Cartridges and pen needles are small components, but a mismatch with the pen stops a program in its tracks. Here's how to specify them correctly.
3 mL cartridges
- Glass cartridges, commonly Type I glass, with a plunger stopper and crimped cap with septum.
- Sterile, ready-to-fill options save processing steps.
- Confirm the cartridge matches the pen's dimensions and plunger travel.
Pen needles
- Gauges commonly range from 29 G to 32 G; higher gauge numbers are thinner.
- Lengths commonly range from 4 mm to 8 mm. Shorter needles are widely used for subcutaneous injection; providers decide what's appropriate.
- Most pen needles use a universal thread that fits many pens. Confirm compatibility.
- Safety pen needles with shields are available for clinic use.
Packaging and sterility
Pen needles come individually sealed and sterile. Check expiration dates when ordering by the case, and rotate stock.
Estimating quantities
Estimate quantities from your program: cartridges per patient per month (often one per pen fill) and pen needles per dose. Pen needles are single-use, so needle volume is typically many times cartridge volume. Add a buffer for wasted needles and priming.
Patient disposal
Patients using pens need a way to dispose of used needles. Many programs include a small sharps container in the patient kit, along with written disposal instructions.
Questions to ask your supplier
- Is the cartridge compatible with the pen's dimensions and plunger travel?
- Are the needles universal-thread?
- Are safety pen needles available for in-clinic use?
- What's the shelf life on sterile components?
Ordering tips
Order pens, cartridges and needles together, and keep a ratio based on doses per patient per month. Pen needles are single-use, so needle volume is usually the highest.
Frequently asked questions
Do pen needles fit all pens?
Many use a universal thread, but not all pens accept every needle. We confirm compatibility for the pens you use.
What gauge and length should we stock?
That's a clinical decision for your providers. We stock the common range from 29 G to 32 G and 4 mm to 8 mm.
Can we set up a standing order for needles?
Yes. We'll size it to your monthly dose volume.
Should patient kits include a sharps container?
Many programs include one with disposal instructions, which helps patients dispose of needles safely.
Ready to price cartridges and pen needles?
Send us what you need and we'll reply with one quote, usually within a business day.
This guide is general product and purchasing information for licensed healthcare businesses. It isn't medical, legal or regulatory advice. Follow your medical director's protocols and the manufacturer's instructions.