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Many of my clients wish they had started taking L-carnitine sooner, especially those with weight loss or muscle-building goals.
This amino acid is crucial for exercise performance and recovery, but it's essential to choose the right type and quality to ensure effectiveness.
As a certified fitness coach, I teamed up with a dietitian and spent a few months working with different clients to come up with this list of the best L-carnitine supplements.
Are there L-carnitine supplements that not only meet your needs but also help you achieve your health goals? Read on and find out.
The Best L-Carnitine Supplements
- Best Overall L-Carnitine Supplement: Double Wood Acetyl-L-Carnitine
- Cheapest L-Carnitine Supplement: BulkSupplements ALCAR HCL
- Most Potent L-Carnitine Supplement: ProSupps L-Carnitine
- Best Carnitine Supplement for Athletes: NOW Sports Liquid L-Carnitine
- Best Fat Burning Supplement With Carnitine: Transparent Labs Fat Burner
- Best L-Carnitine Supplement for Bulking: NOW Sports Liquid L-Carnitine
- Best Liquid L-Carnitine Supplement: ProSupps L-Carnitine
- Best Stimulant-Free L-Carnitine Supplement: Double Wood Acetyl-L-Carnitine
Our Top L-Carnitine Supplements (April 2024)
1 - Double Wood Supplements Acetyl-L-Carnitine (Best Overall & Stim-Free)
- Dosage : 1,000 mg
Pros and Cons
Pros
- Flexibility in dosage so users can find the correct dose for them
- Made in the U.S.A. in a GMP-certified facility
- Third-party tested for quality transparency
- Boosted endurance and stamina
Cons
- Gelatin capsule not suitable for vegans/vegetarians
One of the things we liked most about Double Wood Supplements Acetyl-L-Carnitine is you have some flexibility with the dosage.
The base dosage is two 500 mg capsules, but per the manufacturer’s instructions, 2-4 capsules daily are optimal, not to exceed six capsules (3000 mg). More than 3000 mg per day increases the risk of adverse effects.
Drawing from our experience, the dosing range allows users to start small and work up to a larger amount if they feel it is suitable for them and well tolerated.
Our clients who volunteered to test this supplement reported feeling the benefits quickly and seeing significant increases in endurance and stamina during resistance training.
Double Wood Supplements offers a solid standalone Acetyl-L-Carnitine supplement to clear brain fog and increase stamina.
2 - Transparent Labs PhysiqueSeries Fat Burner Stim-Free (Best Discount for Bulk Purchase)
- Dosage : 750 mg
Pros and Cons
Pros
- The provided dose should work well for most athletes
- Includes other ingredients that may help with burning fat into energy
- Could provide a vitamin B12 boost as well
Cons
- Free shipping is only available on bulk orders
This fat-burning supplement from Transparent Labs is the one we favor most because it avoids the use of stimulants.
That means that you may be able to use it later in the day without risking a restless night.
As indicated by our tests, the 750 mg of Acetyl L-Carnitine per serving should also suit most athletes, as stronger doses might produce some side effects.
The only minor downside we’d highlight is that you only get free shipping on the bulk orders, but it’s totally worth it.
3 - ProSupps L-Carnitine (Most Potent & Liquid Option)
- Dosage : 3,000 mg
Pros and Cons
Pros
- One of the stronger options available to boost L-carnitine levels
- Many positive reviews about the flavor
- Should help you burn fat from stubborn areas
Cons
- You may need to start with a smaller dose to avoid negative effects
Some professional athletes that we’ve worked with have identified this as one of the most potent L-carnitine supplements available.
They also mentioned that it seemed to help them achieve more defined abs, which is an area where a lot of people tend to struggle with body fat.
Our team discovered through using this product that the flavor seems pleasant and doesn’t tend to leave an aftertaste.
Just keep in mind that if you’re starting to take L-carnitine, then this might be too strong at 3,000 mg per serving.
4 - NOW Sports Liquid L-Carnitine (Best for Athletes & Bulking)
- Dosage : 1,000 mg
Pros and Cons
Pros
- Comes in a liquid form to make a precise dosage measurement
- Claims to be the fastest to absorb and increase energy levels
- Tested for banned substances making it suitable for professional athletes
Cons
- The flavor is very strong, so you may want to water it down
Liquid L-Carnitine may be a great choice if you need to adjust your dosage for specific training sessions.
