Help please

I initially started on 25 units through brightmed 0.25ml weekly/1mg I found a new company called Nimbus they sent my prescription which states “semaglutide 2.5mg” but stating to take 20 units which means it’s double correct? The wording on all of this confuses me so bad, that I sent an email thinking I was getting a decrease from what I’m already on. Is 20 units of 2.5mg enough to start noticing a difference with? They said after 2 weeks of doing 20 units on 2.5 that I can increase to 30 units