Rapamycin and Skin Abscess infection vulnerability

I started Rapamycin in March 2024. I began with I mg weekly with Pomello juice and moved to 2 mg shortly. I only had one side effect which was one sore in my mouth, which I took at least as a sign the Biocon med I bought in India was effective but had no side effects since. I’ve also been on Metformin, Acarbose and Dapagliflozin which resulted in welcome weight loss helping my metabolic syndrome (but not obese and otherwise pretty healthy for 64 years old)

anyway, I recently bumped the Rapa to 3 mg weekly with Pomelo juice (basically GFJ) I live in a tropical humid place and have commonly had problems with Prickly heat which I unwisely often scratch the pussy bumps.

But for the first time one of those bumps became a painful abscess in the middle of my back which I could feel deep in the nerves like shingles pain and got a few days of fever and chills, and erupted in two more deep abscesses under my arm and in front of my ear. Just got out of a day in the hospital after surgery and docs have sent tissue for tests to ensure not antibiotic resistant.
As soon as I realized I was infected and taking antibiotics I stopped the Rapa. the first Abscess showed signs of being necrotic
I don’t know how much of the infection vulnerability is due to circumstance and random and how much to blame on Rapa.
Tentatively the plan is to stay off rapa until Abscesses are healed. Wound treatment is ongoing (fevers stopped, still on antipbiotics and painkillers) and later resume without the Pomelo/GFJ as it would seem to add a unknown multiplier.
Sharing here in case there is insight I’m missing. This maybe side effect certainly seems more intense and dangerous than mouth sores but correlation isn’t for sure causation so collecting impressions now
Thanks for your reading and consideration


I hope you are feeling better.

If pomelo is like GFJ, it can result in up to ~3.5 fold increases bioavailability and even higher increases in total exposure as it decreases clearance rate. A one week dosing schedule may not prevent accumulation if in your case the t1/2 of rapa is much greater than 60 hours, which I suspect may have happened from the information you have given. There is a large baseline variability between adult individuals in rapa kinetics in any case. In patients treated with immunosuppressive doses, “The most common dermatologic side effects, each of which occurred in over half of patients, were oral ulceration and acneiform eruptions (Table 1). Oral ulcers appeared as discrete mucosal aphthae. Acne-like lesions were erythematous, inflammatory papules and nodules on the scalp, face, and back. Oral ulcers appeared as discrete mucosal aphthae.” It is hard to comment whether or not you may have been a bit immunosuppressed without more data, but if you are under medical care and healing, probably not at this time.

My story here on finding my personalized “rapamycin dose.”

I decided that for me, if aphthous ulcers occurred, they might be related to rapamycin induced immune modulation, so that became one of my “dose-limiting events” that is - if I experienced it, time to back off on the dose and/or frequency. I have experienced them every couple of years since childhood and I find them extremely highly very totally annoying.

It has taken me about a year to get to a reasonable dose of rapamycin without discernible side effects. I started on rapamycin about a year and a half ago. 1mg/week. After a month I experienced an extremely painful aphthous ulcer. I stopped rapamycin until it fully cleared, which took almost a month, highly unusual for stomatitis. I restarted rapamycin 1 mg every two weeks. Good for three months, same event as above, same place. Waited a few weeks to clear, and restarted rapamycin at 1 mg every three weeks. No problems, so about three months ago I upped the dose to 2 mg, but not the frequency, which is still every three weeks. So far so good. I may get trough pre-dose blood level in six months to check if there is any drug accumulation, which I very much doubt at this frequency and lack of adverse events. If good - up the dose to 3 mg every three weeks, and go back down in dose if any aphthous ulcers, or other events possibly related to rapamycin emerge.

My impression from the literature and personal experience is that it may be good for some people like myself to assure enough time to fully clear the rapamycin before another dose. That also fits with my hormetic, anti-fragile bias towards drug dosing for certain conditions. I pay close attention to my body responses. Even if I don’t “fit in” the norm, I adjust since there is no data in humans on the risk/benefit or even dose/frequency of rapamycin used in pulse doses for longevity until we get some longer RCTs.

Thank you for sharing your experience as it has some similarities with mine, though in a much less dramatic way. I hope you are over the worst!