Many bodybuilders will adjust the intensity of their workouts, especially during a bulking phase. After putting it to the test, that’s when taking a high dose of L-carnitine may give you the right energy boost.
NOW sports claims that their L-carnitine formula is one of the fastest to absorb, and we’ve seen comments online that this seems to be true.
The only thing we noted is that it has an intense taste, so you may want to water it down a bit.
5 - MusclePharm Essentials Carnitine
- Dosage : 1,000 mg
Pros and Cons
Pros
- Uses a unique combination of different forms of L-carnitine
- Positive comments about boosted nitric oxide levels for better pumps
- Tested for banned substances which may be important for professional athletes
Cons
- Some people have reported minor stomach issues
The company claims to have the most powerful blend of propionyl L-carnitine, acetyl L-carnitine, and L-carnitine-L-tartrate. Apparently, this should help produce energy more efficiently.
Our clients tend to agree, and they feel they are getting better pumps after taking this L-carnitine capsules [1].
It might also be a good choice for competitive athletes who need to ensure their L-carnitine supplements don’t contain any banned substances.
We did notice a few online reviews where people mentioned feeling a bit bloated a short time after taking it.
6 - BRI Nutrition L-Carnitine Extra Strength
- Dosage : 1,000 mg
Pros and Cons
Pros
- Straightforward formula with no fillers or allergens
- Positive comments from bodybuilders going through a cutting phase
- Avoids stimulants, so the energy you get is real
Cons
- The capsules might be a bit large for some users
This product from BRI Nutrition seems to be well received because the company has kept the formula as simple as possible.
Who needs unnecessary fillers and allergens, right?
There are also no stimulants which some companies include to make it seem like you’re getting an energy boost rather than actually transforming fat into energy.
Based on our tests, the dose of L-carnitine also seems to have hit a sweet spot for most athletes, as it shouldn't result in any negative health effects.
The only thing we noted is that some people have struggled with the size of the capsules.
7 - Life Extension Optimized Carnitine
- Dosage : 1,400 mg
Pros and Cons
Pros
- Claims to be optimized for faster absorption
- Many comments about the positive workout performance
- Comes with a money-back guarantee for peace of mind
Cons
- The supplement capsules are a bit on the large side
Another one of our recommended L-carnitine supplements comes from Life Extension, which seems to be a good option for fast absorption.
It uses Acetyl L-carnitine HCL, Acetyl L-carnitine Arginate, and Glycine Propionyl L-carnitine to improve absorption of the body.
We heard from several people that they take it shortly before a training session and don’t have to wait long to feel it kicking in.
And if it doesn’t work for you, then you could get your money back as well.
The only thing we found is that the capsules are quite large compared to other products.
8 - BulkSupplements ALCAR HCL (Cheapest Option)
- Dosage : 600 mg
Pros and Cons
Pros
- Uses acetyl for increased production of energy
- Comes in a powder form to allow precise doses for your needs
- Positive feedback about boosted brain energy
Cons
- Measuring the small amount of powder can be difficult
BulkSupplements has chosen to focus on the ALCAR (Acetyl-L-Carnitine) type of L-carnitine, which apparently may help to produce energy for your muscles and brain as well [2].
This is something that many athletes underestimate, as gaining some focus and motivation may help you to get through a tough workout session more quickly.
Our clients like it as they are able to mix this L-carnitine powder into their pre-workout supplements as well.
While the powder makes it convenient, you may want to get some sensitive scales to measure precise amounts.
9 - MuscleTech Platinum 100% L-Carnitine
- Dosage : 500 mg
Pros and Cons
Pros
- Uses L-carnitine L-tartrate as a rapid-acting formula
- Doesn’t have any stimulants making it suitable for later in the day
- Online reviews highlight it might be helping with muscle recovery
Cons
- Might not be strong enough for performance athletes
This L-carnitine capsule is based on L-carnitine tartrate, which some believe to be the faster-acting type to take.
It might be a lower dose, but many reviewers have mentioned that it’s strong enough as it helps them avoid premature fatigue during training.
We also heard from clients who find they have a better recovery phase on the days they take it.
Now, if you’re doing some serious bodybuilding, then you probably need to look at stronger L-carnitine supplements.
