No, unfortunately insurance doesn't cover any over the counter vitamins and supplements as far as I know. I posted my neuropathy journey in another discussion here - https://connect.mayoclinic.org/comment/310341/. But to answer your question on how long it took to experience an improvement, I started taking the supplements in Sept 2016 when the numbness was in both feet and legs from the toes to just below the knees. In early Dec 2016 if felt like the numbness receeded some and it was then a little above the ankles. All of this is subjective on my part I've had no additional testing done to prove it's better one way or another. Fast forward to today and for the past six months or so I have more feeling on the bottom of my feet. I'm also doing a lot of other things trying to improve my overall health including being about 40+ pounds lighter than I was in 2016.

I've always been labeled pre-diabetic and have worried about diabetes. I've recently been focusing on learning more about Metabolic Syndrome and how it affects my overall health and it's relationship with diabetes and I ran across a connection with neuropathy which was interesting. That got me started on low carb healthy fat and intermittent fasting to help with the weight loss, improve my A1C and related labs. If you are interested here are a few links including one to a discussion on low carb healthy fat and intermittent fasting information.

The Metabolic Syndrome and Neuropathy: Therapeutic Challenges and Opportunities:
-- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3881591/

Metabolic syndrome as a risk factor for neurological disorders:
-- https://pubmed.ncbi.nlm.nih.gov/21997383/

Low-carb healthy fat living. Intermittent fasting. What’s your why?
-- https://connect.mayoclinic.org/discussion/low-carb-healthy-fat-living-intermittent-fasting-whats-your-why/