"Low Dead Space" Needles in the news - like insulin syringes!

I had been using plastic insulin syringes for almost half a century, and only today did I realize what sort of technology was in them to help me not waste insulin.

Those following vaccine technology, you may have read that some clever practitioners are able to get 6 or even 7 doses out of a nominal “5-dose” vial of vaccine.

Turns out, the trick is to use a “low dead space needle” which is what our plastic insulin syringes have been using all along. Other than plastic insulin syringes, it seems most syringes on the market are like the 3 ones on the left below, with a removable needle and a lot of “dead space” (red area) that is medicine that has to be drawn from the vial but can never be injected.

The fourth one below, is a depiction of a plain old plastic insulin syringe. No removable needle, very little wasted “dead space”.

Is there any reason that plain old plastic insulin syringes couldn’t be used to with vaccines? Is the needle not long enough? I am truly “old school” and until recently used the half-inch insulin syringe needles until my doc put me on pens just a couple years ago. But maybe a half inch isn’t long enough?


Nice graphic to understand how much of a valuable and scarce resource like the Covid-19 vaccines can be saved simply by selecting a syringe with low dead space.

It’s important for this vaccine to be delivered intramuscularly (IM) and that requires a 1" needle at a minimum. This length will ensure that dependable IM delivery across a wide range of body types. The typical insulin syringe is often only 5/8" long


I remember AcidRock wrote up how to do IM injections of insulin (for faster absorption?) but I fail to remember the details. Yes I can see even the “long” insulin syringes not being right for IM injections into everyone (but maybe they were long enough for AcidRock?)

I’ve delivered many IM injections to myself for quicker corrections. My use of Afrezza inhaled insulin diminished my need for IM’s but I will use an IM when faced with trending toward DKA.

I do use the 1/2" insulin syringe to successfully reach my deltoid muscle. Dr. Bernstein uses this needle length to correct using an IM shot.

If you do a TuD search on IM injections you’ll find much discussion of this technique. Here’s a comment I wrote about IM injections that provides a link to Dr. Bernstein video on the topic.

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Some of the people using insulin syringes for IM injections also use “off-label” muscles like calves etc, which are much easier to hit, but not recommended for IM injections, since higher risks of nerve damage and other issues. They definitely would not do a vaccine in those spots. Generally the rec is either that spot on your arm (deltoid) or if need be the upper side of your thigh (I had to do my recent flu shot there because was having shoulder issues that would have worsened with the increased inflammation from vaccine). If someone has much body fat, a modern insulin needle will not work, especially in the latter region.

FWIW, I have been using the same 5/16 inch needles I use for all bolus injections in my deltoid for IM injection successfully.

Intramuscular injections hurt like hell. No thanks

Lots of people choose not to do IM injections, so you’re not alone. If you use Afrezza there would be no need. But I find it sometimes useful to more quickly bring down a high BG, by no means every day. I have found that there is pain only if your muscle being injected into is at all tense. So I make sure my arm is completely relaxed, and then it is pain free, similar to a subcutaneous injection.