L-Carnitine Reduced Efficacy of T3

[danieltx]

I don't use l-carnitine but I know it's popular here. Dr. Scott Stevenson discussed this today on his weekly Think Big Bodybuilding show. In summary l-carnitine prevents T3 from getting into the cell nucleus.

 

[btails]

I can't remember exactly where but Dr. Scott has discussed this before. Perhaps on the l carnitine thread here or on another video.

Just an FYI incase any reader is looking for more info

https://www.professionalmuscle.com/forums/index.php?threads/l-carnitine-effect-on-thyroid.131489/#post-2301428

 

[Stewie]

Scott and I discussed this pretty thoroughly in the past.

https://www.professionalmuscle.com/forums/index.php?threads/my-fascination-with-inj-l-carnitine.166391/page-21#post-2916644

And around 2014.

https://www.professionalmuscle.com/forums/index.php?threads/t3-usage.115384/page-2#post-1880009

 

[CorgisOnTren]

Watched the episode, it was solid.

Seems like the only use case really for bodybuilding would be using it to shift to burning fat for energy, but we have plenty of other tools to do that with.

As far as I’m aware too, there’s never actually been any true evidence to prove the theory that it increases androgen receptor density.

 

[specter]

Watched the episode, it was solid.

Seems like the only use case really for bodybuilding would be using it to shift to burning fat for energy, but we have plenty of other tools to do that with.

As far as I’m aware too, there’s never actually been any true evidence to prove the theory that it increases androgen receptor density.

He has posted studies on this several times, ill see of o can get him to come here and answer.

 

[homonunculus]

Hey Fellas,

We just happened to talk about this a bit on yesterday's podcast, but there's another one (I'd have to search, but it's a Muscle Minds podcast and L-Carnitine should be in the title) where I delve into a it a bit more.
I dig much more extensively into the topic in a 2 part article on John Meadows' site I did about a year or so ago now. SUPER fascinating topic, IMO.

-S

 

[homonunculus]

As far as references, I can post the bibliographies for the two part article on John's site if interested. (Will have to break it up into a few parts... LOL)

-S

 

[cesarpaiva]

Alex Kikel mentioned on his prep forum coach that the T3 / T4 reduction is only when talking about the oral form, not the injectable... what are your guys thoughts?

 

[CorgisOnTren]

He has posted studies on this several times, ill see of o can get him to come here and answer.

Interesting, I’d definitely like to see. They discussed this topic on one of the recent AB lives and couldn’t find anything except a study, but in both groups they resistance changes and the difference in androgen receptor density increase in just adding resistance training vs resistance training + l carn (2g oral) was minimal to say the least (small enough it could just be chalked up to individual variance).

Alex Kikel mentioned on his prep forum coach that the T3 / T4 reduction is only when talking about the oral form, not the injectable... what are your guys thoughts?

Perhaps he said this because the only studies done on l carn are pretty much all using oral administration? I don’t see why it’s effects on thyroid would change due to the route but who knows.

 

[specter]

Interesting, I’d definitely like to see. They discussed this topic on one of the recent AB lives and couldn’t find anything except a study, but in both groups they resistance changes and the difference in androgen receptor density increase in just adding resistance training vs resistance training + l carn (2g oral) was minimal to say the least (small enough it could just be chalked up to individual variance).


Perhaps he said this because the only studies done on l carn are pretty much all using oral administration? I don’t see why it’s effects on thyroid would change due to the route but who knows.

Well he just posted above so ? Maybe try and talk to him

 

[Cerberus777]

The big question is does it reduce t3 efficiency more than it assists fat burning by moving fat into the mitochondria? If you need to just take 25mcg of t3 to return to baseline and the L-CARITINE is assisting in fat loose through a way that doesn't increase blood pressure or heart rate...it's worth it IMHO

 

[CorgisOnTren]

Well he just posted above so ? Maybe try and talk to him

Wow reading back my own comment that shits barely legible lol. That’s what I get for multitasking talking on the phone with my girl while trying to explain a study hopefully it made sense. Essentially two groups with one taking 2g oral l carn, both resistance trained and saw increased AR density, with the l carn group increasing a very small % more (like 1 or something insanely small), which you could chalk up to genetic difference or just a fluke.

@homonunculus you ever seen anything convincing on the topic of l carn and AR density/sensitivity?

If you need to just take 25mcg of t3 to return to baseline and the L-CARITINE is assisting in fat loose through a way that doesn't increase blood pressure or heart rate...it's worth it IMHO

Well if the issue that Scott stated is that it doesn’t allow t3 to enter the cell properly, I would assume that could possibly still translate to exogenous t3 no?

Additionally, as far as the fat burning effects I recall Kurt Havens explaining that L Carnitine isn’t even the limiting factor in that process of transporting the fat but actually Aceytl CoA, but this can’t be supped with unfortunately.

 

[homonunculus]

Wow reading back my own comment that shits barely legible lol. That’s what I get for multitasking talking on the phone with my girl while trying to explain a study hopefully it made sense. Essentially two groups with one taking 2g oral l carn, both resistance trained and saw increased AR density, with the l carn group increasing a very small % more (like 1 or something insanely small), which you could chalk up to genetic difference or just a fluke.

@homonunculus you ever seen anything convincing on the topic of l carn and AR density/sensitivity?

