If you've been prescribed a premixed insulin, you'll need pen needles for NovoLog Mix 70/30 FlexPen before your first dose. The pen is a prefilled, disposable Novo Nordisk pen, but in the US the needles are typically sold separately. This guide covers which needles fit, how to choose a length and gauge, and how many to keep at home so you never run short.
Which Pen Needles Fit NovoLog Mix 70/30 FlexPen?
FlexPen uses the standard screw-thread connection found on most US insulin pens. That means it works with Novo Nordisk's own NovoFine and NovoFine Plus needles, and with other standard-thread brands such as BD Ultra-Fine and BD Nano. Mixing brands is generally fine as long as the needle screws on straight and snugly. If a needle feels loose or won't thread on, stop and use a new one rather than forcing it.
- NovoFine Plus 32G 4mm Pen Needles (100 count) – Novo Nordisk's ultra-thin short needle
- BD Ultra-Fine 31G 5mm Pen Needles (100 count) – a popular standard-thread alternative
Best Pen Needle Size for NovoLog Mix 70/30
Most adults today are started on short needles. A 4mm needle is long enough to reach the fatty layer under the skin for most body types and lowers the chance of accidentally injecting into muscle. Common options:
- 4mm, 32G: the shortest and thinnest common size; a good default for many adults and for anyone nervous about needles.
- 5mm, 31G: slightly longer; some people simply prefer the feel.
- 6mm or 8mm: sometimes still used out of habit or on a provider's advice.
A higher gauge number means a thinner needle. Thinner needles often feel more comfortable, while slightly thicker ones can push larger doses a little faster. Your healthcare provider can confirm the right length and technique for you.
Premixed Insulin Tips That Affect Your Needle
NovoLog Mix 70/30 is a cloudy suspension, so it has a couple of extra steps compared with clear insulins:
- Resuspend before every injection. Follow the pen's instructions for rolling and tipping it until the insulin looks evenly white and cloudy.
- Attach a new needle each time. A used needle can dull, bend, or clog, and premixed insulin can crystallize in the needle tip if it's left on.
- Do the safety (air) shot. Priming confirms insulin is flowing through the needle before you dose.
- Remove the needle after injecting. Leaving it on can let air in or insulin leak out.
- Hold the pen in place. Keep the needle in the skin for the number of seconds the instructions specify after the dose counter returns to 0.
For a refresher on that last step, see our guide on how long to hold an insulin pen in the skin.
How Many Pen Needles Do You Need Per Month?
Since each injection uses one new needle, the math is simple: injections per day × 30 days. Premixed insulin is often taken twice a day, which works out to about 60 needles a month. Add a small buffer for a dropped or bent needle.
- 1 injection a day: about 30 needles a month, so a 100-count box lasts roughly 3 months.
- 2 injections a day: about 60 needles a month, so a 100-count box lasts roughly 7 weeks.
- 3 injections a day: about 90 needles a month, so plan on a box each month.
If you inject twice a day or more, a value pack can lower your cost per needle and cut down on reorders. Browse every size in our pen needles collection.
Quick Buying Checklist
- Standard screw-thread pen needle (NovoFine, NovoFine Plus, BD Ultra-Fine, BD Nano)
- Length and gauge your provider recommended (4mm 32G is a common starting point)
- Factory-sealed box with a clear expiration date
- Enough needles for one new needle per injection, plus a buffer
- An FDA-cleared sharps container or a sturdy household container for disposal
FAQ
Does NovoLog Mix 70/30 FlexPen come with needles?
Usually not in the US. Pen needles are typically bought separately, so check your pharmacy order or buy a box before you start.
Can I use BD needles on a Novo Nordisk FlexPen?
Yes. BD Ultra-Fine and BD Nano pen needles use the standard thread that fits FlexPen.
Can I reuse a needle with premixed insulin?
It isn't recommended. Use a new needle for each injection to help with comfort, accuracy, and hygiene.
This article is for general information only. Always follow your healthcare provider's guidance on your insulin, dose, and injection technique.
New to Zahrun? Use code WELCOME10 at checkout for 10% off your first order of pen needles.
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