You have no experience so I don't blame you for just mirroring what you have googled. There's a good and bad in everything. Insulin can be a life saver but it is also very dangerous.

The side effects are hypoglycemia and risk Coma and death if not properly monitored.

Let me tell you from experience. A friend of mine fell into hypoglycemia a few years ago and although was saved in time by family members, suffered brain damage and now no longer acts like a normal person.

Now I have my own experience. This certain hospital HU** prescribed 12 Units of Insulin for my mother 3 Times a day before meals and another maintenance  dose (Diff Insulin) at 10 pm at night. We were not warned about the side effects and the 'so called'  trained nurse even told us to give the same dose as long as the reading was above 4.

Luckily I monitored her Blood Sugar levels constantly 4-5 times a day. Many Days her readings fell into the danger zone 3.2, 3.1, 2.8. 2.4..... Each time I managed to give her sugar in the nick of time to revive her.

For those busy people who can't monitor for the elderly , I fear many might have just trusted and followed what the hospital told them to do and I guess some would have died and the blame would be put on the disease without realising it was the Insulin causing Hypo that killed them.

For your info,  I am now only giving my mother a dose of 2 or 3 before meals to keep her levels in normal range. A huge difference from the 12 Units prescribed by the Hospital.  If I just give a few units extra units she will go into Hypo and put her life in danger again.

So now I am no longer risking my mother's life on Insulin just for a dose of 2 or 3.

And also for your info Bitter Gourd and other foodstuff might not be Insulin but it can lower and regulate your sugar levels , just how much depends on different people. I am trying to find natural alternatives to bring down her sugar , some may work , some may not  , I am sure I will find a better solution.

Doesn't mean Insulin is the only solution, unless you are type 1 Diabetes and your Pancreas no longer functioning.

Since you haf the blood glucose machine, why not do a simple test? Administer bitter gourd or some other natural food u think may help, and test it post 2 hours after consumption.