In the article on John's site, I do a mini-dive into the (only) study (from Bill Kraemer's lab) as far as I know that's used to support the idea that L-Carn up regulates the AR. The study was so fraught with issues, but it wasn't convincing IMO. I just looked back at the article I wrote and for instance, in that study(Kraemer et al., 2006) , they had an exercise order issue (it wasn't randomized, no true pre-exercise measurement relative to the second of two successive bouts), a loading time issue (too short), and a washout time issue (again too short). (For many reasons other than this as well, I wish John were still around so I could ask if I could post some excerpts of that article...)

Kraemer WJ, Spiering BA, Volek JS, Ratamess NA, Sharman MJ, Rubin MR, French DN, Silvestre R, Hatfield DL, Van Heest JL, Vingren JL, Judelson DA, Deschenes MR, and Maresh CM. Androgenic responses to resistance exercise: effects of feeding and L-carnitine. Med Sci Sports Exerc 38: 1288-1296, 2006.

-S

 

[EnhancedFatGrappler]

Dr. Scott and Mr. Scott talked about it more in depth in a previous podcast episode, that one really sold me on not using a high amount of L-Carnitine, be it orally or injectable.

My take away was basically if you feel you have low thyroid symptoms, using ~200 mg for a bit, and days off in between, can help if you have low carnitine stores in the muscle, which would be possible during a long diet. Taking a bit of T3 with it won't hurt either, but going way over 25 mcg will just burn away muscle.

 

[Elvia1023]

Everytime I add carnitine in I improve. It compliments things very well and it's one of my fav supplements to take. I have never had any issues with fat burning. I know it's been stated it's not thyroid blood markers but after years of on/off usage I have never had any issues in that regard. I don't use t3/t4 so it's a non issue for me. Like with anything common sense needs to be used and whilst a high dose can be effective I recommend cycling carnitine on/off through the year.

 

[CorgisOnTren]

I don't use t3/t4 so it's a non issue for me.

From what I could tell it effects the t3 entering the cell whether endogenous or exogenous I believe, @homonunculus please correct me if wrong.

Agreed it definitely seems like a dose/duration dependent thing.

 

[Elvia1023]

From what I could tell it effects the t3 entering the cell whether endogenous or exogenous I believe, @homonunculus please correct me if wrong.

Agreed it definitely seems like a dose/duration dependent thing.

I read that but again it's never been an issue for me. In simple terms I use it and it helps me and when I diet with it I get leaner. It's not like it's fucking up my thyroid production/utilization that it's preventing me from reaching my goals. Some of my experiments have never been scientific but I learnt a lot. Even when I tried a very high dose whilst it worked it was totally unneeded imo. Just the same as when I have tried 500mg test and 1500mg test and we learn what works for us through trial and error. Nevertheless, I have always got great results using between 400-1000mg inj carnitine and felt/looked better in the higher doses of that range (600-1000mg).

It's never worsened my results when I went above 400mg and I experienced the opposite but reading through the literature it could be a potential issue for some especially if they are high dosing over long periods of time. Well even lower dosing over long periods but I have known quite a few guys to take small amounts (200-400mg) for long periods and again they have never had any issues getting in great shape. It's definitely something to be aware of and to see how you respond just the same as with most supplements/drugs.

 

[specter]

I read that but again it's never been an issue for me. In simple terms I use it and it helps me and when I diet with it I get leaner. It's not like it's fucking up my thyroid production/utilization that it's preventing me from reaching my goals. Some of my experiments have never been scientific but I learnt a lot. Even when I tried a very high dose whilst it worked it was totally unneeded imo. Just the same as when I have tried 500mg test and 1500mg test and we learn what works for us through trial and error. Nevertheless, I have always got great results using between 400-1000mg inj carnitine and felt/looked better in the higher doses of that range (600-1000mg).

It's never worsened my results when I went above 400mg and I experienced the opposite but reading through the literature it could be a potential issue for some especially if they are high dosing over long periods of time. Well even lower dosing over long periods but I have known quite a few guys to take small amounts (200-400mg) for long periods and again they have never had any issues getting in great shape. It's definitely something to be aware of and to see how you respond just the same as with most supplements/drugs.

One think i think ppl fail to realise is, it may have that effect on T3 but thats not to say you wont be burning fat, same thing some years ago there was a paper on vit c lowering the effect of training but that doesnt mean you will have 0 effect from the training. In my oppinion this is over analyzing things.

 

[aHarness]

One think i think ppl fail to realise is, it may have that effect on T3 but thats not to say you wont be burning fat, same thing some years ago there was a paper on vit c lowering the effect of training but that doesnt mean you will have 0 effect from the training. In my oppinion this is over analyzing things.

I would say discussing inhibiting the functions of t3 in the body with a compound often used in a dieting setting not over analyzing…

 

[specter]

I would say discussing inhibiting the functions of t3 in the body with a compound often used in a dieting setting not over analyzing…

Well lets look at it from a "bro science" point, so far we have alot of diff well nown BBérs using it and no one sofar have had any issues loosing fat or getting in shape, so im kinda wondering what exactly you are lookin for here ? and btw before ppl jump down my throat im all for discussing stuff i love the science, im just having issues here finding out what the problem is we are lookin for ?