Syringe needle size question

[dgoldrich]

I am currently using a 31g 5/16 needle and it works fine for me. It will occasionally bend, but usually it is great. My friend just started injections and apparently her skin is much thicker and the needle keeps bending and breaking on her....does anyone have a recommendation for what size I should buy for her?

 

[GLP1Pharmacist]

Lower numbers = thicker. Maybe try 28/29G?

 

[StephKruze]

I currently use 31g, but my first month I used 29g and it was still very comfortable. You might want to try having her move to 29g first because it's supposed to be a nice "middle ground" syringe for comfort, speed, and sturdiness. If that still doesn't work, then 27g and 28g are used when you need a sturdier syringe or better flow because medication is thicker, but may not be as comfortable to use. Just my two cents from when I trying to determine what to purchase myself since I had to ask for an Rx to buy syringes where I live.

 

[Calm Logic]

Per Google Gemini, for her situation:

27 to 29 Gauge (most important)

1/2" length (optional, longer length for thicker skin)

 

[dgoldrich]

Thanks for the advice, I will try a lower number and a longer length needle

 

[ZippityDooDah]

Ironically I've been planning a "daily dose of wisdom" post on this very subject, but in the meantime here's my take starting with the outside diameter (OD) of the three most common insulin syringe size needle gauges in mm:

31G .2604mm
30G .3112mm
29G .3366mm

The difference between a 31G and 29G needle is .0762mm.

For reference, a human hair averages something like .16mm, so even completely skipping the 30G size we're literally talking about a thickness difference of around half that of a human hair. I'd be willing to wager that 99.99% of people are incapable of perceiving that difference in size when it comes to how a needle "feels" and it's entirely a function of psychology and not anything determined by the various corpuscles in our skin.

Honestly, everyone starting out should begin with a 29G syringe (I still recommend 8mm over 13mm, but that's another discussion for another day), and give themselves at least a half dozen injections before considering going with a higher gauge and even then only if there are compelling reasons like excessive bleeding or other contributing factors like skin conditions such as psoriasis, scleroderma, or related complications from diabetes.

So yeah, tell your friend 29G is the way to go.

 

[Calm Logic]

Similarly:

From a paramedic textbook, recommending no more than 8mm in length for 90-degree injection:

From a clinical skills text, recommending the 29G size for insulin syringes:



And why 4 mm is long enough for pen needles:

Optimising Insulin Injection Techniques to Improve Diabetes Outcomes - PMC

The effectiveness of therapy in patients with diabetes depends on the correct use of the insulin injection technique. However, despite many established recommendations and evidence that an effective insulin injection technique is essential to ...

pmc.ncbi.nlm.nih.gov

The safety and efficacy of the 4-mm pen needle have been assessed and proven in several clinical trials in adults and children, as well as in obese and nonobese adults with diabetes [5, 19]. Furthermore, the 4-mm pen needle has been recommended for use in most adult patients of all sizes where the lifting of a skin fold is not required (Fig. 1) [20].

[Not to scale]

 

[PackmanJohnny]

Similarly:

From a paramedic textbook, recommending no more than 8mm in length for 90-degree injection:View attachment 7790

From a clinical skills text, recommending the 29G size for insulin syringes:

View attachment 7791

And why 4 mm is long enough for pen needles:

Optimising Insulin Injection Techniques to Improve Diabetes Outcomes - PMC

The effectiveness of therapy in patients with diabetes depends on the correct use of the insulin injection technique. However, despite many established recommendations and evidence that an effective insulin injection technique is essential to ...

pmc.ncbi.nlm.nih.gov

[Not to scale]
View attachment 7793

21G for IM sounds like Hell on wheels. Almost a decade in the 25's still leave my glutes sore for a day or two.

 

[Calm Logic]

I'm using 27G for IM.

 

[Airborne Daddy]

23g for me for im

 

[PackmanJohnny]

23g for me for im

I had a client tell me he was using 18s bc thats what his doctor gave him.

my RN GF at the time confirmed thats common.

Doctors are idiots.

 

[d0se1]

I'm using 27G for IM.

Same

 

[Airborne Daddy]

I had a client tell me he was using 18s bc thats what his doctor gave him.

my RN GF at the time confirmed thats common.

Doctors are idiots.

Good gawd that's a harpoon. I've used that to self let a pint of blood when my hematocrit was too high to donate.

