#1

For Sirolimus users enhancing their absorption with grapefruit juice, be advised that differences were found between canned and frozen. This study found frozen magnified the effect at a rate of 3.5–meaning 2 pills = 7 when downed the juice made from the frozen concentrate form. in the absence of a particular brand endorsement, I prefer to make my own from fresh grapefruits.

https://www.uchicagomedicine.org/forefront/news/grapefruit-juice-lets-patients-take-lower-dose-of-cancer-drug

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Grapefruit vs pomelo while taking rapamycin?
About GrapeFruit
#2

Yes - Also - some additional reading if you are considering grapefruit juice with rapamycin:

Here: Improve Bioavailability of Rapamycin (2)

Here: Rapamycin and Grapefruit Juice

Here: Grapefruit interaction with longevity meds?

Here: Rapamycin Interactions with Other Food, Drinks, Supplements and Drugs

Here: Ketoconazole timing for enhanced Rapamycin absorption

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#3

By dumb luck - I found and use the Red Grapefruit I get at Walmart - costs about a buck each.

I cut it into quarters and hand squeeze (literally) into a glass using a strainer. I get about 5 fluid ounces and that alone downed with my rapamycin dose gives me a 6-7x’s increase. I use Labcorp and it seems consistent with fresh Red Grapefruit. Plus it doesn’t taste too bad - I am not a GFJ fan. . Will do my next test in April.

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#4

Does anyone know of advantages to squeezing the juice, rather than simply eating the whole of the fruit?

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#5

FWIW

I eat the entire fruit, 45 minutes to 1 hours before.

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#6

I was doing 6 mg with GFJ. Now I think that’s a bit much as I went to my dermatologist last evening and she said the rash on my neck appeared to be autoimmune related. She asked if I was taking any chemicals that may have caused this… Also, the sebaceous hyperplasia has been linked to transplant patients taking tacrolimus. So I may have shutdown too much of my MTOR systems.

So, I’m going back to 3 mg + GFJ weekly and forgoing the hair tonic for now. I’ll re-evaluate later.

Also, the beta-alanine was making things worse and I should cut it out. Itching and rashes are signs of inflammation and probably not healthy.

Too much of a good thing… At least now I know my limits and that I shouldn’t go beyond 6 mg + GFJ bi-weekly.

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#7

Why does it seem that no one uses quercetin, a potent competitive inhibitor of CYP3A4, for enhanced bioavailability? GFJ seems a bit random by comparison.

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#8

Please post any good research papers you have seen on this

#9

Effects of quercetin on the bioavailability of doxorubicin in rats: Role of CYP3A4 and P-gp inhibition by quercetin

From paper

“Quercetin inhibited CYP3A4 enzyme activity in a concentration-dependent manner with a 50% inhibition concentration (IC(50)) of 1.97 μM. In addition, quercetin significantly enhanced the intracellular accumulation of rhodamine-123 in MCF-7/ADR cells overexpressing P-gp.”

Would you want to post this as a separate thread?

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#10

I read it here:

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#11

I am using Naringin

I know that it is supposedly only one of the flavonoids in GFJ but the dose is the same each time, and I just take 1 capsule an hour before Sirolimus

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#12

Yes - I like the standardized dosing as you mention. Do we have any idea on the actual effect on blood sirolimus levels? Have you done any testing after dosing?

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#13

I have no clue, I have the desire to learn, but lack the motivation to actually follow through. :grinning:

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#14

I read somewhere that white GFJ is preferable (in terms of efficacy) to ruby red. Has anyone heard this?

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#15

Yes, I looked up the Florida citrus report, and the white more bitter Grapefruit has more of the essential flavonoids

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#16

I’m not sure - here is one study suggesting similar outcomes with both:

and another article/paper:

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#17

Interesting, white grapefruit is yucky anyway

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#18

Yep. I get 6xs to 7xs increase of my rapamycin dose on Red Grapefruit. Goes down smooth-ish.

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#19

Red/pink or yellow - Duncan (yellow) apparently has the highest levels of most of the four furocoumarins .
Variation of bioactive furocoumarins and flavonoids in different varieties of grapefruits and pummelo | SpringerLink

Full Paper / PDF Below:

s00217-007-0654-4.pdf (483.1 KB)

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What types of grapefruit juice increase Rapamycin levels the most?
#20

Forget that grapefruit juice deal - crap ! Do ketoconazole instead as it is more effective and u know what u are getting.

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