You can try it and if the side effects are too concerning, you might wish to switch to something else. You can try some other sleep aid, since you indicate that's its purpose for you.

I take higher dose Seroquel. Actually, I combine 400 mg of the extended release with 200 mg instant release (total 600 mg). I've been on more. It is used mostly for moodstabilization for me. Any sleep aid aspect is subsidiary. I have taken small dose in the past, for various reasons. I don't think small dose gave me any significant side effects. Higher dose does, but the value of the medication's efficacy exceeds side effects for me.

We can all react differently to medications, even ones who tend to cause side effects in many. As for weight gain, my greatest gains were due to depression, not Seroquel. I'll say that other meds did cause notable weight gain for me. For the last 13 years, I've weighed less than 13 years ago. During these last 13 years, I've been on high dose Seroquel XR for about 8. I do weigh about 15 lbs more now than I did 20 years ago, before meds, but many people do. I'm over 50.