383 replies to this topic

[Rocket]

I'm only concerned that GDF11 is going to turn out to be myostatin and have a negative effect on my muscle mass since I am very much into weight lifting and I prefer to see the scale go up every week rather than down.  Even Wagers study showed weight loss in her mice, though she offers no explanation if it was muscle, fat, or...?

 

A reputable lab like Peprotech or Milteny is not going to jeopardize their reputation by sending you myostatin.  But if they accidentally shipped you myostatin, I think you'd know pretty quickly.  For starters, you would never observe the sharp vision/red lights effect that I titrate to.  And GDF11 is anabolic, so if there were no GDF11 in your vial, you'd see no increase in lean body mass.

 

Well, what I meant was that since GDF11 is chemically similar to myostatin, that I am afraid it would behave as myostatin.  Being in the weight lifting crowd, chemicals that are similar to testosterone are called anabolic steroids, with greater or lesser effects as testosterone.  So my concern is that this analogy to Test and AAS would hold true for GDF11 and myostatin.  But, I read the GDF11 knockout mice did not exhibit any greater muscle mass than non-knockout mice.  So it seams GDF11 does not act like myostatin at normal physiological levels.

 

I'm back to square one with locating a supplier.  I have one or two more labs to try and buy from, and if this doesn't work then I am going to resort to trying to locate an intermediate source who could buy it from the labs and resell to myself.  Any suggestions? 

Edited by Rocket, 17 January 2016 - 09:25 PM.

[Nuke]

Hi Steve

 

You mention sharp vision a lot. How is your eye history? Did you ever wear glasses?

 

Reason I ask is, the past 2 years my eyes have definitely been deteriorating. Not to a level where I bother with glasses, but definitely starting to be a PITA. If GDF11 has a chance of slowing this down or turning it around I'm very interested. I have not gone for any tests yet, but I believe its astigmatism.

 

If any other lab rats have experienced anything like this from GDF11, please chip in.

[stevegperry]

You mention sharp vision a lot. How is your eye history? Did you ever wear glasses?

 

Reason I ask is, the past 2 years my eyes have definitely been deteriorating. Not to a level where I bother with glasses, but definitely starting to be a PITA. If GDF11 has a chance of slowing this down or turning it around I'm very interested. I have not gone for any tests yet, but I believe its astigmatism.

 

If any other lab rats have experienced anything like this from GDF11, please chip in.

 

Nuke,

 

I have been nearsighted my whole life and wear contacts, left eye -4.25 diopters and right eye -2.25 diopters.  Before GDF11, my prescriptions for both eyes were .5 diopters higher.  I've also noticed my presbyopia has improved on GDF11 - I can now read the menus in restaurants!  I'm almost 58 and do not need to carry reading glasses.

 

Also, as you may have read above, I titrate my GDF11 dose to a visual effect I call "red lights/sharp vision".  When experience this, I do not take any GDF11.  When "red lights/sharp vision" begins to fade, I top off with a 1 ng of GDF11.  Which at this point is about once/week.

 

Not sure if GDF11 will help with astigmatism or not.  It's certainly worth a try. 

[zorba990]

Since the amount being used is so small, is there any reason that gdf-11 eye drops wouldn't work (like ngf eye drops)?
I have spray bottles for acetyl carnosine water mixture which seems to reduce eyestrain symptoms but doesn't completely rejuvenate the tissues.


http://www.scielosp....ipt=sci_arttext

"A key question raised by this clinical observation and also by studies on animal models [10, 11, 27, 31], is how NGF, a high-molecular-weight protein, is transported from the ocular surface to the posterior segment of the eye when administered topically as eye drops. The evidence currently available points out to two possibile routes: through the cornea, conjunctiva, sclera, choroid, choriocapillaris, and retinal pigment epithelium, or indirectly by traveling through the retrobulbar space to the optic nerve.

