8 Best L-Carnitine Supplements (2024) Reviewed and Compared
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Posted by
David Rosales
L-Carnitine is an incredibly popular and well-researched supplement.
It’s often called an amino acid, but chemically, this isn’t exactly true. It’s more like if a B vitamin and an amino acid had offspring. And that offspring helped you burn fat and recover faster.
Like B vitamins, It plays an important role in energy production. Specifically though, l-carnitine shuttle fatty acids into the mitochondria of the cell, where the fat can get burned as fuel.
This leads to increased energy and more fat burning.
For This Product, Go Vegan
We don’t typically rank products higher just because they’re vegan, but anything with amino acids is an exception.
That’s because many non-vegan amino acid products are sourced from what’s called “animal by-product.” This is code-word for the absolute scraps and lowest-quality parts of animals, like rotting bones, bird feathers, and more.
I have still included some non-vegan products, but keep in mind what “vegan” means in this case. Vegan means it’s derived from plant sources, which are generally of higher quality.
For more of the benefits of l-carnitine, you can read below, but let’s get right to the best l-carnitine products on the market.
Best L-Carnitine Supplements
*Note: We do have affiliate links throughout this article, which means we receive a commission if you purchase from any of our links. This supports our mission to bring complicated health and fitness info in an entertaining package. And it keeps us from putting up annoying things like banner ads. Those suck.
Best Pure L-Carnitine: Kaged L-Carnitine
Best Carnitine For Weight Loss And Performance: Kaged Clean Burn Powder
Best Carnitine For Cognition: Double Wood Acetyl-L-Carnitine
1) Kaged Clean Burn with Apple Cider Vinegar (best for fat loss and performance)
Most people, including probably you, looking to take a carnitine supplement, are looking to support fat loss. While l-carnitine helps shuttle fatty acids to get used as energy, on its own, it hasn’t been shown that it can really stimulate fat loss.
That’s why for this goal, we recommend a comprehensive fat burner product, which includes l-carnitine as part of a complete formula.
Kaged Clean Burn is a health-first fat burner with 1500mg of Carnipure® l-carnitine l-tartrate, alongside other powerful fat loss ingredients like CapsiMax, ChroMate chromium, organic guayasa, and more. They even include apple cider vinegar in their formula.
This product contains 166mg of organic caffeine. While caffeine can support thermogenesis, this means you won’t want to take it in the evening.
The orange mango flavor is delicious, and I absolutely love this product as an intra-workout drink or to sip on while I do cardio. The caffeine and other ingredients support exercise performance while supporting healthy weight loss.
It’s non-GMO, suitable for vegans, gluten-free, and Informed-Sport Certified so it’s safer for athletes.
If you’re looking to support weight loss with a supplement that has more than just l-carnitine, then look no further than Clean Burn.
2) Kaged L-Carnitine (best pure l-carnitine product)
Kaged is known for only using premium, quality-sourced products, even if it means sacrificing profit margins. Their l-carnitine is no exception.
First, their product uses a patented form of l-carnitine l-tartrate called CarniPure®, which has been shown in many studies to improve recovery and reduce soreness.
Carnipure® is only manufactured by a unique production process by the Swiss life sciences company Lonza. Because of the patented production, they’re able to make the purest form of l-carnitine l-tartrate with the fewest impurities.
Basically, you get the most for what you pay for, without any impurities or unwanted ingredients.
Kaged’s l-carnitine comes in capsules that are easy to make a part of your pre-workout stack.
They’re also informed-sport-certified, vegan, and non-GMO. It contains no fillers.
Every bottle comes with 250 veggie capsules with 500mg of l-carnitine. While the serving size is 500mg, for best results, take 3-4 capsules per day.
If you’re looking for a pure, simple l-carnitine product at a great price, then Kaged CarniPure® is the product for you.
3) Double Wood Acetyl-L-Carnitine
This product from Double Wood is a simple, high-quality, great value ALCAR product.
As we mentioned, acetyl-l-carnitine is the only form of l-carnitine that has been shown to make it through the blood-brain barrier.
