Hi
@Detritus
Your profile is incomplete, so it doesn't say what treatment method you are on.
If you go to your profile and complete the missing fields, then your type of diabetes will appear underneath your profile pic next to each post, and your medication (or lack of) will be visible in your profile so that people can know your situation and give a response that fits your situation.
At the moment it is really difficult to answer your question, since a reading of 4.1 mmol/l would mean different things to someone on insulin, or on a diet and exercise regime.