I was told levemir lasts 12-16 hours with it peaking around then, unfortunately I was moved recently from levemir Detemir, to abasaglar glargine, good job I knew the difference even if the doctor thought they were identical treatments, I was on 40 units levemir, 20 morning 20 night.... I trialed this with the Abasaglar but knew it was more potent, so I am now on 15 morning 15 night. Youre told to use Glargine once daily, but I find this usually causes hypos more often, we know ourselves better than anyone... good luck.