Reconstitution
Peptide Reconstitution: Units, Math, Step-by-Step
Published by Peptara Labs · Updated · How we research and check our pages
Reconstitution turns a freeze-dried peptide vial into an injectable solution. Every peptide vial ships as a freeze-dried powder. Before first use the powder is mixed with bacteriostatic water, a process called reconstitution. The math is simple, but the wrong unit (mL versus units on the syringe) is the most common source of 10x overdoses in self-administered protocols.
The short answer
To reconstitute a peptide, wipe both rubber stoppers with alcohol, then inject bacteriostatic water slowly down the inner wall of the freeze-dried vial and swirl gently until the liquid runs clear, never shake it. Then work in insulin-syringe units, not mL: the calculator on this page turns a vial size, bac water volume and target amount into a unit count, so there is no decimal place to misread.
Why units, not mL
Published research figures are reported on this site in insulin-syringe units, never in mL. Reading a decimal place wrong on a small syringe barrel can mean a 10x overdose. Reading the wrong tick mark cannot. The only mL number on this page is the bac water input volume.
The 4-step method
Total time: about 5 minutes. Reusable across every peptide in the Peptara catalog.
Wipe vial top with alcohol
Wipe the rubber stopper of both the peptide vial and the bacteriostatic water vial with a fresh alcohol swab. Let each surface air-dry for a few seconds. This is the single biggest contamination guard in the whole process.
Draw bac water with syringe
The plunger of a U-100 insulin syringe is pulled to the bac water volume planned for the vial (the recommended volume table below has presets for every Peptara SKU). The needle goes into the bac water vial and the water is drawn cleanly.
Inject slowly down the side of the vial wall
The needle enters the peptide vial at an angle so the bac water runs down the inner glass wall, not directly onto the lyophilized powder. A slow stream protects fragile peptide bonds and keeps the solution clear.
Swirl gently, do not shake
The vial is rolled between the palms or swirled on a flat surface until the powder is fully dissolved. Shaking creates foam and can fragment the peptide. The solution should look clear within 30 to 60 seconds.
Reconstitution math (units, not mL)
One universal formula handles every peptide in the catalog.
The formula
units = (desired dose in mg / vial strength in mg) × (bac water in mL × 100)
A U-100 insulin syringe holds 100 units per 1mL. So 1mL of reconstituted solution equals 100 units. If you put 10mg of peptide into 1mL of bac water, each unit delivers 0.1mg (100mcg).
Worked examples
Retatrutide
20mg vial, 2mL bac water, 5mg example amount. (5 / 20) × (2 × 100) = 50 units on the syringe.
Tirzepatide
20mg vial, 2mL bac water, 5mg example amount. Same math as Retatrutide: 50 units on the syringe.
BPC-157
20mg vial, 2mL bac water, 250mcg (0.25mg) example amount. (0.25 / 20) × 200 = 2.5 units, round up to 3 units on the syringe.
Calculator
Pick a vial from the Peptara catalog (or enter a custom strength), set the bac water volume, and enter a target amount in mg. The calculator returns the unit count and shows where to draw on a U-100 insulin syringe. If you are working from a vial that is not in our catalog, the standalone peptide reconstitution calculator takes any vial strength and volume and prints its working.
Educational reference, not a prescription and not a personal dose. This tool converts a concentration into syringe units so you can check the math. It does not set a dose or tell you how to inject. A licensed clinician sets any dose and administration.
Equivalent on a U-100 syringe
50units
At this concentration, 5 mg of peptide occupies about 50 units of volume on the U-100 scale. This is reconstitution arithmetic for handling the vial, not a dose, a draw, or an instruction for anyone.
Recommended bac water volumes
Default reconstitution presets for every Peptara Labs SKU. The example amounts are round figures picked to make the unit arithmetic easy to follow, not a recommendation for any vial, any compound or any person. A licensed clinician sets any dose.
Peptide reconstitution chart
Read this peptide reconstitution chart as a math illustration only: each row shows how a vial size and a 2mL bac water fill convert an example amount into syringe units. It is not a dose for anyone, and nothing here picks one.
| Peptide | Vial size | Bac water | Example amount (not a recommendation) | Units per example amount |
|---|---|---|---|---|
| Retatrutide | 20mg | 2mL | 5mg | 50 units |
| Tirzepatide | 20mg | 2mL | 5mg | 50 units |
| BPC-157 | 20mg | 2mL | 250mcg | 3 units |
| CJC-1295 / Ipamorelin | 10mg | 2mL | 250mcg | 5 units |
| GHK-Cu | 100mg | 2mL | 2mg | 4 units, draw slowly: at 50mg/mL a single unit is 0.5mg |
| TB-500 | 10mg | 2mL | 2.5mg | 50 units |
| MT-2 (Melanotan-2) | 10mg | 2mL | 0.5mg | 10 units |
| Semax | 10mg | 2mL | 600mcg | 12 units |
| Selank | 10mg | 2mL | 600mcg | 12 units |
| KLOW Combo | 80mg | 2mL | 4mg | 10 units |
| MOTS-c | 40mg | 2mL | 5mg | 25 units (matches JP protocol Section 06) |
| Epithalon | 50mg | 2mL | 1mg | 4 units, draw slowly: at 25mg/mL a single unit is 0.25mg |
| Tesamorelin | 20mg | 2mL | 2mg | 20 units |
| SLU-PP-332 | 5mg | 2mL | 1mg | 40 units |
| PT-141 (Bremelanotide) | 10mg | 2mL | 1.5mg | 30 units |
| Glutathione | 600mg | 2mL | 200mg | 67 units at 300mg/mL, drawn across one syringe |
Figures shown for math illustration only. They are not a dose for anyone, and nothing on this page picks one.
