Dream Pen: Ideal Features for a Peptide Injector with No Limits

It would help to know exactly how much is left in the cartridge. Some pens have lines on the holder but I cannot tell what they represent and instructions are often missing anyway. Priming is another annoyance because air can remain even after I think I have cleared it. Engineering around that would be useful. I also prefer not to leave a needle attached between doses so shorter overall pens would be better, though length is limited by the cartridge and plunger. Cartridge holders that screw in feel more secure to me.

Good luck with the project and finishing your degree.

The original auto-injector model would be ideal if it included a spring cap to cover the needle like the later version does.

I like that same auto-injector but wish it had a mode where pressing the button once lets it deliver without holding it down. These pens should also give an audible click or similar signal when the dose finishes so I know how long to leave the needle in. Adding a small battery and linking to an app for tracking doses and other details would be great.

Connecting two vials inside one pen so they both feed the same needle would let users mix compounds from separate vials with one device and one needle. You could load two different substances, set separate doses on two dials, inject once, and deliver both by pushing the plungers in sequence. A non-traditional shape might work if it still feels like a pen but supports dual loading, and a digital display would be a bonus.

A cartridge that empties completely would stop waste or the need to use a separate needle to recover the last bit. One-handed operation would also help reach awkward spots like the back of the hips.

I agree that knowing what remains inside matters and that recovering the final amount without waste is useful. Even though cost is low I still dislike discarding it. I avoid longer insulin needles and stick with shorter pen needles because I am still sensitive to them. The reduced pain makes it worth it. Congratulations on nearing the end of your degree.

If you could also create a pen needle that is much finer than current 34-gauge versions, works well, and does not break easily, that would be a major win.

I will not even list the fantasy features I would like such as self-purging or set-and-forget dosing. Among pens that already exist I would pick certain colors and models but the cost keeps me from buying multiples.

I would like to try a needle-free high-pressure injector that simply presses against the skin and delivers in seconds. Commercial versions still make loading awkward so my ideal version would let you click a vial in place, dial the volume, and fire.

Since I've only tried a few of those insulin-style pens my suggestions might not be that relevant. Still I'd want a reusable version that's as smooth as the ones I used, that displays the remaining volume in the cartridge, and that includes an insulated sleeve to keep things cool during travel in warm weather. Doesn't seem like too much to ask for a fair price.