Click-to-dose vs unit-to-dose: how the math differs
Insulin pens dose in units. Aevum cartridges dose in clicks. Both are valid; they map differently to the underlying milligrams. Here is how the conversion works, and why the cartridge format makes the math harder to get wrong.
If you are coming to Aevum cartridges from a background in diabetic insulin pens — or from the wave of GLP-1 prescriptions that brought Ozempic, Wegovy, Mounjaro and Zepbound into the mainstream — you are used to dosing in units. A unit of insulin is a fixed mass of insulin. A unit of semaglutide is a fixed mass of semaglutide. The pen dials in whole units, and the dose corresponds directly to the volume the pen displaces.
Aevum cartridges dose in clicks, not units. The math is similar but the units are different, and the difference matters when you are translating a research protocol from a published paper into a click count on the pen dial.
What a click is
Every Aevum cartridge delivers exactly 60 clicks from full to empty. Each click corresponds to a fixed volume of solution displaced from the cartridge through the needle — 0.05 mL per click, consistent across the entire catalog. What changes between cartridges is the concentration of the peptide in solution, which determines how many milligrams of peptide each 0.05 mL volume contains.
The formula is straightforward: cartridge total milligrams divided by 60 equals milligrams per click. A 500 mg NAD+ cartridge delivers 8.33 mg per click. A 24 mg Retatrutide cartridge delivers 0.4 mg per click. A 20 mg BPC-157 cartridge delivers 333 mcg per click. Every cartridge label prints both the total mass and the per-click mass so you do not have to calculate.
Why clicks instead of units
The unit system works well for compounds where the dosing range across users is narrow and the manufacturer has chosen a single concentration for the product line. Insulin is dosed in units because every Type 1 diabetic in the world buys insulin at the same concentration (U-100), and the unit of insulin is a calibrated mass that does not change between pens.
Research peptides do not work that way. NAD+ protocols cited in published research range from 50 mg weekly to 500 mg weekly across different research questions. GLP-1 research protocols span an even wider range. Pinning a single "unit" mass to an entire catalog of compounds with different dose ranges would mean either making the unit small enough to be useful for the lowest dose (in which case the highest dose requires hundreds of clicks) or large enough for the highest dose (in which case the lowest dose is a quarter of a click, which the pen cannot deliver).
Clicks solve the range problem by tying the volume per click to the cartridge geometry rather than to the compound. The pen always delivers 0.05 mL per click. What you do with that volume depends on which cartridge is loaded.
How the math gets harder to get wrong
The traditional vial-and-syringe workflow requires the researcher to do four calculations: total peptide mass divided by reconstitution volume gives concentration; target dose divided by concentration gives draw volume; draw volume read off the syringe barrel in milliliters; syringe marks interpreted to the nearest 0.01 mL. A decimal error at any step changes the dose by a factor of ten.
The cartridge workflow eliminates three of those steps. The total mass is fixed at filling, the volume is fixed at 0.05 mL per click, and the dose is read off the pen dial as a whole number. The only translation you do is between the target milligram dose in your research protocol and the corresponding click count — and the per-click mass is printed on the cartridge label so you can verify your conversion against the source.
Researchers running multiple cartridges concurrently — stacks, in the catalog vocabulary — get an additional benefit: every cartridge in the stack uses the same per-click volume, so the cognitive load of switching between compounds is the click count, not the mathematics. The researcher who runs NAD+ on Monday morning and Retatrutide on Tuesday evening dials a different click count, not a different volume. The pen does not know which compound is loaded; it just displaces 0.05 mL per click.
This is the entire payoff of the format. The chemistry is the same chemistry that ships in vials. What changes is how much of the user's attention the system requires to execute correctly. Less attention required means fewer errors in execution, which means the research the compound is being used for is what gets evaluated — not the researcher's syringe-barrel reading skills.