If you’ve been taking men’s health or bodybuilding products for quite some time now, you might have come across L-Carnitine. It is, afterall, a supplement that’s involved in a wide array of bodily functions so chances are you’ve at least heard of it.
If you’re looking for more information and an intellectually opinionated take on L-Carnitine and how it impacts male health and testosterone, then you’ve come to the right place because in today’s research review, that’s exactly what we’re going to be all about.
WHY TEST BOOSTER SUPPLEMENTS USE L-CARNITINE
When you think about L-Carnitine, the first though that comes to mind is that it is an amino acid and as an amino acid, it’s likely common knowledge to exercise veterans that it is a building block of protein. However, there are so much amino acids in the market that you might be asking yourself, “what makes L-Carnitine so special?” Well, let me help you uncover the answers to that question but first, let’s further define L-Carnitine.
What is L-Carnitine?
Otherwise known as simply Carnitine, it is a substance that helps the body turn fat into energy. Our bodies are able to make its Carnitine in the liver and kidneys where it is then stored in skeletal muscles, sperm, heart, and brain. However, there are cases when our bodies don’t make enough of L-carnitine, thus the need for external sources such as supplements and foods including red meat where it is found in the highest concentrations. The reason why it was named “Carnitine” was also because the Latin word “Karne” means meat.
L-Carnitine is also an antioxidant that helps battle the negative effects of free radicals.
Strictly in terms of testosterone boosting, L-Carnitine seems to be able to bring back healthy levels of testosterone while also preventing it from decreasing.
In bodybuilding, it helps enhance physical performance by neutralizing stress and enhancing energy levels. For more intricate details, let’s get to the research part of this review.
STUDIES ON L-CARNITINE SUGGEST:
Guard against oxidative stress
Exercise is healthy, no doubt, but it is also interpreted by our bodies as stress. Moreover, with chronic stress, our testosterone levels tend to take a dip which obviously isn’t what we men want.
I found a research that aims to examine the effect of L-carnitine supplementation on exercise performance and blood redox status at rest and after exercise. The research was conducted by administering either L-carnitine or a placebo to hemodialysis patients over an 8 week period. The participants were then asked to perform an exercise until they felt exhausted. Results of the L-carnitine group versus the placebo group are as follows:
- Blood carnitine proportionally increased with L-Carnitine supplementation
- Improved time to fatigue by 22%
- Reduced post exercise lactate by 37%
- Lowered sub-maximal heart rate and respiratory quotient
- Increased oxidized glutathione (2.7-fold at rest, 4-fold postexercise) and glutathione peroxidase activity (4.5% at rest, 10% postexercise)
- Decreased malondialdehyde (19% at rest and postexercise) and protein carbonyl concentration (27% at rest, 40% postexercise)
According to the results of the research, “L-carnitine supplementation may be effective in attenuating oxidative stress responses, enhancing antioxidant status, and improving performance“.
Combining both studies, it could be said that L-carnitine is able to guard testosterone and enhance physical performance from the otherwise negative effects of stress.
Normalize low testosterone
A research was done to evaluate the radioprotective role of L-carnitine against testicular damage induced by irradiation. The study was done by exposing adult male mice to whole body irradiation for 10 days with either the absence and/or presence of L-Carnitine at a dose of 10 mg/kg of body weight per day. The research measured quite a lot of things but those that are significant to this article are as follows:
- Irradiation decrease serum testosterone whereas L-Carnitine increased serum test compared to controls
- Irradiation caused a 43% level of sperm abnormality while the presence of L-Carnitine reduced these abnormalities to 12%
- Irradiation induced severe tubular damage but was reduced with L-Carnitine treatment prior to irradiation
Additionally, there is a another research that relates to the benefits of L-Carnitine that are shown here. This research was done to determine whether carnitine deficiency was independently associated with low free testosterone levels in male hemodialysis patients. Blood chemistries were taken including serum levels of free testosterone and carnitine. The results are the following:
- free testosterone levels were significantly lower in the hemodialysis patients compared to the healthy controls
- L-Carnitine was correlated with “free” testosterone levels
The study was then concluded with the researchers saying that “decreased carnitine levels were independently associated with low free testosterone“.
