Instruction: Extract information from the supporting document to answer the given question.

Input:
Question: How sturdy are these on a full sized bed with two adults? Thanks.
Document: They're plenty sturdy, and raise the bed by about seven inches (removing the casters lowered it by three, then these added ten).
Worth the extra price for these ones instead of just risers. These fit perfect on the frame and are very sturdy. We have a california king memory foam, and it supports them very well. Doesn't rise the bed too high either.
Can't use this on any bed with a headboard. The  pegs are too large to fit in the frames of the two twin beds in my house. If they happen to fit your frame, they appear to be strong enough not to tip over like the inexpensive bed risers.
So far so good ... Heavy bed frame and two twin box springs and a heavy king size bed used with these . Holds all of that along with my wife , daughter and dog . I would def recommend these supports .... Wish they were a little cheaper !
These didn't work for our king frame. The middle two supports on our frame aren't wheeled, so the metal on the frame is longer there to balance with the others that do have wheels. Due to this, when we installed the risers, the bed didn't sit level. Amazon is taking them back, but we have to pay shipping because they are placing the fault on us.
These are just what I was looking for and simple to use! Very sturdy too! Would definitely recommend this product!
After reading all the reviews, I tried these. They are very stable and I recommend them. In essence, they give you about 2 inches more storage space, but it is sure nice to make up the bed without breaking my back. The two inches do not create a problem getting on and off the bed, but the two inches make a lot of difference when tucking in the sheets.
I have a heavy-duty 9 leg frame for my Cal King. These bed risers appear to be well made and are VERY sturdy. Anyone who says these are unstable probably just has a cheap frame. Using this product will lift the bottom of your frame approximately 10&#34; off the floor. Couldn't ask for a better product.
I used to have risers where the feet of the bedframe just sat on top of them, and the whole bed kept falling over if you sat on it too hard at an angle. These are a lot more secure, because the legs of the bedframe actually fit right into the risers. I only have two slightly negative comments:1)  There was a part missing when it arrived (the legs didn't fit correctly without these clip thingies).
I bought these for an older bed frame given to my grandfather, which I discovered the hard way used a different sized Pin for the leg. Meaning, that these wouldnt fit. I ended up finding some other bedframe that was much newer, and it worked fine, but fair warning, if your Hollywood frame is any older than about 50 years old, you might have to find a different frame or forget about buying these.Other than that problem, Its amazing.
Answer: I have a queen size bed and my husband and I have engaged in plenty of adult activities without any issues whatsoever from these. Probably the best ever!