Short answer: Keep unopened Humalog Mix75/25 in the fridge at 36-46°F (2-8°C) until the expiration date. At room temperature up to 86°F (30°C), a vial lasts 28 days and a KwikPen only 10 days, counting unopened and in-use time together. Opened vials may be refrigerated; an in-use KwikPen is not. It is cloudy and is mixed right before each dose. Do not use it if it froze. Source: Humalog Mix75/25 label, section 16.2.
What does the Humalog Mix75/25 label say?
Section 16.2: “Protect from direct heat and light. Do not freeze and do not use if it has been frozen.”
Humalog Mix75/25 US prescribing information, section 16.2 storage table.
| Form | Unopened, refrigerated | Unopened, room temp (up to 86°F) | In use (opened) |
|---|
| 10 mL multiple-dose vial | Until expiration date | 28 days | 28 days, refrigerated or room temperature |
| 3 mL KwikPen | Until expiration date | 10 days | 10 days, room temperature only (do not refrigerate) |
Table footnotes: “When stored at room temperature, HUMALOG Mix75/25 vial can only be used for a total of 28 days including both not in use (unopened) and in-use (opened) storage time.” “When stored at room temperature, HUMALOG Mix75/25 KwikPen can only be used for a total of 10 days including both not in-use (unopened) and in-use (opened) storage time.”
Why does the KwikPen only last 10 days?
That is the limit the table gives; the label does not explain it. Plain Humalog pens get 28 days, so the mix is easy to mix up. Because the 10 days count unopened and in-use time together, a pen that sat out unopened for 4 days has 6 days left once you start it. Keeping spares in the fridge keeps the full 10 days for when they are opened.
How is Humalog Mix75/25 mixed before a dose?
It is a white, cloudy suspension. Section 2.1 says it “must be resuspended immediately before use”, and that this is easier at room temperature.
- Vial, Instructions for Use: “Gently roll the vial between the palms of your hands at least 10 times.” Then “Gently move the vial up and down (invert) at least 10 times.” Section 2.1 gives only the inverting step for the vial (“carefully invert the vial at least 10 times”).
- KwikPen: “Gently roll the Pen between your hands at least 10 times.” Then “Move the Pen up and down (invert) at least 10 times.”
- After mixing, inject right away; if you wait, mix again. “Do not use if it looks clear or has any lumps or particles in it.”
What do the Instructions for Use add?
- Unopened vials: in the fridge until the expiration date; “Unopened vials should be thrown away after 28 days, if they are stored at room temperature.” “Keep away from heat and out of direct light.”
- Opened vials: “Store opened vials in the refrigerator or at room temperature up to 86°F (30°C) for up to 28 days.”
- Unused pens: “Unused Pens stored at room temperature, up to 86°F (30°C), should be thrown away after 10 days.”
- In-use pen: “Store the Pen you are currently using at room temperature [up to 86°F (30°C)]. Keep away from heat and light.” Throw it away after 10 days, even if insulin is left. Do not store it with the needle attached.
See the Humalog Mix75/25 dosing schedule, Humalog Mix75/25 side effects and NovoLog Mix 70/30, whose FlexPen gets 14 days.
How do you travel with it?
An in-use Humalog Mix75/25 KwikPen travels at room temperature, up to 86°F (30°C), for the rest of its 10 days; a vial for the rest of its 28 days. Unopened spares start using up that time as soon as they leave the fridge. Keep them off direct contact with an ice pack, since frozen Humalog Mix75/25 is not used.
- TSA allows medically necessary liquids over 3.4 oz in carry-on bags; declare them at the checkpoint for inspection.
- Unused syringes and pen needles are allowed when they travel with the injectable medicine.
- Ice packs and gel packs that keep medicine cool may go through frozen, partly frozen or melted.
- Keep medicine in your carry-on, not checked luggage, where you cannot control the temperature. Do not let it touch an ice pack directly, since most labels say do not freeze.
More in the travel guide.
Quoted from the current US label on DailyMed, not personalized advice. Labels change; the leaflet in your own carton, your pharmacist and your prescriber are the final word on how to store it.