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Research Peptides Calculator
Peptide Reconstitution & Dosage Calculator
The purpose of this calculator is to answer two simple questions: how much liquid (bacteriostatic water) should researchers mix into the peptide vial, and how far to pull back the syringe?
Quick-fill a common peptideLoads a typical vial size, BAC water volume, and dose as a starting point — edit any value below.
These are commonly listed starting reference values only, not a recommendation — always confirm against your product's certificate of analysis / label before use.
1
What is the total volume of your syringe?
✓
0.3 ml
30 Units
0.5 ml
50 Units
1.0 ml
100 Units
2
Peptide Vial Quantity
✓
mg
3
Bacteriostatic Water
✓
ml
4
How much peptide do you want in each dose?
✓
mcg
🧬
Complete all four steps above
to see your exact calculated dose.
Your Calculated Result
For a dose of — mcg,
pull to unit —
That's — ml drawn in a — ml syringe
Syringe Fill Level
0%
—Concentration
—Volume / Dose
—Syringe Units
—Doses per Vial
⚠️ Required volume exceeds your — ml syringe. Choose a larger syringe, add more water, or lower your dose.
How the peptide reconstitution formula works? OR How the Peptide Calculator Works?
The research peptide calculator can accurately measure the required dose for lab use. However, researchers don't need to do these calculations. Here is how the calculator works, let’s see it's not guess numbers.
Peptide suppliers ship peptides as freeze-dried substances in the vial, not a liquid. Before researchers can measure it with a syringe, they need to add a liquid (bacteriostatic water) so it dissolves. Once the calculator gets three things, it works out the rest for you:
- How much peptide is in the vial: the amount printed on the vial's label, in mg.
- How much liquid you're adding: the amount of bacteriostatic water you mix in, in ml.
- How much you want per use: your target dose, in mcg or mg.
Reconstituting a lyophilized (freeze-dried) peptide means adding a liquid — almost always bacteriostatic water — to the powder in the vial so it can be measured and drawn into a syringe. Once you know three numbers, the rest of the math is fixed:
- Vial size (mg) — the total peptide mass printed on the vial label.
- Bacteriostatic (BAC) water added (ml) — how much liquid you draw into the vial.
- Target dose (mcg or mg) — the amount you intend to draw per use.
From those three inputs, the calculator above solves:
Concentration (mcg/ml) = vial mg × 1000 ÷ water ml
Draw volume (ml) = target dose (mcg) ÷ concentration (mcg/ml)
Syringe units = draw volume (ml) × (syringe units ÷ syringe ml)
(100 is used because most syringes are marked in 100 units per 1 ml, if yours is a different size, the calculator adjusts this automatically.)
For example, a 5 mg vial mixed with 2 ml of BAC water gives a 2,500 mcg/ml concentration. A 250 mcg dose then equals 0.1 ml, which reads as 10 units on a standard 1 ml (100‑unit) insulin syringe.
Reconstituting your Vial | OR -- How to Mix Bacteriostatic Water with Peptide: Step-by-Step Process!
- Sanitize both stoppers / Wipe both vials: Use an alcohol gauze on the rubber top of the liquid (bacteriostatic water) bottle and the peptide vial before you stick a needle into either one.
- Draw the water first / Fill the syringe with liquid first: Before touching the peptide vial, pull the amount of water first into the syringe according to the reading of the calculator.
- Add it slowly, down the wall (down the glass slowly):Aim the needle at the inside wall of the vial, not straight down at the peptide. Push the bacteriostatic water in gently.
- Swirl — don't shake. (Roll it, don't shake it):Cup the vial in your hands and roll it gently until the peptide is fully dissolved and the liquid looks clear. Shaking can ruin the dose.
- Label and refrigerate (Write the date on it, then refrigerate): Once it's mixed, write today's date on the vial and store it in the fridge, away from light. Follow whatever your product's own instructions say about how long it's good for.
