Mattgainz69
Active Member
Got some injectable l carnitine. 500 mgs. Is it worth it to only take pre workout or do I need to take it everyday. Also does it contribute to hair loss?
Is injectable l carnitine worth it for work out days only
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manifesto
Well-known member
Y
yeah I ran it everyday for years...pretty minimal difference if I look back, and alot of money spent
Mattgainz69
Active Member
Will it have any affect on my thyroid? Had hypothyroidism when I was hunger. Put on levothyroxine. My current dr thought I never really needed it in first place so took me off and levels have been fine but not sure if the l carnitine could put me back into hypo? And heard it wouldn't show up on blood work.
Smont
Legend
From my understanding it only changes symptoms, it does not affect circulating thyroid levels
Chuck Diesel
Are you Diesel?
I haven't read these replies but you don't have to inject L-Carnitine, it works find orally. Acetyl-L-Carnitine is can make some ppl's androgen receptors more sensitive. L-Carnitine L-Tartrate is for fat loss, not for androgen receptors. There is a difference.
manifesto
Well-known member
What up Chuck?!?! Man, one the of the OGs up in here!!
I thought i remember the bioavailabilty only being around like 14% or something like that....which is why peeps inject it
Smont
Legend
It really depends on what effect you're after
Chuck Diesel
Are you Diesel?
Hey bro,
Let me explain this from a different angle, because comparing the oral dose to the injected dose doesn't mean you're getting 5x or 10x more carnitine into the muscle (not that you implied that, but I should have said its uptake to the muscle is more important to the delivery, not assuming injecting takes a 14% bio to say 80-90% bio to the muscle.
Injecting L-carnitine does not necessarily deliver more useful carnitine to skeletal muscle. Human studies have shown that dramatically increasing plasma carnitine does not necessarily increase muscle carnitine unless insulin is elevated at the same time.
For example:
1. IV L-carnitine during exercise: In a randomized crossover study in healthy subjects, IV L-carnitine dramatically increased plasma carnitine during exercise, but muscle carnitine did not increase. It also didn't significantly increase fat oxidation or change muscle glycogen use or lactate accumulation.
So simply putting a lot more carnitine into the bloodstream didn't mean more carnitine entered the muscle or produced a greater metabolic effect.
2. IV L-carnitine + elevated insulin: In another study, researchers infused L-carnitine for 5 hours. Again, increasing plasma carnitine by itself did not significantly increase muscle carnitine. However, when carnitine was combined with elevated insulin, muscle carnitine increased by approximately 12%.
So the important limitation isn't just getting L-carnitine past the digestive system and into the blood. Getting it from the blood into skeletal muscle is another step, and insulin is an important role in that transport.
That's why saying injectable L-carnitine is "X times more effective" simply because oral L-carnitine has low bioavailability isn't supported by these studies. Injection clearly produces much higher plasma availability, but higher plasma carnitine does not automatically equal proportionally higher muscle carnitine.
https://pubmed.ncbi.nlm.nih.gov/8004884/
(IV carnitine caused dramatic changes in plasma carnitine, but did not increase muscle total carnitine or alter measured fuel metabolism during exercise).
(Eight healthy men received 5 hours of IV L-carnitine. With fasting-level insulin, muscle total carnitine essentially didn't change (22.4 → 22.7 mmol/kg dry muscle). With high insulin, it increased from 22.0 → 24.7 mmol/kg, about 13%)
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So preworkout works, only if you have just had a preworkout carb meal per se.