I got my first cold sore right after starting rapamycin too, luckily I just got it this one time even though I went as high as 12mg with grapefruit juice (I weigh around 75-6kg). You could try increasing the dose a few times with more time between doses and see if that works. I’d keep some acyclovir creme ready in case you feel a cold sore coming up
3 Likes
Thank you for sharing your experience (12mg, wow! I thought anything above 7-10mg crosses into ‘transplant’ doses? But I guess it must be individual too. Update: oh I see, you mean 12mg if you count the juice in!)
Yeah, I’ve exhausted all my acyclovir supplies (pills and creme) since I started rapamycin! I normally store on those when I go to visit my family in Russia, since acyclovir is OTC there. I had about a year worth left, I thought! But it all melted within 2 months 
Luckily I’ve found a couple of Slavic online pharmacies in the US, which will sell Ukrainian and Russian acyclovir/penciclovir meds without prescription.
3 Likes
Thank you for this insight! I’m gonna go store on turmeric/ ashwagandha/ boswellia 
2 Likes
I did 12 mg with grapefruit juice equivalent to 36-40mg 
3 Likes
Do i recall correctly that cold sores were at or near the top of the list of self-reported side effects for our group? I reported about a 3-fold increase in incidence (labial) in an earlier survey for our group. I’m 190lb and had been taking a once weekly 2mg dose with grapefruit juice. The increased incidence occured a month or two after initiating Rapa. Not immediately. Now I take 2g of valacyclovir at the same time as the rapamycin but cannot report results yet. As discussed here by others, an increased incidence of labial cold sores might increase the risk of neurodegenerative disease based on various uncontrolled and cross-sectional reports. FWIW i have changed my dose to 4mg Rapa without grapefruit juice plus concomitant 2g valocyclivir. As an APO-e4/e3 genotype and with a rare seizure condition, having an increased risk of cold sores on this regimen will cause me to reduce the dose further, possibly to stop if it still increases my cold sore incidence.
4 Likes
Yes - mouth sores are by far the most common side effect people see - with 37% of our users reporting this issue at least once: Rapamycin User Poll / Survey - Please Respond - #3 by RapAdmin
Is it worth having the surveys collect separately canker and cold sore side effects?
1 Like
I can’t think of any significant benefits for that level of granularity on the side effects, but perhaps someone else can.
Cold sores and canker sores are very different. The former being a viral flare up and the latter… (we don’t know)
2 Likes
Ah yes - what we get with rapamycin is mostly just canker sores (apthous ulcers).
1 Like
“More than half of American adults have HSV-1. Around 30% of people who have oral herpes may experience recurrent outbreaks of cold sores.”
It really would be interesting if forum members who consistently get cold sores after taking rapamycin would get an HSV-1 test.
I would like to confirm my theory that this latent virus flares up when the immune system is suppressed by rapamycin.
3 Likes
Actually, on further review, you probably don’t need to take the test. If you have actual cold sores, not cankers, then you almost certainly have Herpes HSV-1 which flares up when you take rapamycin and temporarily suppresses the immune system. In this case, you will just have to tolerate it if you plan to keep taking rapamycin. If in doubt you can always take the test.
4 Likes
Interesting. I have been on a low dose of rapa (2mg/week) for nearly a year. Recently noticed a “cold sore” on my lower lip. Just as that one healed, one appeared on my upper lip. I used to get cold sores when younger but I reckon it must be 20 years since I had one!
Anyway I have had 4 weeks “off” rapa during December.
If the herpes returns early 2023 after I resume rapa then I can assume a connection.
2 Likes
Cold sores are usually located on the lip, OUTSIDE the mouth and are from Herpes virus. Canker sores, also known as aphthous ulcers, are located INSIDE the mouth, on mucous membranes. I have not had either of these from taking Rapa, but I do sometimes get small cysts inside my mouth.
2 Likes
Yes, cold sores can form inside the mouth, but it is much less common than when they form outside the mouth. It is estimated that only about 5-10% of cold sores form inside the mouth.
“No one knows what causes canker sores. They may be caused by a virus, maybe a form of allergic reaction, or may result from an auto-immune condition (meaning that the body has developed an immune reaction against its own tissue”
IMO: Whichever is the case, mouth or lip sores after taking rapamycin are most likely caused by a depression of the immune system.
I am trying to figure out why, most?, people taking rapamycin don’t get them.
1 Like
I have found red and near infrared light help prevent cold sores. You might try a 60 day trial from Platinum or Mido red light or one of those companies and expose your face for 10 minutes a day and see if it helps minimise the outbreaks.
2 Likes
these are just small mucokeles
I have used this product, though it was before begininng rapa. It has cured all cold sores. I have not had one reoccurance of cold sores with or without rapa:
Its a immune modulator / support, but targets Herpes virus that causes cold sores.
https://enzolyticstherapeutics.com/
It is sold in bulgaria under a different name and has this data of Herpes teting:
Its been great for me - you may want to check it out
4 Likes
Is it sold in Bulgaria under Enzoimmune Active name? Do you have spelling of it in Cyrillic (Bulgarian alphabet)?
im sorry - i dont know that. however yes it is sold as “enzoimmunue active”
perhaps if you go to the website it will be in bulgarian for you? I am in U.S. so its in English.