Hello Patrick.
I start checking Hemoglobin/Hematocrit levels immediately upon starting TRT. I check at 6, 12, 24 weeks and once testosterone levels are at desired range, every 6 months. I find that the Hb/Hct levels will change within the 6-8 week window. I aim to keep the Hb levels below 15 and do not recommend donating blood as a regular method to maintain a Hb window. In my mind, if regular phelobotomy is being used, then the testosterone dose should be lowered. Also, I find that phlebotomy centers do not accept blood if the patients are on TRT. I use blood dontation in an isolated therapeutic manner when it is available and necessary.
That being said, there are a myriad of ways to practice TRT. There is NO ONE correct method and a wide range of practitioner preferences, even within the like minds that participate in the SSRP. Ultimately, it is about good patient outcomes and safety and there are a lot of ways to reach that. More of those details can be found in the Hormone Foundations and Hormone Mastery courses. I highly recommend them.
Hope that helps,
Abid