What is the optimal Rapamycin blood level and when do you measure it? Last day, first day or mid week from the day you take it?
Nobody knows that yet.
Keep in mind this might depend on other medical conditions that you have so if at all possible it’s usually best to have an MD help with initial dosing and following labs that rapamycin can affect (plt, hct, wbc).
I think the best you can do is pick a target from a study that showed minimal side effects and try to match the blood level in the study. Your dose may be different than study subjects to match the same blood level due to a variety of factors like absorption, meal content if taken with food, grape fruit juice, etc.
There is definitely a sweet spot where people tend to gravitate that generates tolerable side effects (acne, mouth sores etc). Usually people start out very low and end up in the range of 0.1mg / kg once a week but some go as high as 0.15 mg / kg once a week.
There is a recent paper reporting side effects in humans taking various dose and dosing regimens that might be interesting for you to read if you haven’t already.