10 - Nutricost Acetyl L-Carnitine
- Dosage : 1,000 mg
Pros and Cons
Pros
- Comes in powdered form to mix in with shakes and smoothies
- Claims to contain acetyl L-carnitine for better energy production
- 3rd party tested for purity and quality
Cons
- The flavors seem to be very sour
Here’s another L-carnitine powder that comes in powder form, which should allow you to get the dosage right for your muscle building and cutting phases.
Having that flexibility might improve your endurance, but it would also help you not waste any product.
We noticed that the flavor is very sour, so you may want to mix this L-carnitine powder with a shake or smoothie.
How We Tested the L-Carnitine Supplements
We implemented a rigorous testing process for the L-Carnitine supplements:
Selection Process
We began by sourcing a variety of L-Carnitine supplements from reputable brands, ensuring a diverse range of products for our testing.
Real-World Usage
Our team, consisting of fitness enthusiasts and nutritionists, used each supplement as directed over a specified period. This allowed us to gauge the product's efficacy, taste, mixability, and any potential side effects.
Ingredient Analysis
We delved deep into the ingredient list of each product. Supplements that contained high-quality, scientifically-backed ingredients were given preference. We also looked out for any potential allergens or harmful additives.
Performance Metrics
During our testing phase, we evaluated the impact of the supplements on workout performance, recovery, and overall energy levels. This helped us determine which products truly delivered on their promises.
Buyer’s Guide
1 - Check Out The Dosage And Type
While there isn’t a recommended amount of L-carnitine per day, it’s important to look at how much each product contains per serving.
A good average is about 750 mg, but you might get away with less depending on the different types of supplements used.
What do I mean? Some evidence suggests that acetyl L-carnitine and L-carnitine tartrate might work for faster muscle recovery, while propionyl-L-carnitine might provide better pumps [3].
2 - Look For Other Ingredients
You’ll find that some of these supplements only focus on L-carnitine supplements with no other ingredients. That’s great for stacking where you don’t want to end up with overlapping ingredients.
But many people might boost their health and wellness with supplements that also have some vitamins and other amino acids per serving. It’s definitely something to factor into your price comparison.
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3 - Compare The Price Tags
I usually work out how much pure L-carnitine supplements I need to take per day, and then calculate the price for that dosage on each product. This is important if you need an exact amount. But most people will probably be fine with a dose of about 750 mg.
Now, I wouldn’t recommend just going for the cheapest product. These often use processing and refining techniques that could break down the amino acid. As a result, you might get a lot less L-carnitine supplementation than what is advertised.
Benefits Of L-Carnitine
1 - Muscle Recovery
During my training sessions, I've personally felt the benefits of improved muscle recovery after incorporating L-carnitine into my regimen.
This aligns with a study I came across, which revealed that L-carnitine supplements might increase blood flow to muscle tissue [4].
Every muscle in the human body requires nutrients and oxygen. If you can get more blood into every muscle fiber, then it would make sense that any damage from exercise could be repaired faster.
Related Article: Tobey Maguire's Training and Diet Plan
“L-Carnitine assists in being better at fuel use, whether you are training or not. However, the best performance outcome does appear to be aiding in day-to-day recovery, especially from weight-training and sessions damaging to muscle, such as intense running.”
- Joe Beer, Health & Fitness Writer
2 - Reduce Fatigue
I remember those days when fatigue would hit me hard during workouts. But after introducing L-carnitine into my routine, I noticed a significant reduction in my fatigue levels. This personal observation is backed by studies suggesting that L-carnitine supplements help combat fatigue [5].
Now, to get the full benefit of this, you might need to experiment a bit with your intake timing.
You also need to know at what stage of your workout you usually start feeling your endurance levels drop. Maybe it’s 30 minutes into a session. You then want to do is take the L-carnitine product at a time when it would provide the best results to combat fatigue.
3 - Boost Endurance
During my intense workout sessions, I've always been on the lookout for ways to boost my endurance. When I started taking L-carnitine, I felt a noticeable improvement in my exercise performance, especially during those longer sessions. That doesn’t mean you should just take a huge amount, as your body might react negatively.
L-carnitine works by increasing blood circulation and delivering the right types of fatty acids into your muscle tissue.
That’s where it’s transformed into cell energy, and the more energy you have in your muscle tissue, the better you’ll be able to keep up the reps with more intense sets, as per NCBI [6].
4 - Weight Loss
According to NCBI, weight loss can be quite a challenge for people trying to get fit and for bodybuilders who need to trigger some fat loss in a cutting phase [7]. Combining the right diet with quality L-carnitine supplements and a solid training routine should help you achieve your weight goals more quickly [8].
