can I shake the vial?
Yes — research peptides tolerate normal handling, and a shake won't ruin them. The only reason to favor a gentle swirl is foam: bubbles make it harder to draw an accurate dose. Mix it however you like; if it foams, let the bubbles settle a few minutes before you draw.
What if my peptide doesn't dissolve?
Most peptides dissolve in under a minute of swirling. If you see undissolved powder after 5 minutes: wait another 5, roll the vial between palms, or warm it in your hand to body temperature. If still undissolved after 15 minutes the peptide may be degraded — contact the supplier. Never heat above body temperature.
Do I need separate needles for reconstitution and injection?
Yes. Use an 18G reconstitution needle to draw BAC water (large gauge punches the septum cleanly without dulling), then switch to a 29G insulin syringe for the actual subQ injection. Never inject with the 18G — it's too thick and painful. The Tide Kit ships with 5 recon needles + 20 insulin syringes.

For research peptide users tracking their own protocol. Not medical advice. Peptides referenced here are research chemicals, not FDA-approved drugs. Consult a qualified clinician for medical decisions.