Reviews and Information for Acetyl-L-Carnitine
Acetyl-L-Carnitine Supplements
Learn how to find the best acetyl-L-carnitine supplements. We purchased and tested the ingredients in acetyl-l-carnitine products and rated their quality. Find out which ones passed our test and why.
Acetyl-L-Carnitine Supplements ReviewSearch term may appear only in full report available to members. Join now for full access.
Clinical Update
4/19/2024
Acetyl-L-Carnitine for Nerve Pain?
Is acetyl-L-carnitine recommended to reduce nerve pain in people with diabetes? Find out in the What It Does section of our Acetyl-L-Carnitine Supplements Review.
Also see: Do any supplements, like Nervive, help with nerve pain, like sciatica, diabetic neuropathy or postherpetic neuralgia?
Clinical Update
8/28/2020
Acetyl-L-carnitine + Alpha-Lipoic Acid for Lowering Blood Pressure?
We were recently asked if taking a combination of acetyl-L-carnitine and alpha-lipoic acid can help lower blood pressure. Find out what research shows in the What It Does section of the Acetyl-L-Carnitine Supplements Review. Also see our answer to the question: Which supplements can help to lower blood pressure?
CL Answer
Does Qualia Mind boost memory and mental function and is it worth cost?
Learn about the ingredients in Qualia Mind, whether or not we think the formula works and is safe, and if we think it's worth the cost.

CL Answer
Is there a danger in taking lecithin or phosphatidylcholine? I heard that they may increase the risk of heart attacks.
Lecithin, phosphatidylcholine and choline - Learn more about the potential link between them and cardiovascular disease.

CL Answer
What is Pycnogenol, does it work, and is it the same as other pine bark extracts?
Learn more about Pycnogenol, including evidence from clinical studies on blood clots, osteoarthritis, cognition, vision, tinnitus, and the skin and safety.

Clinical Update
4/14/2013
Concern Over Carnitine Causing Cardiovascular Disease
Intake of L-carnitine from supplements (and from red meat) may foster atherosclerosis (hardening of the arteries), according to new research. Once ingested, L-carnitine is converted in some people to a compound which reduces the normal clearing of cholesterol from arteries.
For more details, see the updated reviews of B Vitamin Supplements & Energy Drinks and Protein Powders, as some of these products contain L-carnitine. The Acetyl-L-Carnitine Supplements review has also been updated because acetyl-L-carnitine is chemically similar to L-carnitine, suggesting a potential concern.
Clinical Update
8/22/2024
Leg Cramps and Carnitine
Does taking L-carnitine or acetyl-L-carnitine reduce leg cramps? See what research suggests in the What It Does section of our Acetyl-L-Carnitine Review.
Also see: Do any supplements, foods, or oils help reduce muscle pain, muscle cramps, or nighttime leg cramps?
CL Answer
Which supplements help with erectile dysfunction?
Supplements for erectile dysfunction. Find out which supplements can help with ED, including ginseng, L-arginine, and maca.

Product Review
Ginkgo (Ginkgo Biloba) Supplements Review
Choose the Best Ginkgo Biloba Supplement. Finding Real Ginkgo Isn't Easy — 60% Fail ConsumerLab's Tests of Quality.

CL Answer
Are supplements such as Thyroid Care Plus helpful for hypothyroidism? Can supplements worsen thyroid function? And what is nascent iodine?
Learn about supplement ingredients such as iodine, selenium, zinc, acetyl-l-carnitine, ashwagandha and guggul used for thyroid conditions and find out if they are beneficial. Also learn why ingredients such as alpha-lipoic acid, soy, resveratrol, quercetin may impair thyroid function.

News Release
March 11, 2019
Best NAC (N-acetyl cysteine) Supplements Identified by ConsumerLab
White Plains, New York, March 11, 2019 — NAC (N-acetyl cysteine) supplements are promoted for many uses, including "liver support," "immune support," and reducing symptoms of the flu and flare-ups of chronic bronchitis.
News Release
December 09, 2014
Round-up of Recent Product Tests by ConsumerLab.com -- Results for B Vitamin Supplements & Energy Drinks, Garlic, NAC (N-acetyl cysteine), Iron and Omega-7 Fatty Acids
White Plains, New York, December 9, 2014 — In recent months, ConsumerLab.com has published test results for a variety of popular supplements, including B vitamins supplements and energy drinks, NAC (N-acetyl cysteine), iron and garlic. In addition, ConsumerLab.
CL Answer
Which supplements or foods can help lower cholesterol and keep my heart healthy? Are there any to avoid?
Information about heart health supplements & vitamins that help with cholesterol, including sterol esters, CoQ10, and vitamin D, and which may be bad for the heart, like calcium.

