4mm Needle length

[Landrover Jason]

I’ve been using 6mm needles, recently i was advised to go to 4mm which I did.
I’m convinced that novo rapid is less effective on 4mm needle…….. is this just me dreaming this.
What are decision points around needle length for T1?

 

[rebrascora]

A shorter needle is less invasive and therefore less damaging to injection sites I would have thought and the insulin only needs to be injected into subcutaneous fat. It would probably be quite unusual for someone to have skin thicker than 4mm..... unless someone is injecting through clothing, which is probably not recommended, so 4mm needles seem to be the norm for most of us, I believe.

 

[Landrover Jason]

Thanks that’s helpful.

 

[rebrascora]

Thinking about it, I wonder if 6mm needles might be useful for people who have developed lumpy injection sites, to help get the insulin beyond the lipohypertrophy, but ideally you want to avoid those lumpy sites not make them worse by injecting longer needles into them.
Do you have lumpy sites?
I will confess I have no real knowledge of the subject, I am just thinking it through with as much logic as I can muster this morning. Hopefully others will chip in who have more experience or knowledge of this. I am reasonably confident that 4mm needles are standard issue for most of us.

 

[JJay]

Hard to believe, but when I started this malarkey 30 years ago, the needles were 12mm! But then we were told to pinch up the skin and inject into the resulting hillock. I actually found half a box of 6mm needles when were clearing out our boat for sale in 2021, so I must have been using them at some stage in the previous 10 years.

 

[trophywench]

@JJay - 20+ years ago I was mega sensitive to Novorapid to the extent that I injected it when my meal was in front of me and I'd frequently be hypo within the first few minutes of eating, so had to inject in the middle of the meal. This was with 5mm pen needles and ditto cannulas, then Roche stopped the 5mm 'soft' cannulas so I had to swap to 6mm.

Now having changed my pump and consumables to Ypso - for the first time in my life I'm using a steel cannula and it's 4mm. Hell thought I. OMG - my sensitivity to Novorapid has been restored, though I've been using it now since just before the turn of the century!

 

[Bruce Stephens]

Thinking about it, I wonder if 6mm needles might be useful for people who have developed lumpy injection sites, to help get the insulin beyond the lipohypertrophy, but ideally you want to avoid those lumpy sites not make them worse by injecting longer needles into them.

Yes, I doubt that's a recommended reason for using longer needles!

Here's a paper saying that yes, virtually everyone should be using short needles (admittedly it's saying that mostly in the introduction before giving a case where maybe a longer needle is appropriate).

Nontraditional Considerations With Insulin Needle Length Selection - PMC

Ensuring the correct delivery of insulin is essential in the treatment of diabetes. Both proper injection technique and needle length are important considerations for adequate insulin delivery. There have been several studies demonstrating that BMI ...

pmc.ncbi.nlm.nih.gov

 

[dannybgoode]

My team seem to have settled on the compromise position which is 5mm needles

 

[Bruce Stephens]

My team seem to have settled on the compromise position which is 5mm needles

Doubt 4mm vs 5mm makes much difference.

 

[dannybgoode]

Doubt 4mm vs 5mm makes much difference.

So do I. Just what I got prx'd from the outset 🙂

 

[nonethewiser]

I’ve been using 6mm needles, recently i was advised to go to 4mm which I did.
I’m convinced that novo rapid is less effective on 4mm needle…….. is this just me dreaming this.
What are decision points around needle length for T1?

Can't see it making any difference, sure when starting on novorapid was using 8mm needles then went on to use 4mm before switching to pump, injection site issues can affect how insulin is absorbed, could it be that?

 

[Landrover Jason]

It could be, although it could also be me. I switched to 4mm at the same time as switching jobs and becoming more home based….. probably more to do with increasing sedentary work. I wanted to get a sense of how different needle lengths might affect absorption. From the input above its seems it doesn’t and I should relax and move more
thanks all

 

[ET6]

Diagnosed in December 2024 I was sent home from hospital with 4mm. My surgery must have made a typo on my NHS app and put 5mm so when I ordered a repeat prescription- I didn’t realise until I noticed the needle cap colour was different but I definitely noticed a difference when injecting! Who would have thought 1mm would make a difference- it really did. Perhaps I’m just a wimp and super sensitive I’ve now reordered the 4mm again!

 

[Bruce Stephens]

Who would have thought 1mm would make a difference- it really did.

Doubt the length made the difference but I think 4mm needles are usually 32G (0.23mm) while 5mm are usually 31G (0.25mm), so if you're getting 5mm they're probably a bit thicker.

I'm not sure whether the needle difference was an accident or whether there's just some slowness in changing defaults in GP surgeries. I'd be surprised if a hospital team wasn't suggesting 4mm 32G needles for (almost) all patients but I wouldn't be surprised if some GP surgeries had older recommendations.

I've no idea whether 5mm was ever a general recommendation but I can imagine it might have been. I can imagine a non-specialist being worried about switching directly from 8mm (which was once a recommended length) to 4mm and deciding on 5mm as safe. Not that 5mm is right: 4mm seems well established now.

 

[JJay]

Doubt the length made the difference but I think 4mm needles are usually 32G (0.23mm) while 5mm are usually 31G (0.25mm), so if you're getting 5mm they're probably a bit thicker.

I'm not sure whether the needle difference was an accident or whether there's just some slowness in changing defaults in GP surgeries. I'd be surprised if a hospital team wasn't suggesting 4mm 32G needles for (almost) all patients but I wouldn't be surprised if some GP surgeries had older recommendations.

I've no idea whether 5mm was ever a general recommendation but I can imagine it might have been. I can imagine a non-specialist being worried about switching directly from 8mm (which was once a recommended length) to 4mm and deciding on 5mm as safe. Not that 5mm is right: 4mm seems well established now.

My prescribed needles are Carepoint 4mm/31G. I was once given Finepoint Ultra 4mm/32G by mistake - such a difference! No chance of getting the prescription changed though - way more expensive.

 

[Bruce Stephens]

My prescribed needles are Carepoint 4mm/31G. I was once given Finepoint Ultra 4mm/32G by mistake - such a difference! No chance of getting the prescription changed though - way more expensive.

Really? Surgeries differ, I guess.

I get Carepoint GlucoRX Ultra needles, 4mm 32G (doesn't say "Finepoint" anywhere that I can see but it may well be that). It does look like the 32G ones can be much more expensive, though it looks to me like sometimes the 4mm/31G ones are the same price. But maybe the NHS costs are more clearcut.

 

[rebrascora]

I have the same ones as you @Bruce Stephens I can't remember what I had before but interestingly they often clogged when using my Levemir, but the Carepoint Ultra 4mm 32G never have. I assume it was something to do with the coating on the previous ones that reacted with the Levemir. They were a different brand.

 

[JJay]

Really? Surgeries differ, I guess.

I get Carepoint GlucoRX Ultra needles, 4mm 32G (doesn't say "Finepoint" anywhere that I can see but it may well be that). It does look like the 32G ones can be much more expensive, though it looks to me like sometimes the 4mm/31G ones are the same price. But maybe the NHS costs are more clearcut.

Getting anything decent out of our ICB is like the proverbial blood out of a stone

 

[SimonP]

I started with 12mm screw on needles when I had Mixtard 50 way back. The syringes I used were 12.7mm (perhaps that's a metric labelling from half an inch), I'm pretty sure that insulin was also marked as being both subcutaneous and intramuscular in those days too (for old-school much slower insulins).

If you are injecting into muscle, it hurts more, and the insulin will also be absorbed faster. This is no longer the recommendation though.