The 5 Best Carnitine Supplements On The Market

Why should you consider carnitine?

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The amino acid called carnitine isn’t technically essential, but many have found reasons to add it to their supplement regimen. It’s possible that it may have applications for exercise performance and longevity, but how do you decide which product to buy? We’ve looked at the top products on the market to bring you these excellent options.

Best Carnitine Supplements

Editor’s note: The content on BarBend is meant to be informative in nature, but it should not be taken as medical advice. The opinions and articles on this site are not intended for use as diagnosis, prevention, and/or treatment of health problems. It’s always a good idea to talk to your doctor before beginning a new fitness, nutritional, and/or supplement routine. Individual needs for vitamins and minerals will vary.

Best Overall

The very name Optimum Nutrition will bring comfort to many consumers. The makers of the most popular protein powder on the market, Optimum Nutrition is renowned for their quality control and their value — plus, these are tablets, not capsules, so they’re great for vegan diets.

Optimum Nutrition L-Carnitine 500mg Tablets
Optimum Nutrition L-Carnitine 500mg Tablets
Optimum Nutrition L-Carnitine 500mg Tablets

These carnitine tablets are easy to ingest, rigorously tested, and have added calcium.

Due to the company’s size and economy of scale, Optimum Nutrition makes pretty reasonably priced supplements. Each tablet provides 500 milligrams of l-carnitine tartrate and the tablets include 10 percent of the recommended intake of calcium.

Who Should Buy Optimum Nutrition L-Carnitine 500mg Tablets

  • Those in need of reasonably priced supplements.
  • Anyone who wants a reasonably strong dose of l-carnitine tartrate per serving.
  • People who need a slight boost to their calcium intake.

Who Shouldn’t Buy Optimum Nutrition L-Carnitine 500mg Tablets

  • Anyone who specifically wants a pure carnitine supplement.
  • People who want to dodge the added ingredients required to solidify a tablet.

The ingredients list includes silica, pharmaceutical glaze, stearic acid, and the disintegrant croscarmellose sodium. If you’re looking for a product that’s pure carnitine, it’s not this. Beyond that, this product provides a solid 500 milligram dose of carnitine backed by some calcium in an affordable package. This is a reliable overall pick.

[Related: Could Baking Soda Be The Best Workout Supplement You’ve Never Tried?]

Most Thoroughly Tested

Acetyl l-carnitine may cross the blood brain barrier more effectively than l-carnitine, and Nutricost provides some of the best supplements on the market. A big standout is that the product is third party tested, plus one little tub provides a considerable 500 servings of one gram each.

Nutricost Acetyl L-Carnitine (ALCAR) 500 Grams
Nutricost Acetyl L-Carnitine (ALCAR) 500 Grams
Nutricost Acetyl L-Carnitine (ALCAR) 500 Grams

This carnitine is third party tested and has no extra ingredients at all.

The other notable standout detail about Nutricost is they provide pure carnitine. There are absolutely no other ingredients are included — a huge boon for athletes who want to know exactly the amount of every supplement they’re consuming.

Who Should Buy Nutricost Acetyl L-Carnitine (ALCAR)

  • Those who appreciate extensive third-party testing for product purity.
  • Anyone who wants to avoid all ingredients that are not carnitine.

Who Shouldn’t Buy Nutricost Acetyl L-Carnitine (ALCAR)

  • Those who won’t be able to take all 500 servings before they expire.
  • Anyone who is unable to pallet the strong sour taste of pure carnitine.

Best For Athletes

NOW Sports offers one of the few carnitine supplements to be not only certified by Informed Choice — meaning the facilities are inspected for banned substances — but also Informed Sport, which means each batch of the product is tested. Many athletes only take products with these certifications, plus it comes in an unusual, tropical punch-flavored liquid form.

NOW Sports L-Carnitine Liquid 1000 mg
NOW Sports L-Carnitine Liquid 1000 mg
NOW Sports L-Carnitine Liquid 1000 mg

One of the few carnitine supplements certified buy Informed Sport.

This product also includes a dose of Vitamin B6, which may contribute to muscle retention. Carnitine is often maligned for its sour taste, but NOW Sports has naturally flavored (without added sugar) their beverage so it goes down easily.

Who Should Buy NOW Sports L-Carnitine Liquid

  • Those who want their supplements to undergo rigorous testing for banned substances and performance enhancers.
  • People who need a boost to their Vitamin B intake.
  • Folks who dislike carnitine’s sour taste and want supplements that are naturally flavored 

Who Shouldn’t Buy NOW Sports L-Carnitine Liquid

  • Anyone who is working with a tighter budget.

The major knock here is the price tag versus other competitive options on the market. However, if flavor is a high priority for you — a reasonable desire with frequently-taken supplements — then this should certainly be in consideration for you. The combo of carnitine in a tasty liquid with some Vitamin B to boot is a great call for pretty much any strength sports athlete.

