So I’m wondering given what MK said in his response to your question if it might be beneficial for you to stop the Rapa now until that January blood work up to let the HGH really give a boost to your thymus.
Think of it as now taking the brakes off for the last couple of months.
I’d be mightily surprised if you noticed loss of Rapa benefits for two months. (Even if you did that would be an interesting data point for you and I’m sure you’d get the benefits straight back again after a few weeks).
Would be interested to know what you decide to do.
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Hey Roberto… 
That is exactly what I plan… no rapamycin until the end of January… basically 3 full months.
Contiuing HGH… at 3.3 iu daily and then end of January 2026 doing a full thymus scan and new T-cell numbers reading… DEXA bone density and fat- adipose tissue reading, Coronary Calcium Scan, GlycanAge Inflammation score, and DNA methylation reading. With a full blood panel review.
Start off the new year with a full work up.
My medical university is changing health insurance, so I can do all of these tests at once with the new provider. I just checked with them.
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We need to be very skeptical and cautious when using mice as a model for human organ/tissue regeneration. Mice can quickly heal very large wounds, can regenerate amputated digits, regrow damaged cartilage, and exhibit a host of regenerative capacities that humans do not possess.
What this study actually shows is that high-dose rapamycin damages the thymus (something seen in numerous older studies in mice and primates), but that mice then mount a regenerative response that increases thymic mass beyond baseline.
We don’t know if humans respond in a similar way. It is entirely possible, even likely, that we don’t exhibit a similar regenerative response, and that high-dose rapamycin is toxic to thymocytes without stimulating regrowth.
With that said, I doubt that the low dose intermittent dosing that most people are using will atrophy the thymus the way that high doses do in mice. But higher doses or continuous doses likely would. I highly doubt that rapamycin is a route towards thymic regeneration in humans.
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Yes - we always need to be cautious. At the same time the record for rapamycin at improving function of aging organs has been demonstrated in many different studies, and has shown cardiac benefits in dogs too.
See this thread for past related studies: Can Rapamycin repair your organs and therefore reverse aging?
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Sure. I’m not speaking to benefits observed in other tissues, only the purported stimulation of thymic regeneration.
I’m convinced of the value of rapamycin for many other longevity purposes, just not thymic regeneration for the reasons mentioned.
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For the thymus regeneration potential, I dont see why it wouldnt be the case in human. Especially since we have an effect as “immune reset”. So for now personally I will use 6mg rapamune per 6 weeks or once a month.
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I am also switching from weekly to monthly Rapamycin dosing. The last time I had blood drawn, my white cell count was low. I assume the T cell count CD4 or whatever was also low.
I wonder if there would be any value in a group of us testing CD4 a year from now after following a strict Rapamycin dosage schedule. This is routinely tested in HIV patients, but we might determine a bit about Rapamycin dosing. We would need a weekly group, every other week group, and a monthly group. We might also have high and low dose people in each group. A good age adjusted CD4 hints that the thymus is working well.
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As I have stated previously let this place be a registry. We all feed the data, biomarkers, labs and regimen. Let AI do the rest! Or, may be let AI take the guided lead!
I am sure there are database experts in here besides healthcare ppl.
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" low-dose rapamycin (1 mg/kg per day for three days)"
Huh? 1mg/kg constitutes a low dose?
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So the fact that females were one commonly excluded means that it henceforth okay to exclude males?
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@msmccor100, sorry if my comment was confusing.
I wasn’t trying to take a stance on the current state of gender equality in science. However, I was trying to tease my forum friend. FYI, the kissy face emoji often denotes playfulness.
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These are rodent medicine numbers.
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Yes - and 1mg/kg IP injection is actually on the lower dosing schedule for the mammals. Here is the range:
- Mouse — 20 mg/kg/day i.p. (daily) in Nf1 mutant mice. Dose–response study measured blood/brain levels and pathway readouts at 0, 2, 5, and 20 mg/kg/day i.p.; 20 mg/kg/day suppressed AKT activation that rebounded at 5 mg/kg/day.
