Lantus Effectivtiy as it gets old

Does anyone else notice lesser effects from the Lantus as it gets closer to the 28 day expiration date?

It seems like I have to cut my dosage down when I start a new one and then increase it as it gets older.

Yep. I consistently had this happen with Lantus. It was kaput by day 28 & starting losing potency by 24-25th day. I'm doing far better on Levemir. An open vial lasts 6-8 weeks & Levemir doesn't sting. I also had Lantus lows when it peaked. I find Levemir more stable & level.