Problem Filling Luer Lock Syringes

I’ve Googled this to see if there was a trick but haven’t found anything indicating there is. For the life of me I can’t seem to get the hang of drawing into these. I have no problem with my 27g and 28g insulin syringes at all, although they take a while. I’ve tried both a 3ml 25g and a 1ml 27g luer lock and had problems with both, like taking 10 minutes to get 1ml. All I get is air. I’ve been pinning test cyp 2x week for 7 months with the insulin syringes and have vast other experience with insulin syringes. I gave my previous dog 2x day injections for years and inject my wife’s meds once a week. Is there some trick like not tightening the needle to draw or some other thing?
The liquids I’ve tried are test cyp in both cottonseed and grapeseed oil at 100mg/ml, 200mg/ml and 250mg/ml and some deca at 200mg/ml if that’s relevant.

Always taken too long for me too…call me impatient. I load the syringe with an 18g or 20g in a 1ml syringe and then swap out with a 30g for injection.


You’re probably better off drawing with a “blunt fill” needle. They are usually 18G. That way you’re not blunting you’re injecting needle also.

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I just ordered some 18g needles. That seems like the easiest solution. Still not sure why I can fill a 28g insulin syringe but not a 25g luer lock :^ /

Seems like the blunt tip would put quite a hole in the stopper.

I use a 23ga to draw and backfill. Mostly because it comes in the box with the amp where I normally buy it in Central America. I works great and doesn’t make a gian hole, and in a pinch I can do the actual injection with one.

I use a 20G to draw my test, then switch needles to inject. Have you tried injecting air into vial first to created a positive pressure before drawing? When I get air, I just push it back into the vial and continue drawing. Of course while keeping everything upside down and the needle tip always submerged in the liquid!

Yes I inject air. Like I said, I can load a 27 and 28g insulin syringe fine. The 25g luer lock should be a breeze compared to those but I can’t do it. I just received my 18g needles so I’ll just draw with those and then swap needles.

I fill with a 25g just fine. Just have to have an understanding of hydraulics. Thats all.

OK so explain what the difference in hydraulics is between a 27-28g insulin syringe and a 25g luer lock please ;^ )

I use 27ga easy touch leur lock and also 27 ga easy touch insulin and have never had an issue or noticed a difference between the two. I also tries 30ga insulin and i did not have the patience for them… too slow…

You insert the needle in, flip the vile over and slowly pull the plunger out, oil will slowly get drawn into the syringe. Pull further back and an air bubble will become very apparent, push the air back into the vile, and allow the oil inside the syringe to reach the top and connect with the oil that is in the needle. Now slowly pull the plunger back out again, and the syringe practically fills itself.

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That’s exactly how I do it, thanks. BTW I tried my 18g needles to draw yesterday and it practically spilled out.

I use 18g needle to draw, and 25g to inject. I use BD luer lock.
Put the 18g needle on, fill the syringe with the same amount of air that you’re filling the syringe with Test. Inject air into vial, and that helps push oil into syringe.

It’s not rocket surgery.

Thanks Mr Wizard…as you can see from my previous post that’s what I’m doing and the problem is solved.
And ya know, I don’t think people read before posting. I’ve already said I’ve been filling syringes for years with no problem, it’s just the luer locks that were giving me an issue so I asked if there might be a trick to those.