Rapamycin lowers testosterone?

I started rapamycin Dec 2020. Unfortunately, I didn’t do my first T test until the following May. Ignore the 2014 result, as it was unnaturally low due to stress and lack of fitness. I’m not on TRT or any hormones.


Here is another good comment from Charles Richardson on Bikman’s facebook post

“I read the study. It’s a review study, and it looks at the effect of rapamycin on transplant patients. That’s the primary use of rapamycin and that’s important because transplant patients take rapamycin daily and continuously. Taken continuously rapamycin inhibits the immune system, which is why it’s used in transplants to suppress rejection. People taking rapamycin for anti-aging or health enhancing purposes take it intermittently, once a week, or once every 10 days. Taken intermittently rapamycin actually improves the immune system. So any study of rapamycin with transplant patients may not (and probably doesn’t IMO) translate to people taking rapamycin intermittently. I’ve been taking rapamycin once a week for 3 years, just had my testosterone checked, and it’s fine. That’s N=1 of course! It’s probably a good idea when talking about rapamycin to look at the way people are actually taking it for longevity purposes and to understand the difference between continuous and intermittent use.”
Source: Redirecting...

Also Ted Trent says his testorone levels has not decreased

“I take Rapamycin and my testosterone levels are higher than ever before”
Source: Redirecting...

Here is another N=1 case

“I’ve been taking it for 11 years now and my testosterone levels are quite fine”
Source: Rapamycin | Facebook

Good comment from curtgar on Bikman’s instagram post

“Problem:this study involved transplant patients who dose rapa daily. But the once-every-7-10 days dosing favored by longevity users seems to have very different effects (e.g., it is no longer immunosuppressant.). I’d be cautious about extrapolating from transplant users’ testosterone to that of longevity users.”
Source: Dr. Bikman on Instagram: "If you take #rapamycin in hopes of living longer, you’ll probably need to start taking #testosterone as well. If you inhibit #mtor, you inhibit testosterone. #longevity #lowtestosterone"


In all likelihood rapamycin increases testosterone.


Thanks for the review Krister… better to wait and see if it is a problem before taking any “corrective” action.


This is purely anecdotal and N=1 for what it’s worth. I wanted to test the notion that Rapamycin lowers testosterone. I did a one month washout with no rapamycin. Total testosterone was 892 with 9.3 free.
Three months later, after supplementing 7 mg sirolimus once a week, total T was 826 but free was 10.5. So a 7% decline in total and 11% gain in free. Go figure.
Also looked at Rapa effects on blood chemistry:
After 3 months total chol. was 173, Tri 61, HDL 82, VLDL 12, LDL 79, ApoB 64.


I am a 68 years old male. I tested my testosterone levels recently after 10 months on 4-8mg of Zydus or Bicon weekly / Washout of 6 weeks prior to blood test. I had the blood test done at my July annual physical - so comparison is to the prior year.

Total Testosterone
2022 - 801 // 2023 - 925

Free Testosterone
2022 - 10.6 // 2023 - 13.2

Sex Hormone Bnd Glob
2022 - 71.6 // 2023 - 68.6

Big jump in free testosterone. Well beyond normal range of Free Testosterone (Normal range: 3.3 - 11.6 ng/dL.) Total T also above normal range. Prior to 2022 I was on a compound pharmacy version of 6 mg rapamycin for a year- so probably lower rapamycin blood levels. Actually, 2022 testosterone levels were pretty near the high end too.

Prior to both 2022 and and 2023 annual physicals, I was training for a sprint triathlon. So deep into endurance training - but not super stressful endurance. Say an average of 45 to 90 minutes aerobic training daily. Getting lots of sunshine. Eating from a range of fresh veggies and fruits from a large garden. Eating beef and eggs from the local farmer.

All my other blood measures and blood panel were in a normal range. I am not taking anything like trt or a supplement (that I know of) that would explain the higher testosterone levels. I have no other baseline measures of testosterone to compare than the 2 above.

My physician has ordered another test. I’ll wait till the summer days end and cold creepy dark November arrives. My bet is that my testosterone numbers will have declined.


Big thanks for sharing this! My testosterone went also up a little bit but I have quite high natural testosterone levels.


I have been a bit obsessed wondering if rapamycin can have an effect on training for an endurance event. Some of that obsession is due to your interview with Dr Green and his statement that rapamycin improves heart function in aging. But I am wondering, given my n=1 experience, if in tandem rapamycin also increases testosterone under certain types of stress. Despite a lot more activity with training and lifestyle during the summer (for example - going barefoot) my joints, tendons and ligaments feel at their best - no pain anywhere. My body is building up some sort of resiliency. My conjecture is that in dark cold November my testosterone blood levels will have declined a lot given the co-factor changes of lifestyle.


