Using Parsley to increase Rapamycin Blood Levels

Saw this post by Clark Sims yesterday, and I was not familiar with the parsley effect on blood sirolimus / rapamycin levels.

And the research paper on this topic:

Parsley, a commonly consumed food, affects the level of an important drug (rapamycin) in a renal transplant recipient: A case report


The juice, which contained about 30 g of parsley, was consumed by the patient for 7 days.

That is a lot of parsley!

Apigenin, the dominant type of flavonoid in parsley, has been reported to possess the ability to inhibit CYP3A4 and P-gp and thus, it may be involved in drug interactions

CYP3A4 is also inhibited by grapefruit.

The sirolimus concentration increase from all that daily parsley:


So - somewhere in the range of 4X to 7X the blood sirolimus levels with 30grams of parsley… wow, quite a difference…

immunosuppressive treatment of the patient was under control with sirolimus 1.5 mg twice daily, … In July 2020 at an out-patient follow-up visit, the patient’s blood level of sirolimus (14.8 ng/ml) was seen to be high. Previous blood sirolimus levels ranged from 2 ng/ml to 4 ng/ml. …


and some recipes and instructions:

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There were some other effects on lipids they said were associated with parsley consumption at these levels. Not good ones.

Also, this is a case report/observation. Not anything like a “study”. Does not mean the effects are not occurring, but pretty thin evidence. Seems to me with all the other variables in rapa dosing this is not the best option.

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Yes - and many unknowns - the difference between dried vs. fresh parsley, dose response, etc…

I think we need to be a little careful here. Rapamycin is an actual drug with very real effects and we shouldn’t be too cavalier with it. It can inhibit the innate immune system, and the Kaeberlein study showed that at high doses the female mice got hematologic malignancies. It’s not like taking vitamin C and just jacking up the doses. It’s possible to get too much.
I’m a big believer and have been on it for 5 years, but I’d be careful just downing it with cytochrome inhibitors which may alter the benefit/risk ratio in the wrong direction.


As I have said/posted before…

Latin: “dosis sola facit venenum”

“only the dose makes the poison”

~ Paracelsus

“All things are poison, and nothing is without poison; the dosage alone makes it so a thing is not a poison.” ~ Paracelsus

We are all looking for the black cat in the darken room.

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I am taking dried parsley … daily 5g. Do you know the concentration difference between fresh and dried parsley? I think I read somewhere its around x8 more of apigenin in dried!

Also, I am now on 5mg Rapamune with those 5g of dried parsley … maybe its too much, any thought?

Would Apigenin supplements do the same thing? Seems like that’s what all this is pointing to. I do take daily Apigenin…