 

[peptidepower77]

I had a client tell me he was using 18s bc thats what his doctor gave him.

my RN GF at the time confirmed thats common.

Doctors are idiots.

The only time I've ever used 18g is for testosterone replacement therapy, and that's to transfer it to a 29g insulin syringe to inject later. It's a massive needle.

 

[PackmanJohnny]

The only time I've ever used 18g is for testosterone replacement therapy, and that's to transfer it to a 29g insulin syringe to inject later. It's a massive needle.

you pin oil with a 29? youre gonna be there for awhile...

 

[peptidepower77]

you pin oil with a 29? youre gonna be there for awhile...

I actually even use a 31g with subq cypionate in MCT oil. It goes just fine.

 

[desinr-gal]

I was given a 31G 5/16 to begin with for tirze. Has been perfect, until I got the other brand and they were the same guage, but I felt the poke. I switched back. But I was considering the 32G for pen needles. Why not? what are the concerns?
I also heard those using Glo liked longer needles as there was less ISR if it went deeper. So I was considering the 32G 8mm.
I keep seeing guys recommend the 29G but I cant understand why?

 

[AndyPanda]

23g for me for im

My butt hole is puckering just thinking about a 23g needle. 😝 I use a 27g 1-1/2 inch for IM.

 

[Calm Logic]

I've had 32G needles bend almost completely off.

I was given a 31G 5/16 to begin with for tirze. Has been perfect, until I got the other brand and they were the same guage, but I felt the poke. I switched back. But I was considering the 32G for pen needles. Why not? what are the concerns?
I also heard those using Glo liked longer needles as there was less ISR if it went deeper. So I was considering the 32G 8mm.
I keep seeing guys recommend the 29G but I cant understand why?

The 32G is more likely to bend. Even the weight of a small vial on top of it can bend the needle, if not put in the vial straight enough or if there is angular pressure. With repeated bending, the needle could even bend off, into one's skin.

 

[AndyPanda]

I was given a 31G 5/16 to begin with for tirze. Has been perfect, until I got the other brand and they were the same guage, but I felt the poke. I switched back. But I was considering the 32G for pen needles. Why not? what are the concerns?
I also heard those using Glo liked longer needles as there was less ISR if it went deeper. So I was considering the 32G 8mm.
I keep seeing guys recommend the 29G but I cant understand why?

@ZippityDooDah posted a factoid about syringe width a couple of weeks ago. The widths from 30 to 32 gauge were negligible, but I can’t find the post. I bought 30g easy touch because they were the smallest gauge I could find in half inch length. I can’t tell any difference between it and a 31g. I can’t only speak for the quality of the easy touch syringes though.

 

[Calm Logic]

Zip recommends 29G for subq (in this post above).

I just realized the 32G question is also about pen needles. I haven't had a problem with 32G pen needles since they don't have to go into a vial. The pen needles I have are shorter (4 mm), which also helps them seem sturdier.

 

[Eengineering]

I want to preface this by saying I know I'm really dumb and should have done my research:

I was alerted to the benefits of GLP-1 drugs beyond their weight loss capabilities. I am around 11-12% bf (take this with a grain of salt as this number comes from a fitness scale reading) and I wanted to microdose reta for these benefits. Having no prior experience with injecting, I read somewhere to use the top upper part of the thigh and had a 28g 1/2 syringe. I went in at 90° and I'm sure you can guess what happened. I ended up injecting IM which gave me a limb for the day and completely destroyed my hunger. Feel free to laugh/shame me.


So I think one of the most important things to consider is not only the gauge and length of needle but also the thickness of the subq layer you have at injection site and the angle you are injecting at.

 

[desinr-gal]

Zip recommends 29G for subq (in this post above).

I just realized the 32G question is also about pen needles. I haven't had a problem with 32G pen needles since they don't have to go into a vial. The pen needles I have are shorter (4 mm), which also helps them seem sturdier.

Yes the vial caps can be hard, I didn't realize that until I got the lypholized peps, The dang cap is an issue. That's another reason to switch to pens!

 

[micropapaya]

I am currently using a 31g 5/16 needle and it works fine for me. It will occasionally bend, but usually it is great. My friend just started injections and apparently her skin is much thicker and the needle keeps bending and breaking on her....does anyone have a recommendation for what size I should buy for her?

I like 29g needles because I also have trouble with needles bending