I got one a year ago and it's been AMAZING! I wish I hadn't waited as long as I did to finally get one. I use it every night to sleep, and it definitely helps. I also use it during the day when I need it (anxiety, sensory overload, meltdowns etc.) Make sure you get the correct weight. The general rule is 10-12% of your body weight plus one pound. But it can be up to 20% of your body weight. (It think reason behind the maximum weight is because too much weight can cause blood clots or something if the weight is on you for a long time. I could be completely wrong about that though.)
Mine is 16 pounds, 42x72 inches, and cost $145. I got mine from this company https://magicweightedblanket.com , but I know there are a lot of sellers on Etsy that sell adult blankets for a lot less than $300 too. (Also, if you have a proven medical need for it, like a dx of autism, a weighted blanket is a tax deductible medical expense.) And there are lots of tutorials on how to make your own if you know how to use a sewing machine.
I really like mine. It's cotton and only has the poly pellets in the inside so it's not too hot for summer, or at least for the summers in Connecticut. The one thing I don't like about it is that the squares of the poly pellets are large. I sleep on my side, so with large squares, the pellets tend to slip to the edges and off my side, so I have to pile the blanket on top of me when I'm on my side. But it's well made and machine washable, so I think it will last me for many years.
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"Curiosity killed the cat." Well, I'm still alive, so I guess that means I'm not a cat.