- Mouse — 8 mg/kg/day i.p. (daily) in Ndufs4−/− mitochondrial disease model. Repeated i.p. 8 mg/kg/day improved survival and disease metrics; same group details PK/PD and weight effects.
- Mouse — 8 mg/kg i.p. schedules (M–F or weekly) in Tsc2 tumor models. Compared 8 mg/kg i.p. regimens: M–F for 4 weeks, weekly, and hybrids; all injection routes.
- Mouse — 10 mg/kg i.p. (single-day) in BTBR behavioral model. Single 10 mg/kg i.p. dose used to test sociability/stereotypy outcomes.
- Rat — 10 mg/kg i.p. (single dose) in metabolic/behavior study. 10 mg/kg i.p. rapamycin administered to rats; outcomes measured days to weeks later.
- Rat — 20 mg/kg i.v. (single bolus) acute-tox comparison. Head-to-head acute-tox study gave rats a single 20 mg/kg intravenous dose of sirolimus; survival, hematology, organ histology assessed at 5 and 14 days.
Takeaway
- The highest repeated injection dose in mice I can document is 20 mg/kg/day i.p. (Nf1 model).
- Frequently used “high” repeated dosing is 8 mg/kg/day i.p. in disease models (e.g., Ndufs4−/−).
- In rats, clearly reported injections include 10 mg/kg i.p. (single dose) and 20 mg/kg i.v. (single bolus) in acute-tox work.
Here are the highest documented injection doses of Rapamycin (sirolimus) in mammals, route = injection only, with direct links:
• Mouse — 20 mg/kg/day i.p. (5 days/week × 2 weeks) in an NF1-mutant glioma model.
Link: https://pmc.ncbi.nlm.nih.gov/articles/PMC3857701/ 
• Mouse — 8 mg/kg/day i.p. (daily) in the Ndufs4−/− mitochondrial disease (Leigh Syndrome) model.
Link: https://pmc.ncbi.nlm.nih.gov/articles/PMC4055856/ 
• Mouse — 8 mg/kg/day i.p. (daily) more broadly referenced in dosing-response/lifespan review.
Link: https://pmc.ncbi.nlm.nih.gov/articles/PMC8190242/ 
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Sorry, I’m slow.
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I was glad to see the effect of Rapamycin on the thymus gland in the study, but what I really need is to heal my adrenal glands. I make almost no cortisol. I’ve been taking Rapamycin (6 mgs per week in one dose) for over 2 years, but haven’t noticed any improvement, so I am switching to Everolimus.
I would appreciate hearing from anyone who knows whether there is hope for adrenal healing with either drug.
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any suggestions re: where to get rapamycin?
Hehe, unfortunately the real reasons are pretty boring:
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If you only use male mice, reviewers and maybe Editors will complain. There’s a big drive in publication now to strive for more gender/sex equality. So using female mice basically neutralises that criticism.
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Using two sexes of mice won’t help you publish in a better journal. Journals care much more about novelty (new ideas)
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Using two sexes of mice, and making a male/female comparison more than doubles the resources you need. So in the study they had 13 experimental groups. If you add another sex, and you want to do comparisons between them, you’d probably need 1.5x more animals because the more comparison you make, the more mice you would need to achieve statistical significance.
So in my lab we’ve also moved to using mostly female mice for most experiments, to satisfy journal policies and avoid this criticism from reviewers.
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Do you use ovariectimized female mice?
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Nope. Just regular B6, FVB or sometimes BALB/c. Guys like Rich Miller are 100% correct when they say it’s silly how most aging research is done on B6. But - you won’t get your papers rejected for using B6 mice, and you probably will face extra challenges if you use “non-standard” mice, without a really good justification. (I will say I’m not really an “aging” researcher, but we do try to incorporate some aspects into our studies)
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