I use lantus and don't notice it jamming but it doesn't do the same thing every day. I think the dose isn't always the same. I eat the same macro dinner everynignt and usually go to bed in the 80's. Take 2 units and some nights I drop like a rock 40 US ) and some nights I ha e. A30 point rise.
Refillable pens aren t available here.
As a side note I just had my refillable humalog pen jamming and not delivering so I called and they're replacing it. Good thing I had a back up!!