Users report transferring the liquid from 15 mg single-dose pens into sterile vials or directly into pen cartridges to allow smaller or split doses for those sensitive to side effects. Several describe using syringes to draw out the 0.5 ml contents, dealing with foam from the spring mechanism, and then loading multi-dose amounts into 5 ml syringes or cartridges for monthly use. Others note the lack of preservatives in US single-use pens increases contamination risk, though some still do it with basic sterile technique or by removing the internal cartridge entirely. A few mention that multi-dose pens available elsewhere contain preservatives and are designed for repeated use.
What this discussion establishesWhether adding bacteriostatic water makes repeated use acceptably safe, and whether cartridge removal is cleaner than syringe transfer
Still openHow long the transferred liquid remains stable or sterile beyond a few weeks when stored in the fridge
Nothing here is advice.
It might seem strange to consider, yet it's because someone gets bad reactions from the usual amount. That approach would let them divide it up or use only part of it. I'm wondering whether that's okay. Were these devices meant to hold the stuff for repeated applications?
I used to do this regularly when paying for the brand name. I would take the higher strength pens and empty them into a sterile vial so I could dose lower. There is a video showing how straightforward the process is.
It is definitely possible. The simplest way might be drawing it out with a syringe and needle then putting it straight into the 3 ml part of the pen because getting the vent needle in can be tricky otherwise. Lots of people already count clicks on the disposable pens they receive but when that is not an option this works for getting smaller doses.
I have some 15 mg ones that I cannot take all at once. I release the contents into a syringe and then move it into a sterile vial with no problems so far.
The autoinjectors sold in the USA are only single-use single-dose devices unlike the four-week versions sold in Canada the UK the EU and most other places.
The video works well. Just make sure the pen needle actually goes into the Luer-Lok syringe opening. I take my four pens each month and empty them all into a 5 ml Luer-Lok syringe because the spring tension creates a lot of foam. Each pen holds 0.5 ml but the foam makes a 3 ml syringe too small. After emptying all four I roll the 5 ml syringe gently for a few minutes to reduce the foam or just let it sit. Then I attach a 29 g Luer-Lok needle and load the full 2 ml into a pen cartridge so I can use new 31 g needles and choose any amount I want throughout the month.
Is insurance or your situation making you stick with pens when the name-brand vials would be simpler for this? The vials are cheaper and easier and let people adjust doses directly. These pens are not made for multiple uses and lack preservatives so it is not considered safe though many still reuse single vials anyway. To lower the risk I would put only one pen into each vial. What dose are you aiming for compared with the pen strength? Spacing out the injection days might be simpler. If you have any doubts just stop because people have spilled the liquid and lost it.
I began by emptying the pens into a sterile vial. It is worth watching more than one video because the one mentioned did not show careful sterile technique. At the very least wash your hands and work in a very clean area.
Information online indicates that the single-dose autoinjectors in the USA contain no preservatives while the multi-dose versions used elsewhere do contain them.
I would use the approach shown in the first video to split the pens. Another method needs a wrench but feels more sterile. I never had to try either because single-dose vials became available. I had a box of 7.5 mg autoinjectors that I kept delaying until I was already on 15 mg so I used two of them over two weeks to finish them.
It works fine because the cartridge inside is the same one used in the pen. Each pen leaves 0.5 ml that cannot be used otherwise. I used to cut the pen open in the middle with a dremel tool remove the cartridge and place it into a pen. Some people just draw the liquid out with a syringe instead. Removing the cartridge reduces contamination risk. Once the cartridge is out you can inject whatever amount you want with the pen.
What about adding some bac water to act as a preservative?
How exactly did you use the dremel on the pen? Are you saying the cartridge can go straight into another pen? Also what do you think about repeated use since these single-use pens have no preservative?
According to the FDA label what happens inside the cartridge depends mostly on how clean the preparation is even if only buffer and salt are added. I would not go past three or four weeks at one injection per week when using a pen. For longer periods I would make several single-use cartridges and keep them in the fridge or prepare several single-use syringes the same way. Hospitals store insulin in polypropylene syringes with sterile saline in the fridge for up to two months and after three months ninety percent of the activity remains with no contamination.
I do not know anything about single-use pens. Here Mounjaro is always sold as a multi-use pen.
I am not sure if multi-use pens are available for this medication in the US though there are claims they exist for the other brand mostly for cash-pay patients while insurance is steered toward the single-use pens. The multi-use version has preservatives so custom dosing is straightforward without extraction. From the original post it sounds like the single-use autoinjectors are the ones being discussed and those clearly have no preservatives according to the box and paperwork which makes repeated use more complicated so spacing out injection days seems safer.
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