Although the clinical observation presented in this report needs to be confirmed on a large scale clinical trial, the good clinical response and the persisting of the improvement during the follow-up stimulate to extend our pilot clinical study. Moreover this study confirms the possibility of using the eye drop NGF for reaching retina, optic nerve and brain in a safe and non-invasive manner, supporting the potential use of topical NGF therapy for ocular and brain degenerative diseases currently considered untreatable."

[stevegperry]

Since the amount being used is so small, is there any reason that gdf-11 eye drops wouldn't work (like ngf eye drops)?
I have spray bottles for acetyl carnosine water mixture which seems to reduce eyestrain symptoms but doesn't completely rejuvenate the tissues.

 

GDF11 has a molecular weight of 45,091 Daltons: http://www.phosphosi...owAllSites=true

 

NGF has a molecular weight of 26,959 Daltons: http://www.phosphosi...owAllSites=true

 

GDF11 is definitely a bigger molecule, but not a magnitude bigger, so if NGF works, GDF11 eye drops might work also.  I have no idea what concentration you should use though.  Start low - maybe 5 ng - and work your dose up/down based on efficacy. 

[pone11]

This is a fantastic contribution to Longecity.   Do you have any data on the measured endogenous levels of GDF11 in humans for young people versus old?   Charting the min, max, and median values at at different ages from birth would give us additional hints on appropriate human dosing?

 

I would agree with the comment that you might want to do a full body scan, or if you can afford it a PET scan, looking for any tumors you might have started inadvertently.

 

The results that most impress me are those concerning sight, smell, and hearing.   I think improvement in those things over the age of 50 would be difficult and all of those things can be objectively measured.

Edited by pone11, 27 February 2016 - 11:02 PM.

[pone11]

Steve,

 

Thank you very much for this discussion and the excellent experiment. A few questions:

Can you elaborate a bit about the pharmaco-dynamics of exogenous GDF11? What is the half life; are the metabolites also active; and very importantly, is there a negative feedback loop that may result in down-regulation of endogenous production when you inject the substance?

 

Is frequent blood donation something worth considering for those who cannot utilize exogenous GDF11? The idea was that when new blood is produced after donating blood, the new one has a richer mixture of substances promoting tissue regeneration. I don't know if anyone specifically tried to see if serum concentrations of GDF11 goes up after donating blood though.

 

Finally, I guess you think that the overall risk is fairly low, which is at least what I gather from reading the attached word document. Can you elaborate a bit on this please if you don't mind? Is GDF11 something that can promote the growth of cancerous tissue? Is it something that we see in higher concentrations in cancerous tissues? If not cancer, what other potential problems come to mind, and please share of there are any precautions that can be taken to prevent them.

 

Finally, you have mentioned in the word document that GDF11 may not be enough to fully halt the aging process and that other hormones such as GH, Thyroid and LH/FSH may be needed to be replaced/restored to youthful levels. Luckily all of those hormones or their mimetics are available as endogenous substances. (in the case of LH, at least one can inject testosterone or use HCG as a LH mimetic). Will you be adding these to your regimen?

 

That's a great question regarding endogenous production of GDF11 downregulating.   I guess you could measure the endogenous levels before injections begin, then well into the protocol, then measure every day after you stop until you hit a minimum measured value that heads back up endogenously.    The difference between the peak measurement before you stop, and the lowest endogenous level after you stop, might suggest an approximation to how much of your endogenous production you downregulated by the injections.

 

All of this leads to the obvious question:  is there any commercial lab that can cost effectively measure GDF-11 levels, and is there any special preparation required for the blood before you send to them?   What is the cost of the test?

[pone11]

Steve,

 

Thank you very much for this discussion and the excellent experiment. A few questions:

Can you elaborate a bit about the pharmaco-dynamics of exogenous GDF11? What is the half life; are the metabolites also active; and very importantly, is there a negative feedback loop that may result in down-regulation of endogenous production when you inject the substance?

