Hi
@cyril.rayner, Humulin M3 is from my reading on medicines.org.uk and mixture of two older insulins: a short to medium acting insulin and a longer acting insulin.
I used to be on them separately from 1966 til 1984. And from my experience, not as professional advice or opinion, mind:
If you look at the action of Humulin M3 over time by clicking on the picture below you can see that it has two peaks where it is working most strongly to lower blood sugar.
They are at about 3 1/2 to 4 hours, and a bit less strongly, about 9 to 10 hours after injecting it.
Because you have your dinner after injecting Humulin M3, the sugar from your meal probably balances up with the 3 to 4 hour peak insulin -lowering action of the Humulin M3, although the sugar peak might happen nearer the 2 hours mark.
But 10 hours peak of insulin blood-sugar lowering effect is about ? 3 to 4 am. Sound familiar? No food there to balance that.
So that maybe why the hypos are happening at night/early morning.
Now, night-time hypos can be dangerous - at least there were for me and best avoided.
If you were to go along to your GP or Diabetes Nurse, and let them find the Humulin M3 profile picture like the one below (google 'pictures of profiles of Humulin M3') they could also see what is happening.
I cannot advise you what to do about your hypos but armed with this picture/profile I am sure your GP or Diabetes nurse should be able to help with possibility changing a dose or looking at a different and perhaps safer insulin to use.
Best Wishes
