Difficulties injecting, high resistance plunger

[mattgray]

I have been using the 1ml luer-lok BD syringe.
It feels very sturdy and high quality but when it comes to the plunger, it is very difficult to move.

Even fresh out of the package, with no liquids inside and no needle attached, the plunger moves with high resistance.

After sucking up my test oil, the plunger get’s even more stuck. Which becomes especially bad when injecting. I have to give the plunger my all, pressing as hard as I possibly can with just my fingers and even then, the plunger moves in short bursts about every second, if at all.

It makes the injection take a very long time, even for small volumes and I can imagine all the shaking and fiddling increases scar tissue/ damage to the muscle.

And it is most definitely not the needle gauge, because even after removing the needle, the plunger still moves barely/ very difficult. I need to press VERY hard to move the plunger, even though there is no needle attached.

Same goes by the way for sucking up oil out of the vial, although I feel once the oil enters the syringe, the problems become worse.

I read online a possible cause could be that the oil causes the rubber plunger to swell, increasing resistance.

Anyone else experienced this and any tips?

 

[oldgrey]

If they are ACTUAL BD brand and this is happening that is odd and you should contact the company (seriously) and they will probably replace them for you as it could be a bad batch.. I have some cheap flinmed from china that are poorly crafted - where the black inner part of the plunger (which is pointed) tat makes contact with the oil will shift slightly crooked which creates more friction leading to a difficult press. maybe something similar is happening?

 

[PiscesMoon]

Hi @mattgray Some questions that may help us to advise on your situation..

What is the gauge and length for the syringe needles you have been using?

What is the carrier oil type(s) you are working with?

For any oils, have you tried warming the vial before drawing up the dose & injecting?

 

[BabaJagga]

hey, i had same with these BD and TNE, something solvent related probably.

With regular test c in ussuall concentration i had no issues but with TNE, 23G needle, i had trouble even drawing the oil, heated.

i couldnt push everything in, 0,3ml was stuck and i removed the needle, tried to push it out as much as possible but failed.
it looked like rubber on the plunger "melted" onto barrel, got stuck and ive broken the plunger inside the syringe.

since then ive switched to different 1ml's and had no issues. plunger tip is plastic, not rubber. its not as smooth or "luxury" syringe, like bd, but i had no issues since then

 

[mattgray]

@oldgrey it seems like that is what is happening, I’ve noticed too that when pushing and pressing, the plunger seems to stick to the wall in a sense and deform to a certain extent, dragging behind in whichever way it is being moved (pushed/pulled). See the picture where it has gone crooked after pulling and stayed that way after the plastic handle piece detached from the plunger itself.

@PiscesMoon I draw with 23g 1” and inject with 25g 5/8” (deltoid injection), carrier oil is MIG812.
I have used these exact needles in the past with a larger syringe (3ml) without luer-lok. With this syringe, the injection went very smooth although it had its own downsides (imprecise measurements + air getting in through the attachment between syringe and needle). I did not warm the oil before but I doubt the viscosity/gauge are the problem since even without much oil in the syringe, without needle attached, the plunger still gets stuck.

@BabaJagga yes, that is what seems to have happened for me as wel. The rubber actually seems to deform as I push/pulled the plunger, increasing friction. And if I try to pull the plunger backwards after a few minutes of the injection, it will actually get so bad the plastic handle piece detaches as can be seen in the picture. I think I will also try and find these plastic-tipped syringes instead where the plunger isn’t rubber. I hope that will reduce friction.

 

[mattgray]

As for an idea of the force required: after the injection, I took the empty syringe without needle and without oil, and put in on my scale with the handle downwards, then I measured the force before the plunger started moving, which was about 4kgs.

This means I could put a 4kg dumbell on my syringe, and the plunger would just support it without moving, without any oil or needle. I imagine with the oil, and the needle, and inside my arm, the resistance will be even higher. As I said, I really had to squeeze as hard as I could to even get the plunger moving slightly.

 

[BigDadd7]

Hi @mattgray Some questions that may help us to advise on your situation..

What is the gauge and length for the syringe needles you have been using?

What is the carrier oil type(s) you are working with?

For any oils, have you tried warming the vial before drawing up the dose & injecting?

He said it happens even without the needle and when the barrel is empty. He has a batch of faulty syringes.

 

[Psy-chonaut]

He said it happens even without the needle and when the barrel is empty. He has a batch of faulty syringes.

Maybe?

