Pen Needles for Humalog Mix 75/25 KwikPen: Which Fit, Best Size, and How Many to Buy

If you use a Humalog Mix 75/25 KwikPen, you need a fresh pen needle for every injection, and the box doesn't include them. The good news: finding pen needles for Humalog Mix 75/25 KwikPen is simple once you know what fits, which length and gauge most people choose, and how many to keep on hand. This guide walks through all three, plus a few tips specific to premixed insulin.

Which Pen Needles Fit the Humalog Mix 75/25 KwikPen?

The Humalog Mix 75/25 KwikPen is a disposable, prefilled pen made by Eli Lilly. Like Lilly's other KwikPens, it uses the standard threaded tip found on most US insulin pens. That means widely sold screw-on pen needles from major brands are designed to work with it, including:

• BD pen needles, such as BD Ultra-Fine and BD Nano 2nd Gen
• NovoFine and NovoFine Plus pen needles
• Most other standard "universal" screw-on pen needles

Always check the needle packaging for a compatibility statement, and screw the needle on straight until it feels snug. If one won't seat properly, our guide on pen needles that won't attach covers the common causes.

Best Pen Needle Size for Humalog Mix 75/25

Humalog Mix 75/25 is injected into the fatty tissue under the skin, like other insulins. Current injection-technique guidance generally favors shorter needles for most adults, because they reach that layer reliably while lowering the chance of injecting into muscle.

• 4mm, 32G – The shortest, thinnest common option. Popular with first-time users and anyone who wants maximum comfort. Example: NovoFine Plus 32G 4mm (100 count).
• 5mm, 31G – A slightly longer choice some people prefer, still short and fine. Example: BD Ultra-Fine 31G 5mm (100 count).
• 6mm–8mm – Longer lengths some people have used for years. If you're thinking about switching lengths, talk it over with your healthcare provider first.

Your doctor, nurse, or diabetes educator can recommend the length and technique that fit your body and routine.

Tips for Injecting a Premixed Insulin Pen

Premixed insulins like Humalog Mix 75/25 are cloudy suspensions, so a few steps matter more than with clear insulins. Follow the pen's Instructions for Use, which include:

• Re-mix before each dose. Gently roll and tip the pen as directed until the insulin looks evenly white and cloudy. Don't shake it hard.
• Use a new needle every time. A used needle dulls quickly and can let air or insulin leak. See why pen needles shouldn't be reused.
• Prime (safety test) the pen before each injection, as the instructions describe.
• Hold the needle in the skin for the count listed in the instructions after the dose is delivered.
• Remove the needle after each injection and put it in a sharps container.

How Many Pen Needles Do You Need?

Premixed insulin is often taken one to three times a day, but your own schedule comes from your prescriber. A simple rule: one needle per injection, plus a few extras for priming mistakes or a needle that gets bent.

• 1 injection a day: about 30–35 needles per month
• 2 injections a day: about 60–65 needles per month
• 3 injections a day: about 90–95 needles per month

At two or more injections a day, a 100-count box runs out in roughly a month to seven weeks, so value packs like the NovoFine Plus 200-count can cut down on reorders.

Quick Buying Checklist

• Standard screw-on pen needle from a known brand (BD, NovoFine, etc.)
• Length and gauge that match what your provider recommends (4mm or 5mm is common)
• Sealed, unexpired packaging
• Enough for your monthly injections plus a small buffer
• A sharps container for safe disposal

FAQ

Do pen needles come with the Humalog Mix 75/25 KwikPen?
No. Pen needles are sold separately.

Can I use the same needles I use for Humalog KwikPen?
Yes, standard pen needles that fit one Lilly KwikPen are made to fit the others. See our Humalog KwikPen pen needle guide.

Is a 4mm needle long enough?
For most adults, short needles are considered effective for under-the-skin insulin. Ask your healthcare provider what's right for you.

Ready to restock? Browse all pen needles at Zahrun, and use code WELCOME10 at checkout to save on your order. This article is general information. Follow your healthcare provider's guidance for dosing and medical decisions.