Home > Guides > Cartridge compatibility
Cartridge compatibility: what fits a ShotLog pen
Every ShotLog pen is built around the standard 3 mL glass pen cartridge. If a cartridge is that format it fits; if it is anything else it does not. Below: which cartridges fit which pen, what the standard cartridge looks like so you can recognise one, and what will not fit no matter how it is described.
Which cartridges fit which pen
Our 3 mL glass cartridgefits every pen we sell, the Auto Pen included, and is the one we test with. All four pens take the standard 3 mL cartridge with a long stopper, and the long stopper is the only kind we sell. Other makers' 3 mL cartridges in the same standard format also fit, but we can only vouch for the ones we sell.
| Pen | Our 3 mL cartridge | Other makers' 3 mL cartridges |
|---|---|---|
| Reusable Peptide Pen V2, Original Style | Yes | Yes, if it is the standard 3 mL format with a long stopper |
| Reusable Peptide Pen V2, New Style | Yes | Yes, if it is the standard 3 mL format with a long stopper |
| 510(k) Reusable 80 Unit Pen | Yes | Yes, if it is the standard 3 mL format with a long stopper |
| Auto Pen for 3 mL Cartridges | Yes | Yes, if it is the standard 3 mL format with a long stopper |
What a standard 3 mL cartridge looks like
A clear glass barrel, closed at both ends. At the bottom is a rubber plunger that the pen's piston pushes up. At the top is a crimped aluminum cap with a rubber septum in the middle; the pen needle screws onto the holder and its short inner end pierces that septum. The barrel holds 3 mL, which is 300 units on a U-100 scale.
Ours are USP Type 1 borosilicate glass, EO-sterilized by the maker and then steam-sterilized in a self-sealing pouch whose indicator turns from blue to black.
Our product page does not list the barrel's dimensions, so we do not print them here. If you need to check a cartridge against a holder, the test is simple: it drops in, the holder seats fully (it screws down on the Original Style, 510(k) and Auto pens, and pushes on and twists to lock on the New Style), and the septum sits flush at the top, where the needle goes on.
What does not fit
- Cartridges in other sizes. A cartridge that holds a different volume is a different length. The holders on our pens are made for the 3 mL length.
- Vials. A vial is a bottle with a stopper. It is not a cartridge. Liquid moves from a vial into a cartridge with a transfer syringe and a vent needle; the fill guide covers that.
- Refilled cartridges. A used cartridge is single use. It was not made to be emptied, cleaned and filled again, and a refilled one is the most common source of a stuck or leaking pen.
Check before you buy
- It is a 3 mL (300 unit) glass pen cartridge.
- It has a rubber plunger at the bottom and a crimped cap with a septum at the top.
- It has a long stopper. Every ShotLog pen is made for the long stopper, and it is the only kind we sell.
- The maker calls it a standard 3 mL pen cartridge.
- It is sold sealed and sterile, and you will use it once.
Choosing between the pens? See the pen comparison. Loading and filling are in the guides.
For research use only. Not for human or animal therapeutic, clinical, or diagnostic use. Not FDA-approved.