 

Is frequent blood donation something worth considering for those who cannot utilize exogenous GDF11? The idea was that when new blood is produced after donating blood, the new one has a richer mixture of substances promoting tissue regeneration. I don't know if anyone specifically tried to see if serum concentrations of GDF11 goes up after donating blood though.

 

Finally, I guess you think that the overall risk is fairly low, which is at least what I gather from reading the attached word document. Can you elaborate a bit on this please if you don't mind? Is GDF11 something that can promote the growth of cancerous tissue? Is it something that we see in higher concentrations in cancerous tissues? If not cancer, what other potential problems come to mind, and please share of there are any precautions that can be taken to prevent them.

 

Finally, you have mentioned in the word document that GDF11 may not be enough to fully halt the aging process and that other hormones such as GH, Thyroid and LH/FSH may be needed to be replaced/restored to youthful levels. Luckily all of those hormones or their mimetics are available as endogenous substances. (in the case of LH, at least one can inject testosterone or use HCG as a LH mimetic). Will you be adding these to your regimen?

 

What I would badly like to see is a full panel of his adrenal and pituitary hormones before he started GDF11, and at intervals after he started.   My guess is that they all went up a bit in response to the therapy.   For transitory chemicals like adrenalin, the collection would need to be 24 hour urine not serum levels.

 

Taking those hormones without monitoring the others is dangerous.   I used to take a handful of supplements every day, and what these managed to do was upregulate my metabolism and send all of my adrenal and pituitary hormones skyrocketing.   About 80% of my hormones were above the red line or right at the highest end of normal.  Things got so bad they started checking me for pituitary and adrenal tumors.   One of my allopathic physicians saw all the supplements I was taking, then ordered me off all of them cold turkey, and my hormones fell back to normal ranges over a six month period.

 

When tinkering with hormones, never assume you are affecting just one.  These things have complex pathways and there is a lot of endogenous regulation going on that may affect levels of other hormones and peptides.

Edited by pone11, 28 February 2016 - 12:20 AM.

[pone11]

 

Regarding that study said GDF11 increase rather than decline with age, that was recently refuted by Amy Wagers in the Science Magazine article:

 

http://news.sciencem...ard-team-claims

 

As I have mentioned before, the assays for GDF11 are not refined at this point and often measure both myostatin and immunoglobin as well.

 

 

What is scary in the above quote is the section that paraphrases Wagers as saying that "...commercially purchased GDF11 can vary in the actual level and activity of protein."

 

That makes it even harder to compare your dosing against any measurement of endogenous levels of GDF11 (and those measurements are also very controversial and potentially not measuring the actual GDF11 levels in isolation).

 

It's probably important for purposes of duplicating your results that people use the identical product you have used, to avoid one side of this problem.

[pone11]

 

I have been on GH for at least 20 years and on injectable testosterone for 10 years. When I started taking GDF11, I went off of everything since I didn't want any other hormone clouding the results.  Unfortunately, my IGF-1 and free testosterone levels fell to that of a normal 57 year old. And my body fat started to go up a bit. So I resumed my GH/testosterone regimen alongside my GDF11 supplementation, and now I'm in decent shape...

 

 

Can you publish any data showing your GH and testosterone levels before and during the experiment?

 

What metabolite were you measuring as the proxy for testosterone?   You measured both serum and free testosterone?

[pone11]

The assays to measure GDF11 are not ready for prime time yet since they also measure GDF8 and immunoglobin.  Hopefully this will change soon.  I actually titrate my dose to having the very sharp vision/red lights in the afternoon.  And no side effects, of course.

 

 

Can you talk about this titration in more detail?   When you overdose, does the sharp vision diminish?   Or is the titration only to establish a minimum effective dose?

[pone11]

Here's a piece that doesn't hang together for me:

 

Perry describes a dosage of .05 ug, compared to a whole-body inventory of 80 ug,   This implies that the exogenous GDF11 builds up in the body over at least a week before it makes a substantial change.  And yet he describes benefits (and side-effects) that he can feel from the first dose.  The low dosage also doesn't seem to jibe with the claims about the short half-life of GDF11. http://www.nature.co...x.2013.567.html

 

Testing the effects of long-term GDF11 treatment may be difficult because the protein has poor solubility and stability.