If you want to lose weight faster, we have created a list of the best fat burners for men and the best fat burners for women.
“This valuable little molecule has been a staple in the bodybuilding and brain-hacking communities for years now, thanks to its ability to help you lose weight and power up your brain.”
- Spencer Brooks, Nutrition Writer at Bulletproof
5 - L-Carnitine and Aging
This amino acid derivative is primarily responsible for transporting fatty acids into the mitochondria, the cellular powerhouses, where they are converted into energy.
This energy production is essential for the proper functioning of various bodily processes, including muscle function, heart health, and brain function [9]. L-Carnitine has antioxidant properties that help protect cells from oxidative damage, a hallmark of aging.
6 - L-Carnitine and Vegetarian/Vegan Diets
Vegetarians and vegans can maintain adequate L-Carnitine levels through strategic dietary choices and supplements. While L-Carnitine is predominantly found in animal products like meat, there are plant-based sources to consider.
Avocados, tempeh, and certain nuts and seeds, such as almonds and sunflower seeds, contain some L-Carnitine [10]. Additionally, whole grains like wheat and rice offer small amounts.
Supplementation is also an option. Vegan-friendly L-Carnitine supplements derived from non-animal sources are available.
7 - L-Carnitine and Brain Health
Research suggests that L-Carnitine supplementation may enhance cognitive abilities and memory. Furthermore, its antioxidant properties help combat oxidative stress, a key contributor to neurodegenerative disorders like Alzheimer's and Parkinson's disease [11]. By reducing oxidative damage, L-Carnitine may support neuroprotection.
FAQs
Is L-Carnitine Bad for Your Heart?
No, L-carnitine isn’t bad for your heart. Some studies have even shown that the opposite could be the case. Evidence suggests that L-carnitine could play a role in reducing the risk of heart arrhythmia as well as developing angina.
Which Is Better Acetyl L-Carnitine or L-Carnitine?
Acetyl L-carnitine is better than L-carnitine for the human body, according to scientists. It’s believed to be easier for your stomach to absorb, which would make it the faster-acting form. Also, some research suggests that it crosses the blood-brain barrier more easily.
Does L-Carnitine Cause Hair Loss?
No, L-carnitine doesn’t cause hair loss. There’s actually some evidence that it could increase the blood supply to hair follicles and deliver more nutrients to increase hair growth. It’s one side effect that many users have reported after several weeks of use of the best L-carnitine supplements.
Does L-Carnitine Have Side Effects?
Yes, L-carnitine can have side effects in rare instances when it's ingested in heavy doses. These might include stomach cramps, nausea, heartburn, and diarrhea. But in most cases, these symptoms will disappear as soon as you reduce the dose or stop taking L-carnitine supplements altogether.
Is L-Carnitine Good for Weight Loss?
Yes, L-carnitine is good for weight loss. It plays a crucial role in transforming stored body fat into the type of energy that different cells in your body need.
That doesn't make it a miracle pill for dealing with weight issues, but combined with a good diet and exercise routine, the best L-carnitine supplements should help.
Can You Take L-Carnitine on an Empty Stomach?
Yes, you can take L-carnitine on an empty stomach. Many dietitians would recommend this approach, as doing so would make it easier for your stomach to digest and absorb the supplement. Just check for any signs of adverse effects.
Our Verdict on Best L-Carnitine Supplement
Whether you want to improve endurance and stamina or clear a bit of brain fog, this supplement allows you a little wiggle room in the dosage to tailor it to your needs and tolerance.
Double Wood Supplements has a strong brand reputation and stands behind the quality of its ingredients with transparent third-party testing.
Our clients and countless positive online reviews report a significant boost in stamina, endurance, and cognitive function.
These are the reasons we throw our support behind Double Wood Supplements Acetyl-L-Carnitine and encourage you to give it a try.
Our #1 Recommendation
Double Wood Supplements Acetyl-L-Carnitine (Best Overall & Stim-Free)
Rated With Total Shape's Scoring System
- Flexibility in dosage so users can find the correct dose for them
- Made in the U.S.A. in a GMP-certified facility
- Third-party tested for quality transparency
- Boosted endurance and stamina
- Get the BEST PRICE until the end of April
- Gelatin capsule not suitable for vegans/vegetarians
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Thank you so much! The buyer’s guide section is definitely helpful.