@jayandminnie LDN stands for Low-Dose Naltrexone. Here is an article about it. There are many more articles on-line and also in this support group. https://www.drugs.com/medical-answers/low-dose-naltrexone-ldn-3570335/

If you have any more questions, I would be happy to answer them. I've been taking it for a year for my fibromyalgia and related severe insomnia and it has been a tremendous help to me.