“These proteins are notoriously hydrophobic and very hard to work with,” said Kumar. “They are very short proteins and have a very short half-life.”

“The problem with administering GDF11 is that it's probably unstable or not long-lasting,” added Sadoshima. “It would be very difficult to keep it at high levels of circulation.”

“You might need to administer this chronically,” said Hill. “The ideal thing would be a small molecule agonist of cardiac-specific receptors” that mimics the effect of GDF11 but has better pharmacodynamics.

→ source (external link)

 

It would be 0.80 ug, but I had the same thought, even after making that correction.  His current doses are so low that if GDF-11 is short-lived he could not be altering his whole-body inventory.   That in turn suggests the opposite hypothesis, that maybe GDF-11 bioaccumulates and reaches steady state over long periods of time.   This however contradicts the experiments that seem to require daily injections.

 

Perhaps GDF-11 is actually acting as a signal to something else.   Maybe there is another peptide that rides along with GDF-11 that acting as the signal.

 

I am NOT trying to advance any specific hypothesis.  I am observing - like you - that there is something unusual about his dosing, and it is hard to explain his positive result in light of other studies on animals.   It suggest there is science we don't understand here yet.

Edited by pone11, 28 February 2016 - 01:25 AM.

[stevegperry]

Sorry to take so long to reply.  Just got back from skiing Whistler for a week.  Which is itself a good testimonial for GDF11 - skied hard, rarely got winded, and had no joint or knee issues which often comes with a long ski trip.  

 

Now let's answer some questions:

 

Can you talk about this titration in more detail?   When you overdose, does the sharp vision diminish?   Or is the titration only to establish a minimum effective dose?

 

When you are in an overdose state, you still get the sharp vision.  Though if you have a bad case of GERD, you are hardly applauding your sharp vision.  I have not taken GDF11 for over 3 weeks and am still experiencing the sharp vision/red lights every day.  And feeling great, energized with plenty of stamina.

 

I will not take any more GDF11 until the sharp vision disappears, which may be months from now.  Amy Wagers did say that she thought GDF11 was a "reset" thing and at this point I agree with her.  I think that once you "fill the tank", down regulate, reset - whatever you want to call it - you need very little GDF11 to maintain things.

 

I think what may have happened is that I started with a fairly decent deficit of GD11, which is why I was able to tolerate high doses.  But over time, stem cell DNA was repaired/stem cell progenitors were moved into an active state, and then you need very little to maintain it.  And if you push the envelope and take too much GDF11, you move too many progenitor cells into an active state and you get inflammation.  Which in me manifests itself as GERD and esophageal pain.  And if you really take too much GDF11, it starts to cross bind with the activin type 2 (myostatin) receptors which wreaks even more havoc.  This is why I think some of the mouse studies, most of which grossly overdose the mice, the mice end up with muscular atrophy.

 

BTW, I took another set of biomarkers in late January, which I will be publishing soon.  A few are already up on gdf11rejuvenation,com.  Note my cognitives, which are the best I have ever done.  My visual memory never got above 50th percentile, and now I am at 98th percentile.  For once, that annoying test of indistinguishable squiggles, elevator buttons, etc. actually made sense.  Also, on my UCLA immune, note an increase in naive suppressor T cells, which are the best measure of immune age.  On the negative side, there was an increase in senescent T cells, which is not good.  Based on this, I am pretty sure GDF11 does NOT clear senescent cells.  Though I hear that some of you are working on that!

 

Stay tuned.

 

Steve

 

 

 

 

 

[bulky]

Abnova sells gdf11 and they claim 98% purity

 

Does anyone have any experience with this company?

 

http://www.abnova.co...atalog_id=P4096

 

Thanks

[Daniel Cooper]

Very interesting thread.  I look forward to further updates.

