There is another thread going that is similar. I have run gh in the past and took off 7-8yrs. I recently started a year ago at 2ius a day and worked up to 3.3. I pulled several blood panels in the last year. I had an increase in rbc and heart rate. I usually donate blood 2-3 months to help but recently took 2 months off of gh and jumped right to 3.3 ius a day. My Feb blood work was high in H &H and RBC. I dropped gh and lowered t from 300 to 200 a week.