Yk11, A Poor Bioavailable 19-nor (hypothesis Not Fact)

[Jamesalan]

First off it's no secret YK11 is not a non steroidal sarm and has never claimed to be. It's not a dht derivative either as claimed by Derek of mpmd.

It hardly survives liver bypass by anecdotal findings not concrete evidence. Which is why many have switched to either injection or sublingual methods for it. I to took it orally and felt jack squat from it. I honestly think people that hyped it got the good ole placebo effect.

Honestly one of the most worthless ones I took orally because I've gone into most not expecting much(if you read my thread I said one time I got more pep in my step and then really had nothing good to say about YK). The ones that really work are the ones that keep working after you get an initial rush.

Norethisterone seems to be a close relative, I've seen it pointed out and dug deeper. Metabolites found after YK11 use were similar to those found in the former.

5β-19-nor-pregnane-3α,17β-diol-20-one
(Progesterone metabolite that converts to DHT it's referred to as a "backdoor androgen", as it does not require testosterone)

5β-pregnane-3α,17α,20α-triol
(Inactive progesterone metabolite and steroid used to test if cortisol levels are low in an individual??)

If the ladder were to be true that would lower myostatin in the body to start with as treatments with cortisol have been shown to raise myostatin levels.

Also if the former is true converting to DHT would give it an anabolic effect as contrary to bro beliefs DHT itself is anabolic and has been argued in literature to be just as if not more anabolic than testosterone.

---ill keep updating this just an intriguing read for whoever cares---


---Stuff stated here could be completely false this is stated from studies and anecdotal findings.---

 

[Richard Dick]

YK11 is a sarm. Technically all steroids synthesised to have different profiles from naturally occurring hormones are sarms, but the term didn't exist when they were marketed. I think what you mean is that it's not a non-steroidal sarm, which is basically what most people mean by sarm.

Anyway, I've never used yk11 but it is interesting if it does inhibit myostatin to a worthwhile degree. I still don't understand what mechanism it uses to do that though. The only thing I've found is that it supposedly increases follistatin but nothing explains how.

 

[Jamesalan]

YK11 is a sarm. Technically all steroids synthesised to have different profiles from naturally occurring hormones are sarms, but the term didn't exist when they were marketed. I think what you mean is that it's not a non-steroidal sarm, which is basically what most people mean by sarm.

Anyway, I've never used yk11 but it is interesting if it does inhibit myostatin to a worthwhile degree. I still don't understand what mechanism it uses to do that though. The only thing I've found is that it supposedly increases follistatin but nothing explains how.

Yes great point, anything more selective tissue wise is a sarm. There are studies that implied tren as a sarm. So yes I'll correct that.

This vector could be explained due to the second metabolite they use now in anti doping testing for YK11 in piss. Apparently that metabolite is found in people with a disease that causes a mutation in cortisol either lowering it or causing a mutation that makes it less effective???

You can see a link in lower cortisol levels and lower myostatin which could increase follistatin?? This is probably incorrect however because then why don't all bodybuilders just take cortisol blockers and then we have a bunch of flex wheelers walking around? Not sure exactly.

I guess the two main points I'm driving home here are that this is a non-oral 19-nor. More plates more dates mistakenly took the fact that it's part of a methyl group to mean it's bioavailable.

And it's definitely steroidal.

 

[Jamesalan]

Here is a graph from a study in 2021 that they were seeing if YK11 would help maintain muscle size vs wasting in sepsis

 

[Jamesalan]

Welp @Richard Dick interesting read I have for you here.

What if I said YK11 was not created by twisting and turning a 19-nor or a dht deriv but a SERM? Lol

1. From Yuichiro Kanno's study in 2008 about SERMs and possible cancer prevention

ERα-selective ligand, (17α, 20E)-3-hydroxy-17,20-[(1-methoxyethylidene)bis(oxy)]-19-norpregna-1,3,5(10),20-tetraene-21-carboxylic acid, methyl ester

Vs

Structure of YK11 discovered by Yuichiro Kanno in 2011

(17α,20E)-17,20--3-oxo-19-norpregna-4,20-diene-21-carboxylic acid methyl ester

So unlike other SARMs like ostarine, rad140, S4, etc etc that were made by basically the same companies with the same goals in mind. This guy works a lot more on gene splicing, mRNA, cancers that type of stuff YK11 is quite literally the only SARM he's discovered and worked on.

Amazing how 2 days of digging in a rabbit hole and I feel like I'm the first to discover this as I've never heard the possibility YK11 was just a twisted and turned SERM but it's right there in the studies.

I could be wrong, but literally there is no history of this dude working with dht derivs, 19-nors, even testosterone. Unless he just started playing with some one day for shits and gigs this is the only thing that makes sense.

Ref: https://www.researchgate.net/profile/Yuichiro-Kanno

 

[Richard Dick]

Yeah, you're right. I don't have access to the 2008 study but there's another one from 2009 where he uses the same notation for yk11 and basically using it as serm in some sort of fish experiment. First mention of the term "yk11" and it being a sarm are in 2011 like you said.

In this paper, we measured VTG1 and VTG2 mRNA induction in male medaka liver, which was treated with ERα-selective ligand, (17α, 20E)-3-hydroxy-17,20-[(1-methoxyethylidene)bis(oxy)]-19-norpregna-1,3,5(10),20-tetraene-21-carboxylic acid, methyl ester

https://www.researchgate.net/public...lective_Ligands_of_Estrogen_Receptor_Subtypes

 

[Jamesalan]

Yeah, you're right. I don't have access to the 2008 study but there's another one from 2009 where he uses the same notation for yk11 and basically using it as serm in some sort of fish experiment. First mention of the term "yk11" and it being a sarm are in 2011 like you said.



https://www.researchgate.net/public...lective_Ligands_of_Estrogen_Receptor_Subtypes

Right it seems he started playing around with the serm, and YK11 was an outcome of it.