 

 

[tunt01]

Very interesting thread.  I look forward to further updates.

 

I don't mean to sound grim, but isn't there a pretty unknown cancer risk here?

Edited by prophets, 04 June 2016 - 10:41 AM.

[stevegperry]

Hello Longecity,

 

Check out my download site, GDF11Rejuvenation.com, and look at the paper in the "Published Papers" folder called "Cardiovascular Effects of GDF11".  Great paper - mostly good news on GDF11 including the fact that centenarians have a mutation to K153R42 dramatically improves furin processing which results in more bioavailable GDF11.  Note also that heterochronic parabiosis works better than GDF11 leading the author to postulate that IGF-1 is needed in the mix.  Yes!!  I think I am doing a bit better than most of my cohort, especially in the vision area, because I take GH.  Please read the paper and LMK your thoughts.

 

Also, please go to www.raadfest.com and look at the presenters.  Like what I wrote?  It will certainly spark some debate from other anti-aging camps such as telomeres and mitochondria!

This is a TED style talk and I’ll have only 15 minutes to present my GDF11 study on aging biomarkers of 20 volunteers, which strongly suggest that GDF11 initiates major cardiac, skin, muscle and cognitive repair.

 

Hope you can make it – make sure you put the discount code “PERRY” in the cart for $80 off.  See you on August 5^th at RAADFest!

 

Steve

[thedevinroy]

Been scrolling through the threads and haven't noticed anyone mention transdermal administration. Would that still work? I did read it wasn't a large protein and was rather stable at room temperature. I know it's expensive but... I'm not really feeling the whole needles thing. I'd pay to remove that experience.

By the way Steve, good luck! That's awesome, and it's great to hear a sorry like yours with so much promise. I love the research you've compiled in your report.

Edited by devinthayer, 21 May 2016 - 05:14 AM.

[stevegperry]

Thanks Devin!  2nd round of biomarkers coming up for my cohort in June and July.  If they correlate to mine, it'll be huge.

 

As for transdermal administration, don't hold your breath.   GDF11 is a big molecule, 45,091 Daltons, so it has to be injected at this point.  If you use insulin needles, it's no big deal.  And I only inject it once/week at this point.

[tunt01]

Pretty good synposis of the conflicting data and concerns over the original Loffredo/Wagers work.  Anyone looking at GDF-11 should read it.

[thedevinroy]

Does not pass the 500 Dalton rule... Huh. Any way to upregulate production of it in a benign or healthy way to achieve the same effects?


Sent from my iPhone using Tapatalk

[stevegperry]

Not that I know of.  Maybe someday we will have a GDF11 secretagogue, but right now, you have to inject it.

[pone11]

Steve, just curious why are you still taking GDF11 in light of all of the newer research on it?  Aside from the confusion over whether they are measuring GDF8 / GDF11 or immunoglobulin, even the latest Wagers research shows the rodents lose weight, suggesting the strong possibility of muscle loss.  Other groups have been much less ambiguous and are making pointed claims that GDF11 either does nothing or reduces muscle growth.

[thedevinroy]

Steve, just curious why are you still taking GDF11 in light of all of the newer research on it? Aside from the confusion over whether they are measuring GDF8 / GDF11 or immunoglobulin, even the latest Wagers research shows the rodents lose weight, suggesting the strong possibility of muscle loss. Other groups have been much less ambiguous and are making pointed claims that GDF11 either does nothing or reduces muscle growth.

He kind of goes over that. Because it was so hazy, he had to take a chance. When he did, he noticed age reversal effects with heartburn as the only side effect. I mean how do you still have doubts at that point?

[stevegperry]

Pone,

 

The controversy about GDF11 levels rising vs. falling with age has been addressed many times in this thread.  GDF11 and GDF8 are 90% homologous and there is no accurate GDF11 ELISA test.  Work is being done using https://en.wikipedia...ss_spectrometry for a more accurate GDF11 test.

