How often should I change insulin pen needles to reduce pain?
Patient's Query
Doctor, I have been using insulin for a long time with a pen. To save cost, I sometimes reuse the same pen needle. Usually I change it after 2 or 3 injections.
But if I use it more than that, the injection starts becoming painful, and sometimes I feel more resistance while pushing the pen.
Someone told me a needle should be used only once, and another person said twice is okay. I am confused.
How often should I actually change insulin pen needles? Does reusing needles cause any other problems besides pain, like lumps under the skin or wrong dose? If I am using vial and syringe sometimes, does the same rule apply there also?
Doctor Answers
You are noticing a real issue. A reused needle becomes blunt and slightly damaged, so the prick becomes more painful. It can also tear the skin more, and that can lead to bruising.
What do injection technique guidelines advise?
FIT and other injection technique recommendations clearly discourage needle reuse. Pen needles are designed for single use. Reusing increases the risk of:
- More pain because the tip loses sharpness and the silicone coating reduces
- Lipohypertrophy (lumps or thickened fat under the skin), which can make insulin absorption unpredictable
- Dose problems and leakage, especially when needles deform
- Contamination risk, since sterility is lost after first use
So the practical advice I give in OPD is simple:
- Best practice: change the pen needle every injection.
- If someone reuses due to cost, limit reuse as much as possible, and the moment you feel pain, resistance, bending, or a dull prick, change it immediately.
Why a fresh needle feels “painless”
A new needle is sharp, straight, and lubricated. After multiple uses, the tip can develop tiny bends and roughness, and that is enough to increase pain.
For vial and syringe also, the same safety logic applies. They are meant for single use and reuse can increase discomfort and injection problems.
If you are getting repeated pain, also check these:
- Are you injecting into the same spot repeatedly
- Do you have lumps at injection sites
- Are you using the correct needle length and technique
Fixing needle reuse and site rotation often reduces pain significantly.
References:
- https://pmc.ncbi.nlm.nih.gov/articles/PMC4366768/
- https://static1.squarespace.com/static/636e507501d1fa72da31dd2d/t/65f20b3f1ad37a4af5629a57/1710361413577/FIT+UK+Guidelines+5th+Ed.pdf
- https://www.sciencedirect.com/science/article/pii/S0025619616303214
- https://journals.lww.com/indjem/fulltext/2022/04000/effect_of_reuse_of_insulin_needle_on_glycaemic.13.aspx
Disclaimer: The information provided in this Q&A is for educational purposes only and should not be considered as medical advice. Always consult with a qualified healthcare professional for personalized medical guidance and treatment recommendations.