I use the 3 cc version - and once in a while I win the lottery, and I get one that's 5-6 times harder to pull / push.....

 

[mattgray]

Maybe?

I use the 3 cc version - and once in a while I win the lottery, and I get one that's 5-6 times harder to pull / push.....

For me, it is ALL of them though, I’ve tried 3 syringes so far and they all were like this. I know they are a couple years old but the expiry date on them is november 2027, so idk if that could be the reason?

 

[BabaJagga]

View attachment 379888
View attachment 379889

@oldgrey it seems like that is what is happening, I’ve noticed too that when pushing and pressing, the plunger seems to stick to the wall in a sense and deform to a certain extent, dragging behind in whichever way it is being moved (pushed/pulled). See the picture where it has gone crooked after pulling and stayed that way after the plastic handle piece detached from the plunger itself.

@PiscesMoon I draw with 23g 1” and inject with 25g 5/8” (deltoid injection), carrier oil is MIG812.
I have used these exact needles in the past with a larger syringe (3ml) without luer-lok. With this syringe, the injection went very smooth although it had its own downsides (imprecise measurements + air getting in through the attachment between syringe and needle). I did not warm the oil before but I doubt the viscosity/gauge are the problem since even without much oil in the syringe, without needle attached, the plunger still gets stuck.

@BabaJagga yes, that is what seems to have happened for me as wel. The rubber actually seems to deform as I push/pulled the plunger, increasing friction. And if I try to pull the plunger backwards after a few minutes of the injection, it will actually get so bad the plastic handle piece detaches as can be seen in the picture. I think I will also try and find these plastic-tipped syringes instead where the plunger isn’t rubber. I hope that will reduce friction.

same thing happened to me. i have 3ml ones and they dont have this issue.
also i had 0 issues with regular test, only with tne...

go for different syringes. i like them a lot cause its high quality but they dont have little tip inside and there is bit of deadspace, also very expensive.

 

[Psy-chonaut]

For me, it is ALL of them though, I’ve tried 3 syringes so far and they all were like this. I know they are a couple years old but the expiry date on them is november 2027, so idk if that could be the reason?

Maybe they are all faulty as @BigDadd7 stated?

- Maybe they have been stored improperly before you got them (too hot, to cold - idk what 'cause' would cause the plunger rubber to become a 'stiffy')

Just a thought - try a couple syringes from the 'bottom' left and right, see if there is any difference at all...

 

[mattgray]

I agree with what you guys said and I believe the batch is simply faulty, whether it is due to a manufacturing error or simply improper storage, I do not know. But it’s nice to know that this is not how it’s supposed to be.

I have ordered a new batch of the same model of syringe (luer-lok) and also a different model without the luer-lok, both by BD and both 1ml.

I will update this post with the results once I get them which might take a while cause my pharmacy told me they had trouble getting their hands on the luer-lok 1ml syringes, so we’ll see how that goes.

Thank you all for the info

 

[Photon]

Even fresh out of the package, with no liquids inside and no needle attached, the plunger moves with high resistance.

Most of these syringes have lubricant in them (silicone oil), it should be easy to slide with nothing in it.

hey, i had same with these BD and TNE, something solvent related probably.

With regular test c in ussuall concentration i had no issues but with TNE, 23G needle, i had trouble even drawing the oil, heated.

i couldnt push everything in, 0,3ml was stuck and i removed the needle, tried to push it out as much as possible but failed.
it looked like rubber on the plunger "melted" onto barrel, got stuck and ive broken the plunger inside the syringe.

since then ive switched to different 1ml's and had no issues. plunger tip is plastic, not rubber. its not as smooth or "luxury" syringe, like bd, but i had no issues since then

The rubber used in these syringes are not compatible with the solvents used, but shouldn't really be a problem imo. I found it occurring most often with (1) heat, (2) eo and (3) high solvent gear (e,g pwo).

Braun produces chemical resistance syringes with no silicone oil and rubber. Alot more expensive tho. I'm guessing these are the ones you're referring to.

Post in thread 'Syringe plunger dissolving/melting?'

May 21, 2025

In my early days of TRT when I was dumber than I am now I prefilled syringes. One of the plungers on a luer lock syringe completely broke off after being prefilled 7 days. I’m thinking BA and carrier oil was the culprit.

But you are having it occur immediately which is strange. Nipro makes quality syringes so I doubt that’s the issue.

It's an inj oral..I got a feeling it might have a crap load of BA.
Nipros are from medlabsupply so i doubt its fake.

• Photon

•