 

Also, look at my biomarkers on GDF11Rejuvenation.com.  Note that losing muscle mass has not been an issue for me.  Also, the published papers section of my site, there is a new paper called "Cardiovascular Effects of GDF11" which is very pro GDF11.

[pone11]

Pone,

 

The controversy about GDF11 levels rising vs. falling with age has been addressed many times in this thread.  GDF11 and GDF8 are 90% homologous and there is no accurate GDF11 ELISA test.  Work is being done using https://en.wikipedia...ss_spectrometry for a more accurate GDF11 test.

 

Also, look at my biomarkers on GDF11Rejuvenation.com.  Note that losing muscle mass has not been an issue for me.  Also, the published papers section of my site, there is a new paper called "Cardiovascular Effects of GDF11" which is very pro GDF11.

 

If you read the two main papers - that followed the original Harvard paper - on GDF11 levels, and the Harvard team response to that, it is very clear that the Harvard team is backing away from its original claims.  One of the two teams showed that GDF8 outnumbers GDF11 by a factor of 500, and in their response paper the Harvard team now refers to a combined GDF11/GDF8 measurement, apparently distancing themselves from the original GDF11 claim.  There was the Harvard response about immunoglobulin in one of the two follow-up studies, but those authors pointed out that they had two different ways of making their measurements and Harvard had only responded to one of those.  In the follow-up Harvard paper, they report the mice lost weight.  That alone is a huge step back on the original claim as well.

 

What I am wondering is could most of your positive result be attributed to a much higher aerobic fitness level?  The single most obvious benefit you got was a sense of energy that allowed you to do very difficult backpacking trips and other forms of exercise, more strenuously and for longer periods than before.   That still begs the question did GDF11 do something to your blood chemistry that gave you this enhanced sense of energy.

 

One of the two rebuttal papers to Harvard actually spends a lot of time talking about the physiological effects noted in prior studies for GDF8 and GDF11.  Ignoring whether each of these is an agonist or antagonist to the growth process, that paper indicates that GDF11 normally accounts for skeletal framing during early development, whereas it is GDF8 that appears to be related to muscle growth.  Based on the revised Harvard claims, it would be difficult to see how we could believe GDF11 by itself rejuvenates tissues.  

 

It's tempting to jump on this, but I am starting to feel it is a few years too early still.  There are some important details they are still figuring out and it's not clear that GDF11 only does good things in these studies.  I feel like I would be hoping for a sudden improvement in energy levels and ability to train aerobically, but I might be potentially compromising my muscle tissue.   I really wish Harvard had done a test on longevity and measured body fat and lean tissue changes for test and control groups over their lifetimes.   That would have gone very far towards evaluating whether the changes GDF11 makes to lean tissue is benign. 

Edited by pone11, 16 June 2016 - 06:23 AM.

[Hebbeh]

http://www.longecity...se/#entry778816

http://www.longecity...ge/#entry778906

[stevegperry]

Pone,

 

I would say that the Walker/Wagers/Lee paper entitled "Cardiovascular Effects of GDF11" is very pro GDF11.  Note that at the top of page 1131 they still maintain that GDF11 can reverse cardiac hypertrophy which correlates with my impressive cardiac biomarker improvement.

 

And they also acknowledge something I have known all along - the proper dosing window for GDF11 is very, very tight:

 

"Thus, GDF11 can initiate a negative feedback loop that may antagonize its own activity, as well as that of other activin/myostatin ligands. The existence of such a feedback mechanism suggests the likely importance of maintaining signaling by these ligands within a tight physiological range."

 

Getting the right dose of GDF11 in humans is not easy, but it's got to be a hell of a lot easier than mice who can't give much feedback. At least we humans are smart enough to reduce the GDF11 dose when side effects like GERD and other types of inflammation occur.  When mice lose weight on GDF11, their dose is surely too high which causes GDF11/myostatin cross binding, as well as the expression of follistatin.  Note that I have my GDF11 fairly well tuned at this point and have seen quite a bit of muscle mass gain.

