Tools
Peptide reconstitution calculator
Handles the arithmetic, not the protocol. Every value below is one you entered — enter what is in your vial, how much water you added, and the dose you want, and the syringe shows you what to draw.
Enter what is in your vial, how much water you added, and the dose you want. The syringe above will show you what to draw.
BioAlmanac performs arithmetic on values you enter. It does not recommend doses, schedules or compounds, and nothing here is medical advice. Confirm every calculation against your vial and syringe before drawing, and speak with a licensed healthcare provider.
Blends
One vial, several compounds
You cannot dose the parts of a blend separately — one draw delivers all of them in the ratio the vial was filled at. Dose by whichever compound you are targeting and see what the same draw gives you of the rest.
One draw of 0.025 mL delivers all of the following.
| Compound | In the vial | Per draw |
|---|---|---|
| GHK-Cu | 50 mg | 250 mcg |
| BPC-157 | 10 mg | 50 mcg |
| TB-500 | 10 mg | 50 mcg |
Check2.5 units falls between the printed lines on a 1 mL U-100 syringe. Every compound in the blend shifts together, so rounding to the nearest line changes all of them.
CheckThe compounds in this vial are present in very different amounts, so one dose delivers very different quantities of each.
BioAlmanac performs arithmetic on values you enter. It does not recommend doses, schedules or compounds, and nothing here is medical advice. Confirm every calculation against your vial and syringe before drawing, and speak with a licensed healthcare provider.
Keep going
What next
- Find your compoundEvery profile carries the doses sources report, and a button that fills this calculator in from them.
- How to mix itThe physical steps, in order, and the mistakes that ruin a vial.
- Keep a scheduleTurn a dose into a protocol and log what you actually take. Free, and private by default.
- What things costPer-milligram prices read from vendor sites, so different vial sizes can be compared.
- Check a combinationWhat our profiles record about each pair in a stack, including the pairs where nothing is recorded.
- Units, IU, and the restA unit is not a fixed volume. Several entries exist because misreading the term is what causes the errors.
How the arithmetic works
Concentration
vial mg ÷ water mL
A 5 mg vial mixed with 2 mL of bacteriostatic water gives 2.5 mg per mL.
Units to draw
(dose ÷ concentration) × marks per mL
A 250 mcg dose is 0.1 mL of that solution, which is 10 units on a U-100 syringe and 4 units on a U-40.
A worked example: a 5 mg vial at 250 mcg
Take a 5 mg vial of lyophilised powder and 2 mL of bacteriostatic water. Adding all 2 mL to the vial puts 5 milligrams into 2 millilitres, so the concentration is 5 ÷ 2 = 2.5 mg/mL. That figure is the whole basis of everything after it: the powder does not change, but a different volume of water would give a different concentration and therefore a different number of units for the same dose.
Now say the dose you are working to is 250 mcg. Milligrams and micrograms have to meet first — 250 mcg is 0.25 mg. Dividing the dose by the concentration gives the volume to draw: 0.25 ÷ 2.5 = 0.1 mL. That is the answer in millilitres, and it is the same answer whatever syringe you own.
Units are where the syringe starts to matter, because a unit is a mark on a barrel rather than a fixed volume. A U-100 syringe is marked 100 times per millilitre, so 0.1 mL × 100 = 10 units. A U-40 syringe is marked 40 times per millilitre, so the identical draw is 0.1 mL × 40 = 4 units. Ten units and four units are the same quantity of peptide, which is why a number of units means nothing until the barrel it belongs to is named.
One more figure falls out of the same arithmetic. A 5 mg vial dosed at 0.25 mg holds 5 ÷ 0.25 = 20 doses, and at 0.1 mL each those 20 draws account for the full 2 mL that went in. In practice a vial yields slightly fewer than the arithmetic promises, because every transfer leaves a little behind in the needle and the hub.
Change any one input and the chain re-runs from the top. Mixing the same 5 mg vial with 1 mL instead of 2 gives 5 mg/mL, which puts the same 250 mcg dose at 0.05 mL — 5 units on a U-100 barrel instead of 10. Neither is more correct. The more dilute mixture simply spreads the dose over more marks, which is easier to read.
Questions
- How do I work out how many units to draw?
- Divide the milligrams in the vial by the millilitres of bacteriostatic water you added — that is your concentration in mg per mL. Divide your dose by that concentration to get the volume in millilitres, then multiply by the marks per millilitre on your syringe: 100 for a U-100 syringe, 40 for a U-40. The calculator does all three steps and draws the result on the barrel.
- What is the difference between units and millilitres?
- A unit is a mark on a barrel, not a fixed volume. On a U-100 syringe one unit is 0.01 mL; on a U-40 syringe the same mark is 0.025 mL. That is why this calculator always asks which syringe you are holding, and why it never shows a number of units without naming the barrel it belongs to.
- My dose lands between two marks. What should I do?
- A dose between marks cannot be drawn accurately. The calculator tells you which water volume would put the same dose on a printed line instead — you can reconstitute a fresh vial at that volume, or use a syringe with a finer scale.
- Does BioAlmanac tell me what dose to take?
- No. Every value in the calculator is one you entered, and we do not recommend doses, schedules or compounds. Dose ranges shown on compound profiles are cited descriptions of published literature or community practice, presented as information rather than guidance.
- How do I calculate a blend?
- Use the blend calculator below. Enter each compound in the vial with its amount, then dose by whichever one you are targeting. One draw delivers every compound in the ratio the vial was filled at, so the table shows what that same draw gives you of each — which is often not an even split.
- Is this a stock solution or a dilution calculator?
- Both, because they are the same arithmetic. Reconstituting turns a dry vial into a solution of known strength; diluting takes that solution and makes it weaker; a stock solution is simply the one mixed first. Under any of those names the question is how many milligrams sit in each millilitre, and how much of that to draw for the dose you want.
- How much bacteriostatic water should I add to a peptide vial?
- That is a choice you make, not a property of the vial. The same 5 mg of peptide can be mixed with 1 mL or with 3 mL and still deliver the same dose — what changes is the concentration, and with it the number of marks that dose occupies on the barrel. More water spreads a small dose across more marks, which is easier to draw accurately. Less water leaves a more concentrated solution and a smaller volume to store. Enter whichever volume you are using and the calculator shows the units for it, and tells you if the dose lands between two marks.
- Is there a reconstitution chart for my vial?
- Yes. Every compound sold in standard vial sizes has a page per size showing the concentration at each common water volume and what each dose our sources report draws to in units. They are linked from each compound profile, and they run the same arithmetic as this calculator, so the two cannot disagree.
- How do I split a vial into aliquots?
- Work out the concentration first, then decide how many milligrams each aliquot should hold and divide. The calculator gives you the concentration and the doses per vial, which is what that division needs. Worth knowing that every transfer leaves a little behind in the needle and the hub, so a vial rarely yields quite the number of full doses the arithmetic promises.
- Can I use this with an insulin pen?
- Not directly, and the difference matters. A pen is dialled in units of insulin, which are defined against insulin's own concentration, so a pen unit and a syringe unit are not the same amount of liquid. This calculator draws a barrel with printed marks. With a pen, the number that matters is the volume it delivers per click, which the pen's own documentation states.
- How many milligrams are in my vial?
- Whatever the label says, and it is worth checking rather than assuming. Vials of the same compound are commonly sold at 2, 5, 10, 15, 20 and 30 mg, and a listing quoting a total across several vials is easy to misread as one. This calculator takes the milligrams in a single vial. To compare what those sizes cost, the price index normalises everything to a cost per milligram.
Found something wrong? Tell us — we publish corrections.