Reference: Typical/Common Vial Sizes by Peptide
This table shows commonly used vial sizes seen across research peptide suppliers. However, it is not recommended to use any of them. You can use it according to lab and research requirements. Always calculate from the exact mg printed on your own vial. Click any peptide name and it'll fill in the calculator above for you automatically.
| Peptide | Common vial | BAC water | Shop |
|---|---|---|---|
| BPC‑157 | 5 mg | 2 ml | View product → |
| TB‑500 | 5 mg | 2 ml | View product → |
| CJC‑1295 | 2–5 mg | 2 ml | View product → |
| Ipamorelin | 5 mg | 2 ml | View product → |
| GHK‑Cu | 50 mg | 5 ml | View product → |
| BPC‑157 + TB‑500 Blend | 20 mg total | 3 ml | View product → |
| CJC‑1295 + Ipamorelin Blend | 10 mg total | 2 ml | View product → |
| Glow Blend (BPC‑157 + GHK‑Cu + TB‑500) | 70 mg | 3 ml | View product → |
| Semaglutide | 5 mg | 2 ml | Browse collection → |
| Tirzepatide | 10 mg | 2 ml | Browse collection → |
Prices, exact vial sizes and current stock live on each product page — the table above is a calculator reference only.
Frequently asked questions
How much bacteriostatic water should I add?
There's no single right amount of water to add. It depends on what you're trying to do. Less water makes it stronger. The total peptide in the vial doesn't change whether you add more or less water. Many researchers use 1–3 mL as a common range, but you can enter your own choice.
How do I convert mcg to mg?
1 mg = 1,000 mcg. To go from mg to mcg, multiply by 1,000. To go from mcg to mg, divide by 1,000. The peptide calculator handles this for you.
How long does a mixed vial last, and how should I store it?
This depends on the specific product, so no one answer fits everything. As a general pattern, mixed vials are often good for a few weeks in the fridge, away from light, but always check the instructions for your own product. Avoid letting it freeze, and avoid repeated warming and re-cooling.
Can I draw more than one dose from the same vial?
Yes, if it's mixed with bacteriostatic water, that's the main reason it's used instead of plain water. Use a clean needle each time, and wipe the vial top with an alcohol swab before each draw.
What does "reconstitution" mean for peptides?
It's the step of adding a liquid — almost always bacteriostatic water — to a freeze-dried (lyophilized) peptide powder so it dissolves into a solution you can measure and draw into a syringe.
What is bacteriostatic water, and why is it used?
It's sterile water with a small amount of benzyl alcohol added as a preservative. That preservative slows bacterial growth, which is why it's the standard choice for a vial that will be drawn from multiple times rather than used all at once.
Can I use sterile water or saline instead of bacteriostatic water?
Both will dissolve the powder, but neither contains a preservative, so a vial mixed with plain sterile water or saline is generally treated as single-use rather than stored for repeated draws. Always follow the diluent stated on your product's documentation.
How much bacteriostatic water should I add?
There's no single correct amount — it's a trade-off between concentration and how easy the resulting dose is to read on your syringe. Common volumes are 1–3 ml. Adding more water doesn't change how much peptide is in the vial, only how it's spread across volume and syringe units.
Why does adding more water change the units I draw?
The vial always contains the same total mg of peptide. More water spreads that amount across a larger volume, so each dose needs more units to deliver the same mcg. Less water concentrates it into fewer units — the total dose is unchanged either way.
How many units should I draw for my dose?
That depends on three numbers: your vial's mg, the water you added in ml, and your target dose. Enter all three above and the calculator converts them into the exact syringe unit mark automatically.
How do I convert between mcg and mg?
1 mg equals 1,000 mcg. A 5 mg vial contains 5,000 mcg. Use the mcg/mg toggle next to the dose field above to enter your target dose in whichever unit you prefer.
What size syringe should I use — 0.3 ml, 0.5 ml, or 1 ml?
All three read on the same scale, 100 units per 1 ml, so a given dose works out to the same number of units regardless of barrel size. A smaller barrel just spreads a small dose over more physical length, which can make fine doses easier to read accurately.