Therefore, it has unique benefits for brain function and slowing cognitive decline. More specifically it can support brain metabolism, so it’s ideal “brain fuel.”
It contains acetyl-carnitine and nothing else.
Double Wood is known for their purity, and they display the lab results of every batch of their products.
Each bottle contains 150 capsules with 500mg of acetyl-l-carnitine. It’s non-GMO, gluten-free, and proudly made in the USA.
It also comes with a 60-Day Money Back Guarantee, so if it’s not for you, they take on the risk.
Double Wood supplements is a great brand with an array of single-ingredient supplements.
4) MRM Acetyl-L-Carnitine
MRM Acetyl-l-carnitine is a similar product. It’s not as good a value, but it is suitable for vegans.
You can get 60 capsules with 500mg of ACL for just 9 bucks.
5) PureBulk L-Carnitine (best value)
If you’re looking for the best cost-per-gram deal on the market from a third-party trusted brand, then PureBulk has what you’re looking for.
They even have bulk purchases of l-carnitine, l-carnitine l-tartrate, and acetyl-l-carnitine.
With a 100-gram bag for $16, you can’t beat the deal.
However, it does come as an unflavored l-carnitine powder, and it’s a bit bitter.
I’m a wuss, so what I do in these types of situations is mix them into smoothies or other pre-workout drinks, and that works fine.
6) Doctor’s Best L-Carnitine Fumarate
This product is a bit more expensive for the serving. While it has 855mg, only 500mg of this is actually l-carnitine because it’s a form called l-carnitine fumarate.
That said, l-carnitine fumarate also has some differences between other forms.
L-carnitine fumarate is specifically used for heart and cardiovascular health, and it has been studied at length with various degrees of success.
This product is also vegan, and uses a patented form of l-carnitine fumarate, and is manufactured in an FDA-approved facility, so it’s also of the highest quality.
7) Nutrex Research Liquid L-Carnitine
This liquid product comes in free-form l-carnitine. The taste, like all other liquid l-carnitines, is not bad, but it is kind of like “taking your medicine.” There are three different flavors. Trust me, they’re all average at best. But this isn’t a protein powder, there isn’t much room to play with taste.
Onto the more important stuff. Every bottle has 48g of l-carnitine total. If you average this out per cost, it’s more expensive than most of our other options.
But, if you prefer the liquid option, then this is one of the simplest and highest quality.
8) Jarrow Formulas L-Carnitine
Jarrow’s product is also free-from. Every capsule contains 500mg of l-carnitine. It’s also a vegan product, which I’m a big fan of for this class of products, where the sourcing of amino acids can get questionable and of lower quality.
As usual, Jarrow has a solid product, and this is a vegan option as well.
What Are Other Benefits of L-Carnitine?
The fat-burning link makes sense both mechanistically and anecdotally among thousands of users, but right now the evidence is lacking that there’s a direct link.
So if you’re wondering if l-carnitine supports weight loss, the answer is maybe, and only in conjunction with a quality training program and a diet with a caloric deficit. That’s why our top choice is a more comprehensive product, Kaged Clean Burn.
However, l-carnitine has many other benefits.
Improvement in Liver Disease and Function
Many studies show that l-carnitine reduces ammonia levels, which is a marker of liver function.
So l-carnitine can be an effective supplement if you have liver problems (very common among bodybuilders who take certain performance-enhancing drugs).
For liver function, TUDCA is another popular supplement, and you can see our list of the best TUDCA supplements.
Improved Sperm Quality and Rate of Pregnancy
This meta-analysis looked at a bunch of studies and found that 2 grams per day of l-carnitine (a modest, normal dose) helped infertile men.
Waist Circumference for Those With Metabolic Syndromes
While the fat loss research on otherwise healthy, very active people is shaky, for those with metabolic syndromes (diabetes, obesity, high blood pressure), l-carnitine does seem to promote fat loss. It’s a popular ingredient in “fat burner” supplements, and may help you lose body fat in conjunction with other ingredients, diet, and exercise.