I still have yet to find any study he did that stated this poor bioavailability that the forum bros keep going on about.

Makes you start to wonder what possible compounds we are missing out on due to everyone trying to make 1000 variations of SARMs, dht, test, 19-nors etc.

One thing I will give Derek is that estrogen receptors are ignored almost completely as viable muscle building pathways. Which is why turkesterone became a thing, but right now serms are just looked at as "pct bro", drugs.

If you look on the page it says he's now starting to play around with YK11 metabolites. I wonder if he withheld the means of how YK11 was discovered to kinda horde any findings like these for himself. As these sarm companies are just copying what he made, but not knowing the precursor is a big deal.

 

[Richard Dick]

Oh right, I was just assuming it was the same ligand and they switched from studying its effect on the er receptor to the ar receptor. But yeah it is a different notation and I don't know enough about chemistry to know what the changes are really. I'm guessing this department or lab or whatever has a whole bunch of these ligands they're testing, including the cancer/fish liver one (yk08?), and one he's calling yk11. Who knows what they're synthesised from originally.

 

[Jamesalan]

Oh right, I was just assuming it was the same ligand and they switched from studying its effect on the er receptor to the ar receptor. But yeah it is a different notation and I don't know enough about chemistry to know what the changes are really. I'm guessing this department or lab or whatever has a whole bunch of these ligands they're testing, including the cancer/fish liver one (yk08?), and one he's calling yk11. Who knows what they're synthesised from originally.

Right which is why I suspect a SERM as the base not an AAS as he has no history of working with them.

Bro forums and Derek just assumed it was a DHT deriv due to androgenic activity, which the info on one of YK11 metabolites is that it can convert to DHT from a progesterone metabolite. Not through the standard pathway.

 

[Richard Dick]

Serms are nonsteroidal as far as I know, so that's not really possible since yk11 is clearly a steroid. You get steroidal ai's (like aromasin) but they don't function as serms.

 

[Richard Dick]

Well, I don't care enough to pay to see it but basically this is how their ligands came about:

https://www.sciencedirect.com/science/article/abs/pii/S0040402005022143

They used progesterones and estrogens as substrates, like ones you'd find in birth control pills.

Edit - it's explained at the end of this: https://www.researchgate.net/public..._the_Biologically_Active_Diastereomer_of_YK11

A 100 mL two-necked round-bottomed flask, containing a magnetic stirring bar, 1 (1.34 g, 3.9mmol), p-benzoquinone (649 mg, 6.0 mmol) and MeOH/DMSO = 10/1 (45 mL) was fitted with a rubber septum and a three-way stopcock connected to a balloon filled with carbon monoxide. Thea pparatus was purged with carbon monoxide by pumping-filling via the three-way stopcock. A mixture of Pd(tfa)2(66.5mg, 0.20 mmol) and L1 (131 mg, 0.30 mmol) in MeOH/DMSO = 10/1 (10 mL) was added dropwise to the stirred solution via a syringe at −10 °C. After stirring for 48 h at the same temperature, the mixture was diluted with CH2Cl2(150 mL), washed with 5% aq. NaOH (100 mL),and dried over MgSO

It then goes on to say how they seperated this diastereomer they're so interested in from the yk11. Which is interesting in itself since it means the black market might come out with some new super-yk11 now based on this diastereomer.

 

[Jamesalan]

Yeah a doping control study on how to detect YK11 in 2018 had this picture locked behind a paywall but it still pops up on Google images.

So I guess the reddit implying norethisterone was the backbone was possibly correct unless YK11 just gives off similar metabolites to it.

 

[Jamesalan]

I'm all for a super YK11. Let's all get jacked already lmao.

 

[Richard Dick]

My understanding of chemistry is super basic but yeah looking at the diagram for yk11 it looks more similar to norethisterone than dht or anything else. And ethisterine was listed up in that paper I linked earlier about being a precursor so that's your answer I would say.

I wouldn't use it to be honest. If it really was worthwhile people would have cottoned on to it by now, but still no-one really uses it. I'm guessing it probably does work much better as injectable though and the study from two years ago where they're trying to separate the diastereomer that's actually responsible for the effects might come up with something better if the chinese labs start putting it out (maybe they already do?).

 

[Jamesalan]

My understanding of chemistry is super basic but yeah looking at the diagram for yk11 it looks more similar to norethisterone than dht or anything else. And ethisterine was listed up in that paper I linked earlier about being a precursor so that's your answer I would say.

I wouldn't use it to be honest. If it really was worthwhile people would have cottoned on to it by now, but still no-one really uses it. I'm guessing it probably does work much better as injectable though and the study from two years ago where they're trying to separate the diastereomer that's actually responsible for the effects might come up with something better if the chinese labs start putting it out (maybe they already do?).

Yeah which I think it's sht bioavailability is a huge reason it hasn't caught on. Placebo effects arent gonna get you huge. I do hope they keep working on it.

I only really get excited about this one because it really seems like everything else does the same stuff 5000x different ways.

Which I'm finding out lately you can read as much as you want about this crap until you got that syringe in inch into your arm then you start finding out other things you really have no clue about till you start using.

Myostatin inhibition is just an exciting one for me.