Bioavailability of Rapamycin From Compounding Pharmacy

This is an important consideration with regard to compounding pharmacies. TeslaDoc (below), a doctor who both uses rapamycin personally and prescribes rapamycin to his patients) only talks about rapamycin from compounding pharmacies in the tweets below, vs. Pfizer rapamune (the branded version of rapamycin from the original manufacturer). Most people don’t use either of these options - instead we use generic versions from well-known Indian manufacturers like Zydus, Dr. Reddy’s, Biocon, etc. These don’t seem to have the same level of bioavailability problem that the compounding pharmacy capsules seem to have (at least in some cases). You can take a blood sirolimus test after you take rapamycin to verify that its getting into your bloodstream.

Extremely important, good for sharing.

n=1, flying blind without sirolimus blood tests

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Missing info here is how the dose was taken; Empty stomach, with food, with fat, with grapefruit juice, etc.
This is why I choose to use the higher dosing with grapefruit juice. Even though I don’t measure rapamycin directly, I know from my blood tests that rapamycin is having an effect on my biological age markers. Plus, I am even more assured that my rapamycin from India is good stuff.


You are a long time user, high doser and have experienced side effects (and have labs), so you know there’s an actual blood mediated signal. Others taking low dose without any symptoms, like this example, might not have any absorption.

This is concerning. The level shouldn’t be zero.
Makes me wonder about Tailor Made even though he didn’t specify.
Might have to look elsewhere now.

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Does anyone here use the compounded transdermal cream offered by

Yes, it is suspicious as even a very low-dose skin application of rapamycin shows up in the blood according to this article:
Topical rapamycin reduces markers of senescence and aging in human skin: an exploratory, prospective, randomized trial

Where are you getting it?
Might have to switch.

Was the capsule acid resistant? I tweeted the question to Tesla Doc.

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I am never successful in getting a response when I reply to Twitter posts. Here is what I tweeted to Tesla Doc regarding the zero level of sirolimus found in his patients blood test:

Unless the capsule was acid resistant, which it probably wasnt unless you ordered it to be, then the sirolimus was most likely broken down before it reached the lower intestine. Did anyone ask the pharmacist that question?

I thought the question was relevant and important. Whats the secret to getting an answer.

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If you have 650 followers on Twitter, would you answer an embarrassing question

from a reader with no followers?

Going to guess regular capsules. Enteric coated would be a special ask.

Even if enteric, it might confound the 2hr level (still hasn’t released), but “should” capture 48 hrs… But it’s VERY possible its below the “<2 ng/ml” low threshold. Where I am, the low threshold is 2 ng/mL. So a reading less than 2, is just reported as less than 2, no actual value…you have no idea if 0 or 1.99.

This is most likely inter person variation (gastro, intestinal and liver enzymes, etc) , a widely studied and reported COMMON outcome in sirolimus trials. We’ve referenced this in several places on this forum. In clinical studies, they monitor each patient individually, adjust dose.

Both pharma grade (eg Rapamune) oral solution and tablets show very similar absorption kinetics, namely, undergoing similar 1st pass kinetics.

So I guess the bottom line is that we all have to check our individual levels.

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Agreed. So we don’t really know whether the undetected sirolimus was a result of inter person differences, or lower absorption of powder vs tablets, or a combination of both. Sirolimus might have been present and simply didn’t reach the threshold.

Could be several possibilities. The most plausible may be individual variability but we can’t rule out fraud on the part of the supplier, whoever it may be.
I believe that there’s a lab that will do an analysis of pills/ capsules and tell you exactly what’s in it. If you find out that the capsules aren’t actually rapamycin then at least you know that you’re not the problem, so to speak.

FWIW, A third-party assay would cost more than purchasimg Pfizer RAPAMUNE® (sirolimus) from overseas. Last time I looked several weeks ago RAPAMUNE® can be purchased for just under $400.00 per box of 100

Testing would cost more than $400.00

Very true. Where can you get it for that price?

I was thinking about the person who got the blood level of zero. I’d be suspicious about the supplier but I would also wonder if it was something to do with my system. If I’m not absorbing it or rapidly metabolizing it, then Pfizer won’t help, but suppose it’s just placebo pills then that’s a different story.

Postings on this forum listed a person/company selling

See link below;

Looks legit.
I’m also going to check with the pharmacy that Alan G. uses.

Sent an email several weeks ago, was quoted just under $400.00 shipped.

I have been using the Dr.D brand 2mg tablets from a local ACME pharmacy some insurance some I pay. Posted this below in another thread.

“06/18/2022 I purchased 24 2mg tablets, Dr D brand, with an online coupon for $110.33 at a Local ACME Pharmacy”