However, this is NOT a magic weight loss supplement. (No supplement is magic.)
Reduced Soreness
Researchers found this benefit when studying a specific, patented form of l-carnitine, CarniPure®. So if you want to use l-carnitine to reduce soreness and enhance exercise recovery, look for products that contain CarniPure® l-carnitine.
Don’t worry, we will highlight this on our list.
One of the theories for why this is the case is because it improves how you use your fuel (ATP) while you train, and may also increase blood flow.
For this reason it may fit well in a pre-workout stack with an ingredient like l-citrulline.
Improved Cognitive Function
Increases in cognitive function from l-carnitine specifically come from a form of l-carnitine called acetyl l-carnitine.
For example, this meta-analysis discusses acetyl l-carnitine’s potential for fighting dementia and other forms of cognitive decline.
This is because acetyl l-carnitine can cross through the blood-brain barrier, as has been examined in several studies like this one.
However, acetyl-l-carnitine hasn’t demonstrated many of the other benefits, like fat loss potential or increased muscle recovery compared to l-carnitine l-tartrate.
With all of this said, here are the best l-carnitine supplements on the market.
There are tons of comprehensive products that include l-carnitine in them. Those didn’t make our list. Because l-carnitine often comes as capsules, it’s simple to take a pure product, and then add it to your supplement stacks based on your specific goals.
Especially because making a decision about l-carnitine supplementation is already complicated enough as it is. You have three different forms:
- L-carnitine l-tartrate
- Acetyl-l-carnitine
- Free-from l-carnitine
These all have differences, depending on your goals. We cover the research on these differences after the products.
And, they’re available in powders, capsules, and liquids. Let’s be honest with ourselves, capsules are almost always easier. Sometimes you pay for the convenience, though, so that’s also reflected in our ranking. If it’s a powder, it better taste delicious.
Support Energy Production
You may notice that l-carnitine supports your energy levels. While this link isn’t direct, because it shuttles fatty acids into the bloodstream. To make an analogy, this amino acid carries would to the furnace where it can then get burned.
Are There Any Side Effects of L-Carnitine?
Acetyl-l-carnitine has in a few instances worsened the symptoms of bipolar disorder. Remember, AlCAR interacts with the brain, and bipolar is a complex disorder.
It has also interfered with thyroid hormone function at high doses.
The more common side effect is stomach discomfort and nausea. Many people seem to tolerate l-carnitine better if they have something in their stomach.
When Should I Take L-Carnitine?
This partially depends on the form you take. If you use l-carnitine l-tartrate for athletic performance and recovery, you can take it either pre-workout or post-workout.
In fact, it goes great with a complete pre or post-workout stack. It’s great with your pre-workout, your creatine supplement, or your protein shake.
If you take acetyl-l-carnitine for brain performance, take it 30 minutes to an hour before your work or creative session.
For a complete fat-burner product like Clean Burn Powder, it’s great in the morning or before a cardio session.
What’s the Best Form of Carnitine?
This question depends on your goals.
L-Carnitine L-Tartrate is the best form for using fat as fuel and supporting recovery. In particular, look for Carnipure®, a patented high-grade form.
If your goal is cognition support, Acetyl-l-Carnitine is what you’re looking for, since this form may cross the blood-brain barrier.
For cardiovascular support, L-carnitine fumarate is the most well-researched form.
When Should I Take If My Goal is to Burn Fat?
Most “fat burner” products out there aren’t high-quality and packed with stimulants. For two options that include l-carnitine with a complete blend AND are stim-free, check out Kaged Clean Burn and Transparent Lab Stim-Free Fat Burner.
Is Carnitine Deficiency Common?
Not really. However, it does happen in a few instances. First, some people genetically have a carnitine deficiency. Second, cancer patients undergoing chemotherapy may have a deficiency, as investigated in this study.
For the vast majority, l-carnitine isn’t out of medical necessity. Rather, it’s to support your workout performance and physique.
Disclaimer: We’re not doctors, and we don’t play doctor on the internet. Talk to your healthcare provider before taking any dietary supplement, including l-carnitine.
