The math around pharmakinetics of Ozempic/semiglutide (and many drugs in fact) is fun from a mathematics standpoint and not too hard to understand.
Basically it has a 7 day half life, so they dose it every 7 days. So each week the amount in your blood right after an injection is : 1, 1.5,1.75.... approaching 2. Which means after about a month you reach max dose and it naturally levels off. The curve is basically logarithmic if you did the math though.
Its a nice little intro to finite infinite series, a fun topic IMO.