Thanks for your helpful detailed reply. I do seem to be over the worst. I still want to continue with Rapa going forward but will eliminated the GFJ/Pomello element as presenting too many unknowns and confounding elements. Assuming Rapa stays cheap in India where I often visit, the cost isn’t a huge factor so my predilection for efficiency and conservation of resources is contradicted my my suffering and hospital bill. lesson learned as the decreasing clearance rate is an additional issue beyond the dose multiplication.
Life (hopefully) and learn so hope sharing here may benefit some choices in the future.


It’s also occurring to me that I’ve heard SGLT-2 inhibitors, and I’m taking one, can increase chances of necrotizing fasciitis (example being Fournier’s gangrene), an infection that could be exacerbated by the reduced immunity from the Rapa, and this could have led to the deep infected abscesses. While, due to lack of fever and reduced pain, I feel I’m out of the deepest woods, I think I’ll discontinue the Dapaglifozin until healed as well, and forgo the GFJ/Pomelo forever

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Yes - we’ve discussed this risk in these threads/posts, it seems that there may (on average) be a slightly higher risk than getting hit by lightning. However, if you’re already getting some skin infections I would definitely pause the SGLT2 inhibitor out of an abundance of caution.

Risk of getting hit by lightning:

In the United States, a person has an estimated 1:10,000-lifetime risk of being struck by lightning.
Lightning Injuries - StatPearls - NCBI Bookshelf


I had been getting an infected sebaceous cyst every year for three years. The last one was 2 years ago while I was on Rapamycin. For the first two, I had minor surgery to address them and for the last one, I used antibiotics. Antibiotics are definitely the least painful and inconvenient method.

Fortunately, I haven’t had any this year and I hope that I am healthy enough now that I won’t get any in the future!

Whenever you have an infection, surgery, or wound it is best to stop taking Rapamycin and start taking AKG as it aids in wound healing (but not for infections).


Indeed, I saw that. now combine that risk with taking Rapamycin reducing immune response at an unknown level because of being combined with a big large whole polmello weekly the night before and day of intake .

I think it adds up to an unknown risk combined with my poor hygiene about it. IT is indeed unknown how much of a role, of any these three confounding factors played in this thing that happened after years of having heat rash problems in the tropics but thought to share as a data point in the future. I was a big fan of the GFJ rapa symbiosis for economy and conservation but now suspect the wild card of all this combined is not worth it

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Don’t you just press it and get rid of it? I have been getting them before taking rapamycin. Had them once only in the last 6 months during rapamycin. I normally just go into a hot spa and heat my body up then squeeze if off in the shower. That usually works. My doctor offered to take it off for me too. Like a big acne. Normally if I leave it alone, it will disappear after a few weeks.

I wish I could lance them to get rid of them, but they were too deep and infected. They needed to be cut open and drained. The last time, the antibiotics worked.

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It is nice to know there is someone else on the 21 day cycle. I also track my bloods every week. What I think happens is that it further reduces WBC, but mine was particularly low anyway. My last result was 2.3 (billion cells per litre) which is not the lowest it has been. However, my last Rapamcyin was slightly after that and my next blood draw is tomorrow.

I think my protocol increases the innate ability of cells to use cytosolic ROS to fight off infection through a form of inflammatory response. I think this particular helps to clear off warts and the like. I am, however, not sure exactly what drives down my WBC (other than Rapamycin). As I am not getting infections that much and it has been like this for over 2 years I am not particularly worried.

If you have an epidermal inclusion cyst (the formal medical terminology), get it settled down then have a physician who does skin surgery (I do these) do an elliptical excision removing the cyst … then you no longer have the cyst that can get recurrently infected.
This was bread and butter family medicine when I did my training, but now you have to find someone who has some basic skin surgery skills.


Yes, I’ve had two surgeries to remove 2 infected sebaceous cysts in the past. It wasn’t terrible. But I’d be happy to avoid them in the future.

Generally, when infected, they aren’t removed, they are simply lanced and drained, but the cyst remains. Once settled down and not infected, there is an elective removal of the cyst and then, there is nothing remaining that can result in recurring infection.


Yes. Exactly. That’s what my doctors did.

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Also noting to add to wild card level of rapa activation by eating pomelos, it turns out that different varieties have wildly different levels of furanocoumarins. Unless one can identify varieties of Pomelo

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The SGLT2’s are associated with Fournier’s specifically, not nec fasc in general.


True but there’s basically no data about how SGLT-2 inhibitors would be interacting with Rapa and suppressed MTOR, which makes it worthwhile sharing a bit of anecdotal story to see if there’s any patterns out there. I plan to return to both and haven’t stopped my SGLT-2 intake