Been some discussion on Grapefruit juice and pro hormones. A study was posted by right hook saying that grapefruit juice, due to it having naringen, could actually inhibit the conversion process and therefore do no good for you. Anyone on a pro hormone willing to try this? Take 4-8 ounces of grapefruit juice with your steroid/ pro hormone. Maybe even take a slightly lower dose. See what happens after a week of it? Nothing too drastic. Don't wanna fuck up anyone's cycle. Anyone down?

Here's the article in question-


"Long Answer - While grapefruit juice does effectively inhibit CYP450 enzymes, it also contains a large amount of naringenin (22). Naringenin is extremely detrimental to a critical enzyme known as 17beta- hydroxysteroid dehydrogenase (17β-HSD) type 5. 17β-HSD type 5 is perhaps the most critical enzyme in the process of prohormone conversions. This enzyme completes the conversion of all these prohormones to more powerful metabolites (diols and testosterones), which is what makes them effective muscle builders.



Naringenin has shown that it can inhibit up to 50% of this enzyme when plasma levels reach only 2.4μM. To give you an idea of just how little grapefruit juice you need to consume to reach these plasma levels, you need only 24 ounces to reach plasma levels of 6μM. If you consumed grapefruit juice every day, plasma levels of naringenin would reach well over 20μM (22). With plasma levels of 20μM, 17β-HSD would be inhibited well over 70%. This would leave you with a significantly less powerful dione based prohormone (after conversion via 3β-HSD). The below chart shows increasing levels of 17β-HSD inhibition, based on plasma levels of 20μM for each compound, naringenin is the red bar. Naringenin is also one of the few compounds in this chart that we can actually reach high plasma levels by food consumption (grapefruit juice). It should be noted that AKR1C3 is another name for 17β-HSD type 5.

So the next time you see someone recommend you try and increase prohormone bioavailability with grapefruit juice?please think again.





Reference:
Skarydov?, Lucie et al. ?AKR1C3 as a Potential Target for the Inhibitory Effect of Dietary Flavonoids.? Chemico-Biological Interactions 178.1-3 (2009): 138?144."