How come using Insulin Injector Pens are not very common for SUBq oil shots?

[strixsir]

I have used the insulin pens after filling empty sterile 3ml cartridges with Test C,

If you are using a high Frequency pinning protocol, why not use pens?

Have used a 30G pen needle and it is really convenient to use .

for alternate day or daily pins, They literally take 10 seconds to pin 0.2 ml SubQ.

How come peptide community uses them a lot yet i rarely see mentions of it for Oils? Not even TRT folks mention it much.

 

[Barney67]

With 3mL cartridge volume and most T being 250mg/mL, having to fill a new cartridge every week or two if you aren’t doing TRT doses is a PITA. Also the stoppers are uncoated butyl rubber.

 

[strixsir]

With 3mL cartridge volume and most T being 250mg/mL, having to fill a new cartridge every week or two if you aren’t doing TRT doses is a PITA. Also the stoppers are uncoated butyl rubber.

as long as the stopper is grey, it will be fine, zero degradation, though not ideal for long-term contact for sure.

i have vials filled from last year, literally zero particles.

and i am talking specially for people do high frequency pins, the pen is worth the convenience it provides.

even more if one has stacked multiple compounds, just use multiple pens.

 

[Mariusdr]

I think some people do here, there was a thread on the pens themselves. Think for daily TRT it probably makes sense (if you would pin subq daily anyway. It is similar to daily peptides, which I think are more convenient in pens, it’s just smoother and also less slin pins to toss away

 

[Photon]

as long as the stopper is grey, it will be fine, zero degradation, though not ideal for long-term contact for sure.

i have vials filled from last year, literally zero particles.

and i am talking specially for people do high frequency pins, the pen is worth the convenience it provides.

even more if one has stacked multiple compounds, just use multiple pens.

Does it make a difference tho, if you poke that grey stopper daily?
I used to use the pens for hgh, then i got lazy to do it every week and now i just pin with an insulin pin.

I know @bananafeet seems to have successful with it.

Post in thread 'Refillable injector pen'

Jan 19, 2026

Look at the difference in the colour of a syringe plunger verses these cartridges. There is obviously a different material being used. The syringes are probably natural rubber or a composite. The grey is probably silicone or butyl rubber which is more resistant to solvents....

• bananafeet

• 

 

[powerdiesel]

I do 0.30 mL EOD in a v2 injector pen with a 29g .5" pen needle and love it. Incredibly quick and simple. Every ~3 weeks I have to reload a cartridge but that takes me less than 60 seconds. Just pull 3 mL out of vial, put a vent needle in the cartridge, and push the oil in.

I put my injector pen in a baby wipe warmer on low heat the night before my injection and it goes in as easily as a peptide through a 33gauge.

 

[Mfras]

Because slin pins are dirt cheap and I get to pick my needle based on injection site- 30g 5/8 for sub Q GH or rare peptide use, 29g 5/8 for shallow IM in the delts for daily or trt 2x/week, 25g 1” for glute or ventro for higher volume or site rotation.

I don’t do oils subQ and my pharma TestC is thick as hell and even draws crazy slow with the bottle on a mug warmer till it almost hurts to touch

 

[strixsir]

Does it make a difference tho, if you poke that grey stopper daily?
I used to use the pens for hgh, then i got lazy to do it every week and now i just pin with an insulin pin.

I know @bananafeet seems to have successful with it.

Post in thread 'Refillable injector pen'

Jan 19, 2026

Look at the difference in the colour of a syringe plunger verses these cartridges. There is obviously a different material being used. The syringes are probably natural rubber or a composite. The grey is probably silicone or butyl rubber which is more resistant to solvents....

• bananafeet

• 

They have butyl rubber with some coating, i am banking on the odds that they dont degrade for a year atleast

insulin vials are made for multiple dosages so i think its fine while the pen system itself acts as aseptic environment.

 

[strixsir]

Because slin pins are dirt cheap and I get to pick my needle based on injection site- 30g 5/8 for sub Q GH or rare peptide use, 29g 5/8 for shallow IM in the delts for daily or trt 2x/week, 25g 1” for glute or ventro for higher volume or site rotation.

I don’t do oils subQ and my pharma TestC is thick as hell and even draws crazy slow with the bottle on a mug warmer till it almost hurts to touch

even i has peanut oil carrier, its pretty thick/viscous compared to MCT,


Its winter here in india and yet its all the same with pen use, takes 10 seconds.

 

[Photon]

even i has peanut oil carrier, its pretty thick/viscous compared to MCT,


Its winter here in india and yet its all the same with pen use, takes 10 seconds.

Peanut


MCT


Not sure about EO but id stick to peanut.

 

[BigDadd7]

as long as the stopper is grey, it will be fine, zero degradation, though not ideal for long-term contact for sure.

i have vials filled from last year, literally zero particles.

and i am talking specially for people do high frequency pins, the pen is worth the convenience it provides.

even more if one has stacked multiple compounds, just use multiple pens.

Where did you come up with that? There are plenty of noncoated grey stoppers that dissolve from solvents.

 

[Lokey]

I use them them. 0.6ml of 300mg/ml Test U once a week, I fill a cartridge every 5 weeks.

Haven't seen any stopper degradation but I know that's a concern some have.

 

[strixsir]

Where did you come up with that? There are plenty of noncoated grey stoppers that dissolve from solvents.

fluororesin coated butyl rubber stoppers are the industry standard for sealing insulin vials.

i buy from alibaba china but the vendor is 15+ year old with history but i trust that i will have standardized vials.