How Many Doses Per Vial of Cagrilintide? (2026 Guide)

A standard 5mg lyophilised cagrilintide vial yields 10 doses at 0.5mg weekly maintenance or 5 doses at the 1mg threshold dose. But that assumes you reconstitute correctly and account for overfill. The gap between doing this right and wasting peptide comes down to three things most guides skip entirely: bacteriostatic water volume, injection technique that doesn't waste dead space in the syringe, and understanding that 'doses per vial' is a calculation, not a fixed number stamped on the label.

Our team works directly with researchers managing multi-week peptide protocols. The reconstitution errors we see aren't contamination failures. They're simple dose-calculation mistakes that leave researchers either scrambling for more vials mid-study or discarding functional peptide because they miscounted from the start.

How many doses are in a 5mg vial of cagrilintide?

A 5mg cagrilintide vial contains 10 doses at 0.5mg weekly maintenance or 5 doses at 1mg weekly, assuming standard 2ml bacteriostatic water reconstitution. Dose count depends on prescribed weekly dose and accurate volumetric measurement. The vial contains a fixed peptide mass (5mg), which you divide by your target dose per injection to calculate usable doses.

The Featured Snippet answers what's in the vial. This section covers what happens when you reconstitute it. And why two researchers using identical 5mg vials can end up with different dose counts. Cagrilintide is dosed weekly via subcutaneous injection, with clinical escalation protocols starting at 0.3mg and titrating to maintenance doses between 0.5mg and 2.4mg depending on endpoint targets. The actual doses per vial shift based on where you land in that range. A researcher running 0.3mg for 16 weeks extracts 16 doses from one vial; another running 1.2mg extracts only 4 doses from the same vial. This article covers exact reconstitution math, how to calculate your specific dose count, and what preparation mistakes negate dose accuracy entirely.

Cagrilintide Vial Specifications and Peptide Mass

Cagrilintide is supplied as lyophilised powder in sealed glass vials containing 5mg or 10mg of peptide by weight. Not by volume. The powder itself occupies minimal physical space; what determines 'how many doses vial cagrilintide' delivers is the reconstitution volume you add and the dose prescribed per injection. Standard research protocols use 5mg vials reconstituted with 2ml bacteriostatic water, yielding a concentration of 2.5mg/ml. At that concentration, a 0.5mg dose requires 0.2ml per injection. Meaning one 5mg vial contains 10 doses at 0.5mg weekly.

The calculation changes with dose escalation. At 1mg weekly, that same 2ml reconstitution requires 0.4ml per injection. Cutting usable doses to 5 per vial. At 2mg weekly, you're extracting 1ml per injection, so one 5mg vial yields only 2.5 doses. This is why researchers titrating from 0.3mg to 1.2mg over 12 weeks cannot order a single vial and assume it covers the full protocol. Dose count per vial drops as weekly dose increases. Our experience with multi-phase research designs shows that miscalculating vial needs at the dose-escalation stage is the single most common procurement error that disrupts study timelines.

Reconstitution Protocol and Concentration Calculation

Reconstitution is where dose count becomes fixed. Add 2ml bacteriostatic water to a 5mg vial and you create a 2.5mg/ml solution. Every 0.1ml contains 0.25mg of cagrilintide. Add 1ml instead and you double the concentration to 5mg/ml, which halves the injection volume per dose but doesn't change total doses available (you're still starting with 5mg of peptide). The concentration you choose determines syringe convenience, not dose availability.

Here's the protocol: remove the flip-top cap from the lyophilised vial and swab the rubber stopper with 70% isopropyl alcohol. Draw 2ml bacteriostatic water (0.9% benzyl alcohol) into a sterile 3ml syringe fitted with an 18-gauge needle. Inject the water slowly down the inside wall of the vial. Not directly onto the powder, which can denature the peptide structure. Swirl gently until fully dissolved; do not shake. The resulting solution is stable for 28 days when refrigerated at 2–8°C. Cagrilintide's half-life of approximately 7 days makes weekly dosing viable, but the reconstituted solution degrades faster than the lyophilised form. Any temperature excursion above 8°C accelerates peptide breakdown that neither visual inspection nor home testing can detect.

Dose-per-Vial Calculation Across Weekly Dose Ranges

This table assumes 2ml reconstitution volume and 100% usable peptide mass. In practice, researchers lose 0.05–0.1ml in syringe dead space per draw, which compounds across multiple doses. A 5mg vial reconstituted to 10 doses at 0.5mg each may only yield 9 usable doses once dead space is accounted for. Order one extra vial for protocols spanning 8+ weeks to avoid shortfalls.

What If: Cagrilintide Dosing Scenarios

What If I Need to Switch Dose Mid-Protocol — Do I Need a New Vial?

