This is interesting. On another group a person who has a myriad of issues including foot neuropathy says that now that she's taking Melatonin, the nerve pain is reduced.

I started with 1/4mg Melatonin which is in my sleep combo, but have been taking 1.5mg in the last 5 months or so and my goodness the tingling etc in my feet have been so reduced. My issues with nerve pain stem from arthritis and surgery on the right side of my body, hip replacement issues.

Could melatonin drug treat neuropathic pain? - Futurity

Interesting for sure.