I think @Joseph_Lavelle can have some experiences to share in this topic.

Here is his podcast

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Thanks @Krister_Kauppi This episode is a blast from the past. John Ooyen is a great guy who opened my eyes to the breadth of factors that go into health and performance. I was hoping to learn about John’s supplement stack but instead learned his athletic performance longevity secret was friendship and camaraderie in sports. Clearly the social cues are important for motivation and morale, but also for stress management. Loneliness is a killer.

But I do think rapamycin helps me. My own experience (4 mos) is I recover better (despite poor sleep; I’m working on it). I attribute this to improvement in my immune system from turning down mTOR periodically. I can workout harder (primarily resistance training), and get better results as a result of less muscle and joint pain. I am not trying for improvement in my cardiovascular fitness (RHR = 40 bpm). Of course I do other things to get better recovery but I am convinced rapamycin is a major driver.


Impact of alcohol on MPS.

I also do not drink alcohol anymore (last 12 mos). Here is a study that says that decision is probably helping my recovery from exercise.


No changes, mine are in the 600s (god damnit). I think I reduced to 400s with spironolactone but quit spiro bc I’m scared of spiro bodies


These people drank a lot of alcohol, like really a lot, like over a bottle of wine (a standard 12.5% bottle if wine contains 94g of ethanol, a 75kg subject would have drank 113g!) . With many things detoxified by the liver it generally only causes a problem when exceeding the capacity of the liver


Yes, certainly more poison is worse than less. I suppose you are saying if the alcohol doesn’t bother you then drink alcohol if you want to? That’s a fine rule. I consume and enjoy around 3 alcoholic drinks per year.


I’m saying that it could be that the effect of less alcohol could be far less (although it could also be the same)

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I just noticed that my T has actually improved slightly. First results in April 2019 at age 45 Pre-Rapamycin.

Versus recently with Rapamycin age 49.

Coincidence? Hmmmm.
Lifestyle-wise very similar. Eat right, exercise, sleep etc.


That could be testing noise.


Agreed, but is a data point regardless and worth sharing. Especially since this thread is asking if Rapa lowers T. Will keep measuring once a year and we will see. Certainly aware of confirmation bias.

One advantage of weekly blood tests is that you can see what level of changes are noise and what are trends. I do use different labs and some times you can see for some biomarkers that different labs seem to get different results. I don’t think that is the case for Testosterone.

These are my recent results for testosterone in nmol/L. (The range quoted for the last lab was 6.68-25.7)

15.6 20.8 17.35 16 19.5 18.3 18.35 17.7 17.6 16.22 15.9

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I had my blood taken for testosterone testing Friday. My 2 prior July tests (see above) had me at or above the high normal range and my doctor was concerned. So we measured again, in a low sunlight dank New England winter.

Results below. I have dipped back into normal range but I am still at the high end of the ranges, particularly given my age (69).

N=1, rapamycin did not decrease testosterone. (I doubt that it increased it but no way to tell). Perhaps it preserves levels by enhancing lean body mass, etc.

Maybe I am an anomaly, but some things I have done and don’t do over the past decade that may help prevent testosterone decline:

  1. 25 mg DHEA daily
  2. 25-50 mg Zinc daily
  3. Exercise - both aerobic (running every other day but only 12-15 miles per week) and strength training twice a week. Generally not a day goes by that I don’t do an activity. But a lot of that is low level stuff like yard work.
  4. Melatonin
  5. 100 mg aspirin
  6. Rapamycin the past 2 years. Currently doing 8mg every 10 days or so.
    *Like most folks on here, I add and drop a range of supplements

Not Take:

  1. Statins (gave me muscle pain)
  2. finasteride (I started a low dose to head off prostrate growth. But quickly dropped it as I thought it might upset my hormonal balance).

Good and bad lifestyle habits

  1. Retired - time to devote to healthy habits
  2. Sleep quality declined some - but not bad
  3. I drink alcohol daily - 2 drinks. Rarely beyond that.
  4. Eat within a 10 hour window. Eat all healthy foods including carbs but make sure I eat plenty of protein. I have a bowl of ice cream an hour before bed most nights.
  5. I am 6’ 188 lbs. That has been my stable weight the past decade. But my belt has gone in a notch since on rapamycin (2 years)
  6. No family history of heart disease or diabetes

My blood tests are within normal ranges generally. But my cholesterol levels would be considered high by most people on this forum.

I measure my aging primarily by how I compare to my younger self. So by that measure I use things like 5k run time (slower but nothing like a nose dive). And I can do more proper pull-ups (15) than I could a decade ago.

By luck or design I expect my youthful activities to continue deep into my next decade. Anyone else having a similar experience? Or is a drop-off more realistic? I am counting on testosterone levels staying at a high level and not dropping off. As well as continuing rapamycin.