@kjs831 Yes, those are side effects, but as this article explains very few people experience them, "Naltrexone side effects low dose are typically mild and infrequent, affecting fewer than 8% of patients. Most people tolerate this medication well, but understanding what to expect helps you start treatment with confidence."
https://www.directintegrativecare.com/post/naltrexone-side-effects-low-dose
Regarding insomnia, as the article says, most sleep problems with LDN resolve in a couple weeks. In fact, LDN is often used to treat insomnia. https://neurolaunch.com/low-dose-naltrexone-sleep/

The other drugs typically prescribed for fibromyalgia (Cymbalta, Lyrica, Savella) are often addicting and can have severe side effects and only work for about 30% of the people who take them.

I only offer this as an option to check out because it basically cured my fibromyalgia and insomnia. I feel like it "re-set" my body back to where it was before getting fibro For me, it was a miracle.

It doesn't work immediately, as you have to start at a low dose and taper up to the maintenance dose, usually 4.5mg/day. After that it can take a couple months to begin to notice improvement. The only side effect I've noticed is vivid dreams, but not nightmares.