What if my calculated dose isn't a whole number of units?
Round to the nearest mark you can read reliably, or adjust your water volume slightly so the dose lands closer to a whole unit. If you're frequently between ticks, a smaller syringe or a different water ratio usually helps.
What if my required draw volume is larger than my syringe?
Add less bacteriostatic water so the solution is more concentrated, switch to a larger syringe, or lower the target dose. The calculator flags this automatically with a warning.
How long does a reconstituted peptide last?
Most reconstituted peptides are commonly cited as stable for roughly 2–4 weeks when refrigerated at 2–8°C and protected from light, though this varies by compound. Always check the specific storage guidance for the product you're using.
How many doses will one vial provide?
Divide the total mcg in the vial (mg × 1000) by your per-dose mcg amount. The calculator shows this as "Doses per Vial" once all four steps are filled in.
Are peptides the same as steroids?
No. Peptides are short chains of amino acids that act as signalling molecules — structurally and mechanistically distinct from anabolic steroids, which are steroid-hormone derivatives.
How do peptide hormones work, in basic terms?
Most peptides act by binding to specific receptors on a cell's surface, which triggers a signalling cascade inside the cell. This is part of why very small, mcg-level amounts can have a measurable effect.
What general handling precautions apply to research peptides?
Standard laboratory practice: work on a clean surface, swab vial stoppers with alcohol before puncturing, avoid introducing unnecessary air into a multi-dose vial, and dispose of needles in an approved sharps container. Follow your institution's or supplier's specific handling protocol.
Can copper peptides like GHK‑Cu be used topically as well as by injection?
GHK‑Cu is widely studied in both topical (skincare) and injectable research formats. The two use different concentrations and formulations, so a product intended for one route shouldn't be assumed interchangeable with the other.
Is this calculator medical advice?
No. This tool performs the reconstitution math for research and laboratory reference use only. It does not diagnose, treat, or recommend a dose for any condition — always follow your product's documentation and consult a qualified professional for anything intended for human or animal use.
Research use disclaimer
This calculator is provided for research, laboratory reference, and educational purposes only. The products discussed and sold on this site are not intended for human or animal consumption, diagnosis, treatment, cure, or prevention of any disease.
Always verify the exact mg content of your specific vial and consult your certificate of analysis before performing any calculation. Ultra Peptides is not responsible for how visitors choose to use this tool.
Explore our research peptides
Browse third-party tested peptides and bacteriostatic water in our shop.
Read the full peptide calculator guide
Choosing the Right Water Ratio for Your Dose
Read carefully. There is no single amount of bacteriostatic water (sterile, non-pyrogenic water containing 0.9% benzyl alcohol as a preservative) that is the right amount for every peptide. The amount of water researchers use affects how concentrated the final solution is and how easy it is to measure the desired amount. However, adding more or less the amount of water does not affect the volume of peptide in a vial.
Adding more bacteriostatic water makes the peptide solution more diluted(less concentrated). This means a small amount of peptide will take up more space in the syringe. For very small doses, this can make measurement easier because the dose covers more syringe markings and is therefore easier to read accurately.
And, adding less water creates a more concentrated solution. In this case, the same amount of peptide is contained in a smaller volume. This can be useful when you need to keep the amount drawn into the syringe small or when the intended dose is relatively large.
The important point is that adding more or less water does not change the total amount of peptide in the vial. It only changes the concentration and, as a result, the volume needed to measure a particular dose.
For example
Imagine a research vial containing 10 mg of peptide.
- If you add 2 mL of water, the concentration is 5 mg/mL. The peptide is more diluted, so you need a larger volume of solution to obtain a particular amount of peptide.
- If you add only 1 mL of water, the concentration is 10 mg/mL. The peptide is more concentrated, so you need a smaller volume of solution to obtain the same amount.
For example, if your research protocol requires 1 mg of peptide:
- At 5 mg/mL, 1 mg corresponds to 0.2 mL of solution.
