Don't bother loading
Take 5g a day. Every day. Forever. Seriously.
There's research supporting use by everyone, including your grandma.
Get your kidney function checked in a few months. (Hopefully you have baseline numbers from a while ago.) If everything is normal, keep on keepin on. If something looks funky, back off (don't stop unless it's REALLY funky) and retest in a few more months. I'll bet a couple sats you're not 1 of the few percent of people who develop problems.
Source: the biochemistry text I teach from, and lots of time spent on PubMed