No, none of them are/have any stimulant properties, and insomnia is not side effect associated with any of them.
Though on first weeks when I first time researched GW, I felt so extremely energetic that I remember I stayed up longer than usual, and waked up earlier, so I slept less overall for few weeks. Not insomnia at all, I could have slept if I just wanted to, I just felt so damn good I didn't want to waste my time being a sleep, lol!
After two weeks at max on GW research, I gave some thought to it, and fixed my sleeping pattern to normal without any problem.
So I don't think any SARM or GW-501516 would actually cause insomnia I have never seen before anyone mentioning trouble sleeping on them, generally people feel really good on SARMs and when you notice the incredible endurance and energy boost from GW you might feel like you don't need as much sleep as you did before. Energy you get from researching GW is not comparable to any stimulant energy (caffeine, Clen, DMAA, ephedrine etc.) which can cause some really annoying problems with insomnia. There's just not anything similar to GW, it's remarkably different from stims, and completely in the league of its own.
Yes, like you can probably tell if you red this far I really love GW, and can't wait to get started on my next research project on it, lol!
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