No, if you're moving from 0.5mg to 1mg weekly and your current vial still contains 2ml of reconstituted solution. Simply draw a larger volume per injection. 0.4ml instead of 0.2ml. From the same vial. You'll exhaust the vial faster (5 remaining doses instead of 10), but the peptide concentration doesn't change. Recalculate total vial needs for the remainder of your protocol and order accordingly.

What If I Accidentally Reconstituted with 1ml Instead of 2ml?

Your concentration is now 5mg/ml instead of 2.5mg/ml. Double the standard. A 0.5mg dose now requires 0.1ml instead of 0.2ml. This doesn't reduce efficacy, but it increases injection-volume precision requirements. Insulin syringes marked in 0.01ml increments become essential. The total doses per vial remain unchanged (you still have 5mg of peptide), but measurement error risk doubles because you're working with smaller volumes.

What If My Vial Contains Visible Particulates After Reconstitution?

Discard the vial. Particulates indicate incomplete dissolution, contamination, or protein aggregation. None of which resolve with additional swirling. Cagrilintide should reconstitute to a clear, colourless solution within 2–3 minutes of gentle swirling. Cloudiness, floating particles, or sediment at the vial bottom all signal unusable product. This occurs in fewer than 2% of properly stored vials but approaches 15–20% in vials exposed to temperature excursions during shipping.

The Clinical Truth About Cagrilintide Dose Variability

Here's the honest answer: there is no universal 'doses per vial'. The number depends entirely on your prescribed weekly dose and whether you account for practical losses like syringe dead space. The 5mg vial label doesn't tell you how many injections you'll get because it can't. That's a calculation you make after reconstitution based on target dose. Researchers who assume 'one vial = X weeks' without doing the math consistently run short mid-protocol or over-order and waste peptide that expires before use.

The second truth: dead space matters more than most guides admit. Low dead space syringes (0.01–0.02ml residual) versus standard insulin syringes (0.05–0.08ml residual) create a 10–15% difference in usable doses across a 10-week protocol. That's the difference between a 5mg vial lasting 9 weeks versus 10 weeks at 0.5mg weekly. Real Peptides supplies research-grade cagrilintide with batch-specific certificates of analysis. Every vial ships with documented peptide purity above 98%, which eliminates one variable (peptide mass accuracy) from your dose calculations.

Storage, Stability, and Dose Preservation

Unreconstituted cagrilintide vials must be stored at −20°C and remain stable for 24–36 months under these conditions. Once reconstituted with bacteriostatic water, refrigerate at 2–8°C and use within 28 days. This is the stability window confirmed by HPLC testing showing less than 5% peptide degradation. The 28-day limit is not arbitrary: benzyl alcohol in bacteriostatic water preserves sterility but does not prevent peptide oxidation, which accelerates after one month even under refrigeration.

Temperature excursions are the silent dose killer. A vial left at room temperature (20–25°C) for 48 hours loses approximately 15–20% potency. Meaning your calculated 0.5mg dose delivers only 0.4–0.425mg. This degradation is cumulative and irreversible; re-refrigerating the vial does not restore potency. For researchers managing multi-week studies, we've found that purpose-built peptide coolers (like FRIO wallets using evaporative cooling) maintain 2–8°C for 36–48 hours without ice or electricity. Essential for fieldwork or shipping between lab sites.

Cagrilintide's mechanism as an amylin analogue. Binding CALCR (calcitonin receptor) and RAMP receptors to slow gastric emptying and reduce food intake. Remains intact only if the peptide's tertiary structure is preserved. Heat, agitation, and pH shifts all disrupt disulphide bonds that hold the active conformation together. You can't visually confirm potency loss; a denatured solution looks identical to a functional one.

The practical implication: if you're running a 12-week protocol at 0.5mg weekly, order three 5mg vials. Not two. The third vial covers measurement error, dead space losses, and the reality that not every injection draws exactly 0.2ml. Running out of peptide at week 10 of a 12-week endpoint study isn't a minor inconvenience. It's a protocol failure that invalidates your dataset. Conservative ordering based on accurate dose-per-vial math is the difference between completing a study and restarting it.

Researchers working with advanced peptide compounds like Survodutide or Mazdutide face identical reconstitution and dose-calculation requirements. The principles here apply across lyophilised peptide classes. Accurate dose counting isn't peptide-specific expertise; it's fundamental laboratory math that determines whether your protocol succeeds or stalls mid-execution.

You're not ordering 'a vial of cagrilintide'. You're ordering a fixed peptide mass that you'll divide into a calculated number of doses. Get the math right before you place the order, not after the vial arrives and you realize you're three doses short of completing the protocol.