[Keyword Density] - What % is acceptable between Keywords and LSIs?

I am writing review posts and I happen to have my keyword density around 3% because I am reviewing a product.
I think that is high, but I really don't know how to lower that without removing content or calling the product "it" instead of the real name.

The thing is that I tried to lower it by having many LSI.
My problem is that if you sum the keywords and LSI for the entire post, the % will be huge.

Should I worry or continue with it?

Ideal keyword density can vary by product, niche, etc.

One common suggestion is to look at the keyword density of the top ranking site(s) for your keyword(s) and to use that keyword density.

Or upload it as it is, see how it ranks, and then go back and edit it to see if you can improve it.

I think you have two option:
1- check top sites for your keyword to see which density they are using and use it and track your ranking
2- you can do some experiment with a random density and see if you please Google.

In my experience, I think there is no a fixed density for a given keywords. You need to take into account several things. There is a post on keyword density here made by phpbuild, it is really great and many thanks to him. Look for it in the forum, I guarantee that you will be enlightened about keyword density.
I hope that help