As you can see with both studies, their experimental subjects had lower levels of testosterone compared to their healthy counterparts. Combining both studies, L-Carnitine supplementation was able to increase levels of both total and “free” testosterone with added protection to our sperm. The results of these studies may be suggestive of the benefits that L-Carnitine can have on older men who are already suffering from lower levels of testosterone.
Enhance muscle growth and recovery
A research was done to to examine the influence of L-carnitine L-tartrate (LCLT) supplementation on anabolic hormone response and growth factors in response to acute resistance exercise. Among the hormones that were measured are IGF-1, IGFBP-3, growth hormones, and of course testosterone.
The research was conducted by having the volunteers supplement on 2 g of LCLT per day for 3 weeks. Blood samples were then collected for 6 consecutive days. After a 1 week “washout period”, the same volunteers were then asked to consume the “other supplement” (which I believe to be a placebo) for another 3 weeks following the same experimental protocol. The results of the research are found below.
- Growth hormones, IGFBP-3, and testosterone were all increased but this was to be expected with exercise
- A reduction in the amount of exercise-induced muscle tissue damage was observed with LCLT supplementation during the recovery period
As stated by the researchers themselves, “No other direct effects of LCLT supplementation were observed on the absolute concentrations of the hormones examined, but with more undamaged tissue, a greater number of intact receptors would be available for hormonal interactions“.
This means that while LCLT doesn’t seem to have any direct influence on testosterone boosting, it manages to enhance the anabolic effects of testosterone by minimizing the amount of muscle damage, thereby increasing the number of androgenic receptors that can interact with testosterone. Which by the way, also makes it a good supplement for recovery.
How Do I Take L-CARNITINE?
L-Carnitine has quite a number of forms. As such, there are also quite a few ways to take it and reasons as to why that form is the best for your intended purpose.
Let’s start with the basic form which is just plain L-Carnitine. This form is what you find in red meat and other protein rich foods. It is also the least bioavailable form which typically makes it the worst choice for supplementation.
Next we have L-Carnitine L-Tartrate which is a combination of Carnitine and Tartaric acid. If your goal was to use L-Carnitine for bodybuilding and exercise, this is what you want to be taking because it increases ATP production via fatty acid oxidation, leading to more energy and lean muscle. A dosage of 1,000 – 4,000 mg should be fine but if you want optimal effects, the higher end dosages of 3,000 – 4,000 mg divided into 3 servings is what I suggest.
On the other hand, if you aren’t an active man, Acetyl-L-Carnitine (ALCAR) might be the better choice for you. The combination of L-Carnitine and an acetyl chain makes it easier for this supplement to cross the blood-brain-barrier which makes it a great choice for nootropics. A daily dosage of 630 mg – 2,500 mg should suit you fine.
Based on the researches that I’ve referenced to, L-Carnitine doesn’t seem to boost testosterone levels beyond normal levels. Personally though, I think it still does have a place in testosterone boosting stacks.
Specifically for testosterone boosters that’re geared towards bodybuilding and athletics, L-Carnitine looks to be quite beneficial. Active men are at risk for falling victim to chronic stress and physical plateaus due to their affinity to exercise. L-Carnitine can help with that by guarding against chronic stress and maintaining healthy levels of testosterone post exercise.
Another demographic that looks to testosterone boosters for help are the more mature men who’re at or on the verge of lowered levels of testosterone. As demonstrated by a couple of studies above, L-Carnitine was able to normalize hormonal levels of men who’re suffering from low test.
TESTOSTERONE BOOSTERS THAT USE L-CARNITINE
- Anotest – A powdered testosterone booster that uses L-Carnitine L-Tartrate (LCLT) dosed at 1,466 mg
- Testogen XR – A product of Ronnie Coleman himself, this supplement also uses LCLT at 1000 mg
- Activate T Red – Has Acetyl L-Carnitine as it’s top ingredient in its Neuro-Cerebral Focus Blend
- Test Drive – A hybrid testosterone booster using L-Carnitine HCl
- APE – Uses GlycoCarn® which is a branded form of Glycine Propionyl-L-Carnitine Hydrochloride