[Related: Nutrition For Bulking: 10 Tips For Intelligent Muscle Gain]

Best Capsules

If you’re not after funky tasting powder, sweetened liquid, or filler-filled tablets, Life Extension makes a solid capsule that’s made from vegetable cellulose, so it’s free from animal products. In addition to using very few ingredients and providing 1.4 grams of carnitine per serving, it’s made in an NSF-registered facility, so it’s audited for quality and purity.

Life Extension Optimized Carnitine
Life Extension Optimized Carnitine
Life Extension Optimized Carnitine

Three types of NSF-certified carnitine that's encased in vegetarian capsules.

On top of being vegetarian friendly, this product packs three kinds of carnitine — acetyl l-carnitine HCL, acetyl l-carnitine arginate Di-HCL, and glycine propionyl l-carnitine HCL.

Who Should Buy Life Extension Optimized Carnitine

  • Those who appreciate a supplement that includes three kinds of carnitine.
  • Anyone who follows a vegetarian diet.
  • Folks who want their supplements manufactured in an NSF-certified facility.

Who Shouldn’t Buy Life Extension Optimized Carnitine

  • Anyone who doesn’t want to spend too much on supplements.
  • People who actively want to avoid silica (which is part of the ingredients that make the capsule).

Again, there isn’t much downside to many of the supplements on this list and Life Extension is no exception. The cost is knock here as there are less expensive options that consumers could turn to. On the whole, the trio of carnitine types in this supplement differentiates it from the field and vegetarians should be happy to have another viable option to choose from.

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Best For Buying In Bulk

Buy bulk, save cash, at least if you’re really taking a lot of carnitine. BulkSupplements is indeed the best way to buy up to a thousand servings of carnitine at once, and the quality is superb: it contains absolutely nothing but acetyl l-carnitine.

BulkSupplements.com ALCAR HCl
BulkSupplements.com ALCAR HCl
BulkSupplements.com ALCAR HCl

Pure acetyl l-carnitine that's unflavored and lab tested for purity.

Additionally, this carnitine supplement is tested both in house and by a third party to ensure quality, and it’s made in a facility free from major allergens.

Who Should Buy BulkSupplements.com ALCAR HCl

  • Anyone who needs to buy an extremely large quantity of carnitine all at once.
  • People happy to have their supplements thoroughly tested in house and by a third party for purity.
  • Folks looking for a pure carnitine supplement.

Who Shouldn’t Buy BulkSupplements.com ALCAR HCl

  • Anyone who doesn’t have a separate container large enough to store all the carnitine.
  • Those who can’t stand the sour taste of pure carnitine.

One of the recurring issues that arise with BulkSupplements is the lack of resealability of the bags supplements come in. That has the potential to endanger the freshness of the carnitine in the long term, so it is likely best to transfer the powder to a different container. Although that might be tedious, the trade off is getting a huge amount of product for a very low price per serving.

How We Decided Our Picks

Cost

Let’s start with the obvious decision influencer: price per serving. Of course, the less expensive products will rank higher on our list assuming the number of servings are equal. Like most supplements, buying in bulk can save a lot of coin, but it runs the risk of the product expiring before use. If you’re training for a powerlifting meet, calibrate how many servings you intend to take during your training period working on those squats and deadlifts, and try to line up with a product that offers that requisite number of servings.

Added Ingredients

Not all carnitine supplements are made equal. Of course, dosages will vary from product to product, but some products will also include other ingredients that may or may not be appealing to you. Some examples are added Vitamin B or calcium. If you’re in the market for boosts of the additional ingredient included, then you hit a nice little jackpot. However, if you’re not, there are plenty of pure carnitine options on the market. Just keep in mind that pure carnitine has a sour taste that may not be palatable for some users.

Form

This will come down to preference, but are you looking for a capsule, tablet, powder, or liquid? There are plenty of each on the market, each with their own pros and cons. Liquids are pretty easy to flavor without bogging down with a bunch of unnecessary sweeteners. Powders are usually the easiest way to get pure carnitine. Capsules and tablets might be easier or more efficient to consume for some customers but there is often a number of added ingredients added to make the tablet or capsule. If you have a preference for how you consume supplements, there are luckily options on the market likely to line up with that.

[Related: 10 Kinds Of Creatine And What They All Mean]

What Are the Benefits of Carnitine?

There are several reasons people might be interested in this supplement.

Longevity

Carnitine seems to help your mitochondria function and produce energy, and supplementing may improve mitochondrial function, which plays a role in immunity and longevity.(1)(2)

Fat Loss

Carnitine seems to help move more fatty acids into your cells to be used for energy, so there’s a popular theory that it can be useful as a weight loss supplement. Human studies are mixed, though — some analyses saw significant weight loss, particularly among obese or older adults, while others saw none.(3)(4) More research is needed, particularly in young subjects.

