Desertshores, you may not have seen my post in the other thread regarding optimizing peak dose (Cmax), so Iāll post it for you here.
Taking sirolimus with high-fat food has opposite effects on the Cmax (peak dose in the blood), depending on whether youāre taking the Oral Solution or Tablets.
"Food effects: In 22 healthy volunteers receiving Rapamune Oral Solution, a high-fat meal (861.8 kcal, 54.9% kcal from fat) altered the bioavailability characteristics of sirolimus. Compared with fasting, a 34% decrease in the peak blood sirolimus concentration (Cmax), a 3.5-fold increase in the time-to-peak concentration (tmax), and a 35% increase in total exposure (AUC) was observed.
After administration of Rapamune Tablets and a high-fat meal in 24 healthy volunteers, Cmax, tmax, and AUC showed increases of 65%, 32%, and 23%, respectively."
So, depending on whether youāre taking the Oral Solution or Tablets, taking it with fat will lower or increase the peak dose, respectively.
Regarding the source of the grapefruit juice, the authors of the research study actually found one of the store bought brands didnāt actually contain the active compounds which are necessary to result in the increased rapamycin absorption. From the article: āInterestingly, different grapefruit juice formulations appear to vary in inhibitory potency and therefore, in consultation with the Florida Department of Citrus, we employed a frozen concentrate product that was tested for furanocoumarin levels prior to delivery of each batch.ā
Just to take that variable out of the equation, I use actual grapefruits rather than relying on store-bought juice which may have different processing methods, pasteurization, etc.