 

And now for my favorite part of this paper:

 

"Systemic injection of rGDF11 recapitulated several beneficial effects of heterochronic parabiosis, including vascular remodeling of the aged blood vessels in the subventricular zone and increased numbers of neural stem cells in this area. rGDF11 also induced the proliferation of brain capillary endothelial cells and activated the SMAD2/3 pathway in vitro.

 

The in vivo effects of rGDF11 were not as prominent as those seen with heterochronic parabiosis, suggesting that additional

 

factors may be present in the young circulation that exerts these central nervous system effects.144 Future studies testing different concentrations of rGDF11,111 different treatment

 

lengths, and coinjection of factors such as insulin-like growth factor 1 or epidermal growth factor that affect neural stem cell proliferation and/or vascular behavior may clarify this issue.

 

Almost all of my cohort has reported considerably improved mental clarity including many who report vivid dreams which is probably associated with increased numbers of neural stem cells and vascularization  Also, note they suggest other blood borne peptides, like IGF-1, are probably necessary to completely mimic the effects of parabiosis.  I agree with this - I feel I have had better results than anyone with GDF11 because I have been taking GH for 25 years and continue to take a unit/day.

 

As for the recent paper from the Mayo Clinic stating that GDF11 levels go UP with age - if anyone has the full version of this paper, please send it to me.  This study is more compelling, since they used LC/MS to measure GDF11 levels, which is far more accurate than ELISA. Still, antibodies are used and cross binding can occur.  Also, another reason I want to read the paper is to see how large a group they are looking at.  I've seen GDF11 levels all over the place for people of the same age.  What would really be a compelling study is to take a group of say 20 people, that have serum frozen from 10 years ago and compare their present day GDF11 levels with GDF11 from their 10 year old serum.  That would be eliminate the noise of GDF11 levels being quite variant and strongly suggest age related decline of GDF11.

 

At the end of the day, biomarkers are going to tell us the most about GDF11 efficacy.  I do have at least four people in my cohort who took baseline biomarkers and will hopefully do round 2, post GDF11, soon.  If their results, especially in the cardiac area, correlate to mine, then that's huge.  If not, well then we may need to introduce GH into the mix.  When more biomarkers come in, I will post them on gdf11rejuvenation.com and let everyone know they are there.

 

 

 

[Hebbeh]

 Using this platform, researchers compared age-associated changes in GDF11 and myostatin in healthy men and women between 20 and 94 years old. They discovered that although myostatin is higher in younger men than younger women and declines in healthy men throughout aging, GDF11 levels do not differ between sexes nor decline throughout aging. In an independent cohort of older individuals with severe aortic stenosis, researchers found that those with higher GDF11 levels were more likely to be frail and have diabetes or prior cardiac conditions. Following valve replacement surgery, increased GDF11 was associated with a higher prevalence of re-hospitalization and multiple adverse events.

 

“As a methodological advancement, our assay will be useful for better understanding the basic biology of GDF11 and myostatin, and through its use, we’ve discovered that GDF11 may be an important biomarker of frailty and comorbidity. It’s a great example of bench-to-bedside research with direct relevance to medical management decisions,” says Marissa Schafer, Ph.D., a postdoctoral fellow in Dr. LeBrasseur’s laboratory and lead author of the study.

 

 

http://newsnetwork.m...inked-to-aging/

 

10.1016/j.cmet.2016.05.023

 

[stevegperry]

As I said in my last post, let's see the full paper here and take a look at the raw data.  Though LC/MS is a more accurate method, antibody purity is still an issue when you have GDF11 and myostatin 90% homologous.  

 

BTW, my empirical data with my cohort shows that young people are very sensitive to GDF11 - a dose of only 4 ng can cause GERD and other inflammation issues.  Older people can tolerate much higher doses.  What does this suggest to you?