Dose - does it matter?

Apologies for beating my usual drum, but I think the target should be to ensure that there is normal stem cell production (and immune system*) for a proportion of the time. Hence a higher dose less frequently is more likely to be useful than a lower dose more frequently.

*Obviously if someone is taking rapamycin to stop transplant rejection they need to take a continual dose.

What we don’t know is what doses have what effects on stem cells, but that is research that we collectively can do simply by considering a visible aspect of stem cell production viz nail growth.


I am very curious about how to keep weight in mind when figuring out our individual doses.

I realize no one knows at this point, but perhaps we (and when I say we, I mean, all of you) can put together a rough guide?

If we accept the premise that the average person should consider weekly doses at 6mg, which is what my doc prescribed for me, how much does this average person weigh?

What might we consider adding or subtracting for each, let’s say, 10-20 pound-ish difference?

I considered putting this in the questions for Matt K, but I imagine he wants to stay far away from dosing recommendations for anyone but himself?

My biggest question might be where did that 6 mg come from and is there any reason to rely on it.
Good question for Matt K.

If you feel it’s appropriate, I’ll move my post on over there…

Also, took 6mg for the second time yesterday. My tiny arm rash that started to go away yesterday is back, and now it’s itchy. I also have a red spot on my knee the size of a quarter that itches.

It’s potentially a bite, but I’m guessing it’s from the rapa because it’s in unison with my arm (that showed up after my first 6mg dose). It’s not a huge deal at this time, but would this mean my dose is potentially too high for me? Or is there not much of a correlation?

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It interesting, sometimes I have had rashes that are not at all correlated to dose (ie. just happened randomly at a lower dose but never again at higher dose) and some I had consistently (under my Fitbit) at higher doses but then I stopped wearing the Fitbit and had no more rashes.

So… as with many things, “it depends”…


The “which came first the chicken or the egg conundrum” :slight_smile:

Or the correlation is not causation bias.

I’ve had “things” happen after starting “something” new. When that happens I try to go back in my mind ask myself if I’ve ever had this “thing” before? If I did have it before was I taking the new “something” then ? Usually I was not taking the new something and it becomes obvious that this “thing” is not related to my new “something” … I often become hyper aware of changes when I change or add to my routines and this can drive doubt and increase questions.


It’s so true and hard to know!

Last night I shared with my husband the fascinating placebo effects I read about here where a few people in a study who were on placebo had rashes, mouth ulcers etc. To your point, he said it could be placebo effect, or sometimes people just randomly get these things and maybe it was going to happen to them anyway. Impossible to be sure!

I started zetia last week and finally looked up the potential side effects (because I was sure I gained weight on rapa because I look practically pregnant-ok, maybe I’m exaggerating- and forced myself to get on the scale and was beyond shocked I hadn’t, so I guess it’s bloating and wanted to see if it could be related to zetia).

Interestingly, I see zetia can potentially cause rashes! It can also cause fatigue or even mess with your thyroid (I’m hypo). I see now lithium can potentially mess with thyroid too, and I just started taking 1mg, but perhaps that pertains to high doses. So many balls in the air!

So, the rashes are probably from rapa, but possibly not! Also, I felt fantastic my first week of 1mg of rapa and have not felt great the last week on a higher dose, but that could be from rapa, or zetia, or, as you say, it could be random. I do feel strange, but one thing I notice is that even though I don’t like how I’ve felt, I have significantly more focus (ADD issues!). I haven’t searched this forum yet to see if rapa helping ADD is a thing. I started some other supplements but have stopped so I can try to tease out all of these things.


Here is an MSDS sheet for Rapamycin. This sheet has some interesting information that mostly pertains to manufacturing protocols but…

Go to page 4 and you will see there there is no LD50 listed other than it was tested up to 2,500mg per kg in mice and no fatalities :slight_smile: With this type of extreme dose, they typically stop increasing it and call it a day.

In humans that mouse dose would translate into 200mg/kg, for me at 70kg that would be a dose of 14,000mg! so we are a long way from any serious OD complications.

Dose conversion information.


Where do you see that Ezetimibe worsens thyroid function? I read your post so I had to google it and found this, where it shows it could actually improve thyroid.

Thyroid Hormone Status in Sitosterolemia is Modified by Ezetimibe - PMC (


Thx for looking it up!

Oh, I was simple using the fancy medical terminology of ‘it messes with’, meaning it could change it (in this case, for the better, fingers crossed!).

I now realize I need test a little more often to ensure my t3/t4 dose doesn’t become too high.

If I get so lucky and have an improvement, it will also prevent me from inaccurately attributing it to rapal!

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The reason I wanted to look into it is because I also take Ezetimibe and have a slight thyroid issue (poor converter of T4 to T3) so I wanted to make sure I wasn’t harming myself. Looks like it’s all good.

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