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How-to · reconstitution
Put 1 mL of bacteriostatic water into the 5 mg Cagrilintide vial. That makes 5.00 mg/mL. A 2.4 mg dose is then 48.0 units on a U-100 syringe.
That volume is the one that lands the draw on a syringe line, so the reading can be checked by eye. More water makes a weaker mix and a bigger draw. Less water makes a stronger mix and a smaller one. The amount of Cagrilintide in the glass never changes. Only the number of marks it takes does.
Cagrilintide is a weekly shot in weight-loss studies. It copies amylin, a natural signal that helps you feel full after eating.
| Water added | Concentration | Per U-100 unit | Example: 2.4 mg = |
|---|---|---|---|
| 1 mL | 5.00 mg/mL | 50 mcg | 48.0 units |
| 2 mL | 2.50 mg/mL | 25 mcg | 96.0 units |
Straight arithmetic: concentration = 5 mg ÷ water, and 1 U-100 unit = 0.01 mL. The example column shows the math at 2.4 mg; it is not a dose recommendation.
Which volume to use is a practical choice rather than a dose. Pick the one that puts your draw somewhere you can actually read it on the syringe. The flags in the last column mark where that fails. “Hard to measure” means the draw is too small to judge by eye. “Won’t fit” means it is bigger than one U-100 syringe holds.
The table above uses one worked example. These are the published quantities, converted into marks on a U-100 barrel at each water volume for a 5 mg vial. Where a quantity was never studied by injection, the row says so.
0.3–4.5 mg once weekly, under the skin. (phase 2 dose-finding arms, reached by 4-week escalation steps).
| Water added | Concentration | Draw, low to high |
|---|---|---|
| 1 mL | 5.00 mg/mL | 6.0 to 90.0 units |
| 2 mL | 2.50 mg/mL | 12.0 to 180.0 unitswon’t fit |
Human trialLau DCW et al. Once-weekly cagrilintide for weight management: dose-finding phase 2 trial. Lancet 2021;398:2160-72 (PMID 34798060) · retrieved 2026-08-17
The worked amount uses nearly half the vial, so it empties in two draws. With the larger water amount, one draw nearly fills a U-100 syringe.
There is no rationing to plan and no schedule to fit a vial this size into. Mix it, draw twice, and it is gone.
The vial is used in very few draws, so long-term storage is less likely to matter. Even so, no published source gives a storage window for the mixed vial.
Two draws also gives whatever uncertainty attaches to storing a mixed research peptide the least possible time to matter. It is the one advantage a vial this small has.
At the larger listed volume the draw covers almost the whole syringe. It fits, but there is no headroom, and the upper end of the studied range would not fit at all.
That is the practical argument for the smaller volume on this page, and it is the reverse of the advice most of these guides give.
The figures here look alarming beside a semaglutide page, and the comparison is meaningless. This compound copies a pancreatic hormone rather than a gut one, and its studied amounts sit higher in milligrams.
Milligrams compared across compounds tell you nothing. Only the draw, on your vial, at your water volume, does.
The table shows the offered water volumes. The calculator does the same arithmetic for any volume and any syringe, and shows its working line by line.
Open the Cagrilintide calculator →The arithmetic on this page is only half the question. These are the pages that carry the other half.