I've been taking gabapentin for fibromyalgia pain since 2018. I started with 600 mg at first, and slept like a baby for the first time in years. I wouldn't say that the sleepiness increased with it, in fact it's been better probably because I can sleep through the night more often. It also helped tremendously with the awful restless leg syndrome that had me wanting to walk up the walls throughout the night. One thing: I did need an up in dosage two winters in, when we had a really bad winter and the pain heightened quite a bit. The doc right away upped my dosage to 1200 mg a day, half of it at night and the rest at 2 different times during the day, and the relief was impressive. I still have rough days about 2/3 of the year, mostly related to the weather, but I'll never go back on duloxetine after using gabapentin. With fibromyalgia, there's just no fixing this, and still trying to deal with the hand we've been dealt. But I've had virtually no side effects at all from the gab, for me it's been like a miracle drug at times.

Also, I was a medical marijuana patient for one year before I discovered the gabapentin. I'd say it was somewhat helpful with the pain and sleep problems but it just wasn't affordable.