It's my 4th injection today so I decided to go up to 5mg early by using the leftovers in the pen.
This is not medical advice, just what I chose to do.
I ordered these needles https://www.amazon.co.uk/dp/B0C4HC51NY
I used the pen for the last dose as usual and then used the syringe above to extract what was left. (Pull the plunger back slowly otherwise you get lots of air bubbles.)
I managed to get 0.7ml out which is slightly more than 1 dose so it's definitely worth doing.
The needle is slightly bigger and longer but didn't hurt much more than the pen.
Before injecting, I made sure to hold the syringe with the needle upright, flick it to get the air bubbles to the top, and squeezed the plunger until they were gone. Then I injected it in a different spot of my stomach than I used for the pen.
I'm hoping by doing this I can get an extra dose out of every pen to help with the cost.