Many studies have been done to show that shorter and thinner needles, (for example the 4mm x 32G pen needles) are suitable for most individuals. Always consult your healthcare provider when choosing or changing your pen needle size.

Pen Needle Sizes: 4mm, 5mm, 6mm, 8mm and 12.7mm
*Photos enlarged to show detail. Sizes are not to scale

The dose amount and your physical makeup will play an important part in which length and gauge is right for you. If you are taking a large volume dose you may want to choose pen needles with larger diameters such as a 29G or 30G which allows faster flow of medication through the needle. Although, recent innovations in pen needle cannula have introduced a new thin wall technology.

A person’s body makeup should also be taken into consideration when choosing the needle size, but no matter your BMI, the thickness of skin stays fairly consistent. This allows for most people to use shorter needles a 4mm or 5mm and get the same results as with the original longer needles. Consult with your medical provider to determine the correct needle size for you.

Insulin should be delivered just under the skin into the subcutaneous tissue and shorter needles provide this. Shorter needles also have the added benefit of a one hand injection technique as there is no need to “pinch-up” the skin to ensure avoiding injecting into the muscle. According to the review of 157 relevant clinical papers by 127 experts from 27 countries it is noted that even in obese patients, needles shorter than 8mm have equal efficacy and reduce the chance of an intramuscular injection.*

* Hirsch LJ et al. Comparative glycemic control, safety and patient ratings for a new 4mm x 32G insulin pen needle. Current Medical Research & Opinion 2010; 26(6):1531–1541
WCF009 Sizes A 10/06/2015