Well, as people have pointed out, there are at least two companies that have produced an object that attaches to an insulin pen -- which means lots of people have this problem. As one of those people, I went for the Timesulin product first as there was a special offer on it (I think it was around £20) -- got it for my disposable NovoRapid pens. And... it didn't work very reliably. The catch wouldn't always register whether the lid had been taken off (which triggered the resetting of the clock and therefore told you the last time you'd injected). Timesulin didn't offer an alternative but were very good and refunded me.
So I went to Insulcheck. This was a more cumbersome design (it attaches itself to the dial-end of the pen) so you might have to get used to using it. I had many problems with this product initially (the plastic would fall apart, like the reset catch wouldn't always catch). Each time, the customer services were very helpful and sent out a replacement. After about four issues of the product falling apart, I was told they had changed manufacturers as they'd had a lot of quality issues. Since then, I've not had any problems and it is a good indicator of whether I've injected or not.
Don't have the same product for my Lantus (I don't think it's supported). But I'd recommend the Insulcheck (now!).
Best of luck.
Gareth
So I went to Insulcheck. This was a more cumbersome design (it attaches itself to the dial-end of the pen) so you might have to get used to using it. I had many problems with this product initially (the plastic would fall apart, like the reset catch wouldn't always catch). Each time, the customer services were very helpful and sent out a replacement. After about four issues of the product falling apart, I was told they had changed manufacturers as they'd had a lot of quality issues. Since then, I've not had any problems and it is a good indicator of whether I've injected or not.
Don't have the same product for my Lantus (I don't think it's supported). But I'd recommend the Insulcheck (now!).
Best of luck.
Gareth