Injection depth (minimum needle length)

[Manualtrt]

Hi.

Very basic question I think, but looking for confirmation prior to purchasing the supplies - couldn’t find the answer via search.

What’s the minimum depth of needle for a SubQ injection into stomach for HGH and peptides?

I currently use an 8mm, but was thinking of going to 4mm.

Primarily because it means I can use a 32g pen needle instead of 31g. Negligible difference but i am doing c. 4x subq pins per day, so looking to minimise scarring.

Thanks

 

[Ghoul]

Hi.

Very basic question I think, but looking for confirmation prior to purchasing the supplies - couldn’t find the answer via search.

What’s the minimum depth of needle for a SubQ injection into stomach for HGH and peptides?

I currently use an 8mm, but was thinking of going to 4mm.

Primarily because it means I can use a 32g pen needle instead of 31g. Negligible difference but i am doing c. 4x subq pins per day, so looking to minimise scarring.

Thanks

Personally I wouldn't go shorter than 6mm.

I've had injections not reach subQ and end up as "bubbles" just under the skin, which I'm sure isn't. great for absorption.

 

[Eddie.]

I'd say 8mm minimum.

 

[Manualtrt]

Thanks. That makes sense also 4mm gives no room for error and not having the needle fully into the skin.

Interestingly when I got my pharma mounjaro before going generic they issued 31g 4mm.

But I’ve subsequently ordered 31g 8mm - I’m going to stick with that for my glp-1’s and when I start HGH.

 

[Photon]

Thanks. That makes sense also 4mm gives no room for error and not having the needle fully into the skin.

Interestingly when I got my pharma mounjaro before going generic they issued 31g 4mm.

But I’ve subsequently ordered 31g 8mm - I’m going to stick with that for my glp-1’s and when I start HGH.

I use 33g 4mm

 

[Manualtrt]

Do you notice any long term difference with a 31g assuming you have done both?

 

[Photon]

Do you notice any long term difference with a 31g assuming you have done both?

I switched brands too when i went from 31->33.
I'm using the ones by Owen Mumford now, feels alot better than the older ones I used at 31g.

They have 34g too but i couldn't find it online when i bought the 33gs.

You can read the following study, they recommended 4mm for pen needles. At that point of time of the study, the shortest available syringe needle was 6mm, so they recommended 6mm for syringe.

https://www.mayoclinicproceedings.org/article/s0025-6196(16)30321-4/fulltext

​

A variety of studies of adult skin at injection sites using various imaging techniques have all shown similar results: the skin varies in thickness from approximately 1.25 to 3.25 mm in 90% of individuals and averages approximately 2.0 to 2.5 mm. Studies have included both healthy volunteers and persons with diabetes, and their results are consistent across age groups, sexes, body mass indexes (BMIs), and geographic locations.​

Recommendations​

The 4-mm needle is long enough to traverse the skin and enter the SC tissue, with little risk of IM (or intradermal) injection. Therefore, it is considered the safest pen needle for adults and children regardless of age, sex, ethnicity, or BMI.

The safest currently available syringe needle for all patients is 6 mm in length. However, when any syringe needle is used in children (≥6 years old), adolescents, or slim to normal-weight adults (BMI of 19-25 [calculated as the weight in kilograms divided by the height in meters squared]), injections should always be given into a lifted skinfold.

 

[sliderke]

The pen needles that our pharmacy gave for the tirzepatide pen were 4mm. But I prefer the insulin needles in 30g and 8mm.