Home › Guides › Pens vs Syringes: Supplies Each Needs
Pens vs Syringes: Supplies Each Needs
New to injecting at home with a pen? It needs remarkably little. The three things to buy, and what a vial needs instead.
Last reviewed · written by PepPrep · not medical advice
If what you have is a pre-filled injection pen — the kind a pharmacy or clinic hands over ready to use, often for a weekly injection — you need an almost entirely different shopping list from someone working with a vial. Quite a lot of what's written online assumes the vial route without saying so, which is why people end up buying mixing kit they'll never open.
If you're new to injecting at home, the honest short answer is that a pen needs remarkably little: the right needles, something to clean with, and somewhere safe to put the used ones. Everything else on this page is optional.
| Pen | Vial and syringe | |
|---|---|---|
| The consumable | Screw-on pen needles (32G, 4 mm is common) | Insulin syringes with the needle built in |
| Mixing kit | None — it arrives ready | Bac water, luer-lock syringe, blunt fill needle |
| Measuring | Dial on the pen | Read the units on the barrel yourself |
| Also needed | Alcohol pads and a sharps container (UK: sharps bin) — both routes, no exceptions | |
| Travel | Insulated pen case | Insulated case with room for vials |
Practical differences. A pen is faster and harder to misread, because the dose is dialled rather than drawn. A vial gives you finer control and usually costs less per unit, but there are more steps and more places to be careless. Neither is "better" — they're different products, and which you have isn't usually your choice.
The one thing people forget: pen needles are single-use too. Leaving one screwed on between uses lets air and contamination into the cartridge, and it blunts exactly like any other needle.
The three things every pen user needs, and nothing more to start with:
- Pen needles that fit yours. They're near-universal, but check the listing says it fits your pen. 32G, 4 mm is the common everyday choice.
- Alcohol prep pads. For the pen's rubber tip and for skin. Cheap, and you'll use a lot.
- A sharps container. Not a bottle, not the bin. See choosing a sharps container — and how to dispose of a full one.
Then, when you need them: an insulated pen case if the pen has to stay cold while you travel, a fridge thermometer if you want to know your fridge is genuinely in range, and anything from making injections hurt less if the needle is the part you dread.
Our Kit Builder has a "Using a pen" option that produces exactly this list, without the vial gear.
Supplies mentioned: Pen needles & syringes · Sterile Prep · Travel