Storage
Before reconstitution
Stable at room temperature
Lyophilized peptide powder is stable at room temperature for weeks and in a freezer for many months. Keep the vial sealed and out of direct sunlight until the day you reconstitute.
After reconstitution
Refrigerate immediately
Once mixed with bac water, store the vial at 2 to 8 Celsius. 30-day shelf life is the safe default for most peptides. The per-compound pages carry the per-peptide detail.
Travel
Reconstituted vials travel with an ice pack in carry-on. Lyophilized vials handle cabin temperature without ice. Country-specific customs rules vary, see the FAQ for travel guidance.
Frequently asked questions
How much bac water should I use?
Use 2mL of bacteriostatic water for every vial in the table on this page. One volume for every compound removes the failure where a remembered volume from one vial gets applied to another. The volume sets the concentration, which sets how many units one dose becomes. The math stays consistent because figures are reported in units, not mL.
Why units instead of mL?
A U-100 insulin syringe is calibrated in units (100 units = 1mL). Drawing 0.1mL on a small barrel is hard to read accurately. Drawing 10 units is unambiguous because the unit ticks are clearly visible. Switching the dose language from mL to units removes the most common source of accidental 10x overdoses: misreading a decimal place.
What if I draw a different bac water volume than recommended?
The math still works, you just get a different concentration. Less bac water means each unit delivers more peptide (so fewer units per dose). More bac water means each unit delivers less (so more units per dose). The calculator on this page recomputes the unit count for any bac water volume you enter.
Can I shake the vial to dissolve faster?
No. Shaking foams the solution and can denature the peptide, especially with fragile compounds like BPC-157, CJC-1295, and Ipamorelin. The standard technique rolls the vial gently between the palms or swirls it on a flat surface. Full dissolution should take 30 to 60 seconds.
Why is my peptide cloudy after reconstitution?
A correctly reconstituted vial turns clear within about 30 to 60 seconds of gentle swirling. Short-lived cloudiness usually means the powder has not fully dissolved yet, or that shaking whipped foam and micro-bubbles into the solution, both of which settle out on their own. Persistent haze, floating particles, or a solution that will not go clear is a reason to stop and not use that vial.
How long does reconstituted peptide last?
Pre-reconstitution: lyophilized powder is stable at room temperature for weeks and in a freezer for many months. Post-reconstitution: refrigerate immediately at 2 to 8 Celsius and use within 30 days for most peptides. Some peptides (TB-500, BPC-157) hold for slightly longer; others (Tesamorelin) degrade faster. The per-compound pages carry the per-peptide shelf life.
What if my syringe only goes up to 40 or 50 units?
You probably have a U-40 syringe or a half-cc U-100 syringe. Half-cc U-100 syringes hold 50 units and are fine for most volumes (the units math is identical). U-40 syringes are a different scale entirely and will read incorrectly unless converted. Every figure on this site is reported on the U-100 scale.
Do you include bac water?
Your kit includes the vials and bacteriostatic water. Insulin syringes ship with your order to select delivery regions; where they can't ship, we send a same-day sourcing link. A printed reference guide ships with every order. We confirm exactly what is included with your order.
What is the safest way to learn reconstitution technique?
Reconstitution is arithmetic on concentration plus sterile technique. The calculator on this page does the math and reports the result in units rather than mL, which is the reading that cannot be misread by a factor of ten. The team is on WhatsApp for questions about the vial, the volume and storage. Anything about administration belongs with a licensed physician.
Peptide pages
Retatrutide
Triple-agonist GLP-1 / GIP / glucagon. Studied in clinical trials for weight loss.
View page
Tirzepatide
Dual-agonist GLP-1 / GIP. Studied in clinical trials for weight loss.
View page
BPC-157
Body Protection Compound for tissue repair, gut healing, recovery.
View page
Compound-specific guides
How to reconstitute retatrutide
The 20mg vial start to finish, what bac water is, how much to add, and the units math worked out at 1 mL, 2 mL and 3 mL.
Read the guide
Order with reconstitution math built in
The concentration math for every vial we sell, worked out on this page, in units rather than mL.
Every Peptara Labs order includes bac water sized to the vial, a printed reference, and support on WhatsApp for the vial, the volume and storage.