L Carnitine and Thyroid

[KingOfSushi]

I’ve seen lots of potential indications that L Carnitine has effects on thyroid hormone, has anyone seen this?

Wanting to use it myself to maximize insulin sensitivity, but this is the one thing holding me back. I do take exogenous thyroid to replace my own, so unsure if it would interact with that.

Interested in hearing anecdotes.

 

[Love_to_Bodybuild]

I’ve seen lots of potential indications that L Carnitine has effects on thyroid hormone, has anyone seen this?

Where have you seen potential indications l carnitine effects thyroid hormone ?

 

[BigZeus]

I believe L Carnitine doesn't affect Thyroid hormone.

 

[KingOfSushi]

Where have you seen potential indications l carnitine effects thyroid hormone ?

Effects of carnitine on thyroid hormone action - PubMed

By experiments on cells (neurons, hepatocytes, and fibroblasts) that are targets for thyroid hormones and a randomized clinical trial on iatrogenic hyperthyroidism, we validated the concept that L-carnitine is a peripheral antagonist of thyroid hormone action. In particular, L-carnitine inhibits...

pubmed.ncbi.nlm.nih.gov

Carnitine is a naturally occurring inhibitor of thyroid hormone nuclear uptake - PubMed

Carnitine (3-hydroxy-4N-trimethylammoniumbutanoate) is a naturally occurring quaternary amine that is ubiquitous in mammalian tissues (concentrations in the order of mM). Based on limited studies of approximately 40 years ago, carnitine was considered to be a peripheral antagonist of thyroid...

pubmed.ncbi.nlm.nih.gov

Scott Stevenson addresses it well here too:

(there should be time stamps)

Perhaps @b-boy may have some insight? I know he’s used it for a long time, as well as our friend @ChaseIrons who joined us recently.

 

[ChaseIrons]

Effects of carnitine on thyroid hormone action - PubMed

By experiments on cells (neurons, hepatocytes, and fibroblasts) that are targets for thyroid hormones and a randomized clinical trial on iatrogenic hyperthyroidism, we validated the concept that L-carnitine is a peripheral antagonist of thyroid hormone action. In particular, L-carnitine inhibits...

pubmed.ncbi.nlm.nih.gov

Carnitine is a naturally occurring inhibitor of thyroid hormone nuclear uptake - PubMed

Carnitine (3-hydroxy-4N-trimethylammoniumbutanoate) is a naturally occurring quaternary amine that is ubiquitous in mammalian tissues (concentrations in the order of mM). Based on limited studies of approximately 40 years ago, carnitine was considered to be a peripheral antagonist of thyroid...

pubmed.ncbi.nlm.nih.gov

Scott Stevenson addresses it well here too:

(there should be time stamps)

Perhaps @b-boy may have some insight? I know he’s used it for a long time, as well as our friend @ChaseIrons who joined us recently.

I have not seen an issue with my thyroid numbers… but i am also on 18iu hgh a day and 100 t4 and 25 t3 so I don’t count that being said I’ve seen tons of customers bloodwork while on carnitine and haven’t seen any thyroid numbers skewed

 

[D-NUTZ]

I wonder if it has more to do with how Carnitine is used to control a thyroid storm. Maybe it’s effects only happen in that scenario?

I’m unsure and just spit balling

 

[KingOfSushi]

@D-NUTZ @ChaseIrons in the video discussion I linked I think they actually said it won’t even fully reflect on bloodwork if it IS effecting thyroid, because it doesn’t decrease the amount of it in the bloodstream but rather inhibits cellular uptake?

Wonder if this applies to exogenous thyroid hormones as well like you utilize Chase, cause if not that seems like the easy fix.

Interesting nonetheless, wish there was more research on this. Either of you guys utilized it in a diet and see any kind of connection? I would imagine it’s nothing to severe, since people seem to get shredded with and without Carnitine and I’ve never noticed a difference reported.

 

[cmryan]

I wonder if it has more to do with how Carnitine is used to control a thyroid storm. Maybe it’s effects only happen in that scenario?

I’m unsure and just spit balling

I wondered that as well after I read the first study linked above. Perhaps it only prevents thyroid uptake into nuclei in hyperthyroid patients. But that’s only a guess.

Wonder if @Type-IIx has any insight on this topic.

 

[Hyper-T]

My wife takes thyroid prescription synthroid and in the past has tried carnitine in hopes of its weight/fat loss properties and instead she gained a significant amount of weight and bloat in a short time, thus has avoided it like the plague since.

 

[Zamun]

My wife takes thyroid prescription synthroid and in the past has tried carnitine in hopes of its weight/fat loss properties and instead she gained a significant amount of weight and bloat in a short time, thus has avoided it like the plague since.

Facial bloat?

 

[KingOfSushi]

My wife takes thyroid prescription synthroid and in the past has tried carnitine in hopes of its weight/fat loss properties and instead she gained a significant amount of weight and bloat in a short time, thus has avoided it like the plague since.

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Interesting…

Facial bloat?

Facial swelling is a symptom of hypothyroidism, so it’s possible…

 

[Zamun]

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View this content on Instagram

Interesting…

Facial swelling is a symptom of hypothyroidism, so it’s possible…

I’m not a member of his site so can anyone sum it up? It appears fine as long as you’re not on any thyroid hormone?

 

[KingOfSushi]

I’m not a member of his site so can anyone sum it up? It appears fine as long as you’re not on any thyroid hormone?

Appears that even with normal thyroid production, too much L carn can cause an issue. Just keep the doses reasonable. What that dose is, I’m unsure… I’d bet meadows article on it has some more answers, but unfortunately I’m not a member of his website.

 

[nothuman]

There is evidence that too much carnitine can reduce thyroid function.
Doesn’t mean it will happen to everyone though.

 

[KingOfSushi]

There is evidence that too much carnitine can reduce thyroid function.
Doesn’t mean it will happen to everyone though.

Unlikely we will ever know where exactly that threshold is. It’s a shame it can’t be assessed easily through bloodwork by monitoring thyroid numbers, would make it a lot easier!

 

[buck]

My thyroid numbers are the same whether i am using carnitine or not.

 

[KingOfSushi]

My thyroid numbers are the same whether i am using carnitine or not.

Right, according to the information above the issue will not reflect in blood markers because it doesn’t change actual circulating levels, just it’s ability to get uptaken into the cells

 

[Hyper-T]

Facial bloat?

Fat gain and water retention.

 

[homonunculus]

I know this post is old, but it came up as a related post, so I thought I'd pop in.
This might address some of the above questions:

18. Gilgore SG, and DeFelice SL. Evaluation of carnitine--an antagonist of thyroid hormone. Clinical pharmacology report. J New Drugs 6: 349-350, 1966.

"The data demonstrate that triiodothyronine, as expected, clearly elevates the plasma NEFA. In the group given triiodothyronine plus carnitine, the NEFA [NOTE: NEFA = non-esterified / free fatty acids, representative of lipolysis] elevating effect of triiodothyronine was significantly inhibited. Also, the expected triiodothyronine-induced lowering of cholesterol and triglycerides was partially but significantly inhibited by carnitine.


Carnitine, in doses of 2 Gm. daily, significantly inhibited triiodothyronine-induced elevation of plasma nonesterified fatty acids and lowering of serum cholesterol and triglycerides. Carnitine also inhibited to some extent the expected triiodothyronine effects on serum tyrosine, BMR, and pulse rate."

-S