Better Muscle

Carnitine, particularly the form called L-Carnitine L-Tartrate, may help to reduce muscle damage experienced during exercise.(5)(6)(7) This research used doses of two grams per day. There’s also research suggesting that carnitine helps build and retain lean muscle among the elderly, but there’s not a lot of evidence on young, healthy folks.(8)(9)

Better Cardio Workouts

Two to four grams of carnitine per day has seen an increase in anerobic output, meaning short bouts of high intensity exercise.(10)(11)

Sperm Quality

High doses of carnitine — two or three grams daily — appears to increase sperm quality with regards to sperm morphology.(12)

Before You Buy

Keep these crucial things in mind before you purchase Carnitine. 

What Kind of Carnitine?

There are several forms of carnitine. L-carnitine is typical, but among others there’s also d-carnitine (which seems to limit your absorption of more usable carnitine, so it may be best to avoid), l-carnitine l-tartrate (perhaps most common in sports supplements as it absorbs quickly) and acetyl-L-carnitine, which is almost identical to regular carnitine but it’s been acetylated, so it may cross the blood-brain barrier more efficiently.(13)(14)(15)

Best Non-Supplement Form of Carnitine

The best dietary source of carnitine is meat and in particular beef, which provides 56 to 162 milligrams of carnitine per four-ounce serving.

Size of Dose

A pretty typical dosage is 250 to 500 milligrams twice per day, though a lot of the research mentioned above used two to three grams a day. It’s usually recommended to start with a lower dose and work your way up.

What To Pair With Carnitine

For your body to produce plenty of its own carnitine, it appears to be important to eat plenty of Vitamin C.(16)

Wrapping Up

Carnitine comes in many forms and can serve many purposes, but it’s of the utmost importance that you speak with a physician before making any additions to your nutrition and supplement regimen.

References

1. Iossa, S et al. Acetyl-L-carnitine Supplementation Differently Influences Nutrient Partitioning, Serum Leptin Concentration and Skeletal Muscle Mitochondrial Respiration in Young and Old Rats. J Nutr . 2002 Apr;132(4):636-42.
2. Rosca, M et al. Mitochondria in the Elderly: Is Acetylcarnitine a Rejuvenator? Adv Drug Deliv Rev . 2009 Nov 30;61(14):1332-1342.
3. Pooyandjoo, M et al. The Effect of (L-)carnitine on Weight Loss in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Obes Rev . 2016 Oct;17(10):970-6.
4. Broad, E et al. Effects of Four Weeks L-carnitine L-tartrate Ingestion on Substrate Utilization During Prolonged Exercise. Int J Sport Nutr Exerc Metab . 2005 Dec;15(6):665-79.
5. Kraemer, W et al. The Effects of L-carnitine L-tartrate Supplementation on Hormonal Responses to Resistance Exercise and Recovery. J Strength Cond Res . 2003 Aug;17(3):455-62.
6. Spiering, B et al. Effects of L-carnitine L-tartrate Supplementation on Muscle Oxygenation Responses to Resistance Exercise. J Strength Cond Res . 2008 Jul;22(4):1130-5.
7. Volek, J et al. L-Carnitine L-tartrate Supplementation Favorably Affects Markers of Recovery From Exercise Stress. Am J Physiol Endocrinol Metab . 2002 Feb;282(2):E474-82.
8. Malaguarnera, M et al. L-Carnitine Treatment Reduces Severity of Physical and Mental Fatigue and Increases Cognitive Functions in Centenarians: A Randomized and Controlled Clinical Trial. Am J Clin Nutr . 2007 Dec;86(6):1738-44.
9. Pistone, G et al. Levocarnitine Administration in Elderly Subjects With Rapid Muscle Fatigue: Effect on Body Composition, Lipid Profile and Fatigue. Drugs Aging . 2003;20(10):761-7.
10. Jacobs, P et al. Glycine propionyl-L-carnitine Produces Enhanced Anaerobic Work Capacity With Reduced Lactate Accumulation in Resistance Trained Males. J Int Soc Sports Nutr . 2009 Apr 2;6:9.
11. Wall, B et al. Chronic Oral Ingestion of L-carnitine and Carbohydrate Increases Muscle Carnitine Content and Alters Muscle Fuel Metabolism During Exercise in Humans. J Physiol . 2011 Feb 15;589(Pt 4):963-73.
12. Lenzi, A et al. Use of Carnitine Therapy in Selected Cases of Male Factor Infertility: A Double-Blind Crossover Trial. Fertil Steril . 2003 Feb;79(2):292-300.
13. Spasov, A et al. Effects of L-, D-, and DL-carnitine on Morphometric Parameters of Skeletal Muscle and Exercise Performance of Laboratory Animals Receiving Carnitine-Deficient Diet. Bull Exp Biol Med . 2006 Oct;142(4):458-60.
14. Traina, G. The Neurobiology of acetyl-L-carnitine. Front Biosci (Landmark Ed) . 2016 Jun 1;21:1314-29.
15. Trappe, S et al. The Effects of L-carnitine Supplementation on Performance During Interval Swimming. Int J Sports Med . 1994 May;15(4):181-5.
16. Steiber, S et al. Carnitine: A Nutritional, Biosynthetic, and Functional Perspective. Mol Aspects Med . Oct-Dec 2004;25(5-6):455-73.