- At 10 mg/mL, 1 mg corresponds to 0.1 mL of solution.
Note:You still have 10 mg of peptide in the vial in both cases. Adding more or less water only changes the concentration, which changes the volume of solution containing a particular amount of peptide.
This is why the water-to-peptide ratio matters in a peptide calculator. The calculator uses the amount of peptide and liquid to determine the concentration and the corresponding volume, rather than relying on guesswork.
Common reconstitution mistakes
Reconstituting a peptide requires care. Small mistakes can affect the concentration, measurement, or cleanliness of the solution.
- 1. Adding the water too forcefully:Do not direct a strong stream of water straight onto the powder. Forceful mixing can potentially damage some peptides. A gentler approach is to allow the liquid to run down the inside wall of the vial rather than hitting the powder (peptide) directly.
- 2. Shaking the vial:Avoid aggressively shaking a mixed peptide. Forceful shaking can affect the structure of some peptides. Instead, use gentle swirling or rolling movements to help the powder dissolve.
- 3. Guessing the amount instead of calculating it:One of the most common mistakes is trying to estimate the amount by simply looking at the syringe. The correct measurement depends on the amount of peptide, the amount of water added, and the resulting concentration. Even a small error when preparing the solution can lead to a significantly different dose and wrong results. Using the appropriate calculation is therefore much safer than relying on visual estimation.
- 4. Keeping the mixed solution in unsuitable conditions:Once a peptide has been reconstituted, its stability may be different from when it was stored as a dry powder. Leaving a mixed vial exposed to room temperature or light for long periods may reduce its stability. Storage requirements can vary by product, so always follow the manufacturer's or pharmacy's instructions for the specific peptide.
- 5. Reusing needles: Reusing needles can increase the risk of contamination and infection. If a research protocol recommends using separate equipment for drawing and administering a solution, follow that guidance.
Syringe and Needle Basics
Common insulin syringe barrel sizes include:
- 0.3 mL
- 0.5 mL
- 1 mL
These syringes can use the U-100 scale, where 100 units correspond to 1 mL.
Changing from one barrel size to another does not change the underlying volume represented by the U-100 scale. What changes is the physical size of the syringe and how closely the measurement markings are spaced.
For example, a smaller syringe may make it easier to see and measure very small volumes because its markings can be easier to read precisely.
Needle size is a separate issue from the mixing calculation. Needle characteristics such as length and gauge affect how the solution is handled or administered, but they do not change the concentration calculation itself.
Understanding the Basic Terms
Lyophilized
Lyophilized means the peptide has been freeze-dried into a powder. This process allows the product to be stored in a dry form before it is mixed with bacteriostatic water.
BAC Water
BAC water is short for bacteriostatic water. It is sterile water containing a bacteriostatic preservative and is used with certain products according to their specific instructions.
Concentration
Concentration describes how much peptide is contained in a specific amount of liquid.
It is commonly expressed as mcg/mL (micrograms per milliliter).
For example, if a solution has a higher concentration, more peptide is present in each milliliter. If it has a lower concentration, there is less peptide per milliliter.
Unit (U)
On a standard U-100 insulin syringe, 100 units correspond to 1 mL.
Therefore:
1 unit = 0.01 mL
The unit markings are simply another way of describing the volume in the syringe. They do not represent a fixed amount of peptide because the actual amount of peptide depends on the solution's concentration.
Titration
Titration means gradually adjusting a dose over time rather than immediately using a larger dose.
The Main Idea to Remember
The most important concept is simple:
The amount of water changes the concentration, not the total amount of peptide in the vial.
More water → more diluted solution → larger volume for the same amount of peptide
Less water → more concentrated solution → smaller volume for the same amount of peptide
Because concentration determines how much peptide is present in a given volume, accurate calculations are important. Do not rely on guessing or visual estimation when preparing or measuring a product.
This guide is educational and general in nature. It doesn't replace your product's own documentation or professional guidance for anything intended for human or animal use.