CL Answer
Do any supplements, like Nervive, help with nerve pain, like sciatica, diabetic neuropathy or postherpetic neuralgia?
Find out which supplements for nerve pain, including fish oil and alpha-lipoic acid, are effective for sciatica, diabetic neuropathy, or postherpetic neuralgia.

CL Answer
Body Odor: Supplements & Foods That May Help, or Make It Worse
Some people with adequate personal hygiene still experience body odor. Learn if taking supplements such as activated charcoal, champignon extract, copper chlorophyllin, L-carnitine, N-acetyl cysteine (NAC), or other ingredients might help or make body odor worse.

Clinical Update
9/28/2021
Supplements During Chemotherapy?
If you are getting chemotherapy, experts now recommend avoiding acetyl-L-carnitine. Also, see what they have to say about using alpha-lipoic acid, vitamin B-12 and vitamin E.
Clinical Update
1/28/2018
L-Carnitine Caution
A study in which L-carnitine was given to women during chemotherapy had a surprising result: It worsened side effects. Get the details in the Concerns and Cautions section of the Acetyl-L-Carnitine Supplements Review.
Clinical Update
12/02/2018
Carnitine Heart Risk?
Supplementing with L-carnitine can raise blood levels of TMAO which can potentially advance atherosclerosis. However, the science is not clear, as suggested by a recent study. Get the details in the L-Carnitine section of the Acetyl-L-Carnitine Supplements Review.
Clinical Update
6/21/2022
Best Form of Carnitine?
Which form of L-carnitine is best absorbed? Find out what research shows in the What to Consider When Buying section of our Acetyl-L-Carnitine Supplements Review.
Clinical Update
4/08/2022
Cardiovascular Concerns With L-Carnitine
L-carnitine supplementation may have negative cardiovascular effects, according to a recent study. Get the details in the Concerns and Cautions section of our Acetyl -L-Carnitine Review.
CL Answer
Are L-carnosine supplements helpful and safe?
Learn about the potential health benefits of L-carnosine, as well as possible safety concerns, drug interactions and cost.

CL Answer
Can any supplements improve or worsen symptoms of fibromyalgia?
Find out if any supplements may help improve fibromyalgia symptoms, learn which supplements do not seem beneficial, and find out if any supplements worsen symptoms.

CL Answer
Do any supplements reduce the side effects of chemotherapy? Should any be avoided?
Find out if there are any supplements that can help with the side effects of chemotherapy, such as nausea, vomiting, diarrhea, nerve damage and others. ConsumerLab.com's answer explains.

CL Answer
I take levothyroxine (Synthroid), a thyroid hormone to treat hypothyroidism. Are there supplements or foods I should avoid, or be taking, due to this drug?
Is taking certain supplements and hypothyroidism medications bad? Learn which supplements can interact with thyroid hormone medications like levothyroxine (Synthroid), thyroid hormone levels, and laboratory tests.

CL Answer
Do any supplements, foods or lifestyle modifications help with brain function, like memory and cognition?
Find out which supplements help improve memory, brain function and cognition, including fish oil, some B vitamins, cocoa, and curcumin. ConsumerLab's answer explains the evidence for supplements promoted to help with brain function and cognition.

Product Review
Huperzine A Supplements Review
Choose the Best Huperzine A Supplement. CL Tests Reveal the Best Huperzine A Supplements for Memory.

CL Answer
Do any supplements, foods, or oils help reduce muscle pain, muscle cramps, or nighttime leg cramps?
Find out which supplements, and topical products such as magnesium creams, can help reduce muscle pain, leg cramps, and nighttime leg cramps, and which may worsen muscle cramps. Also, learn about vitamin and mineral deficiencies and common medications that can cause muscle cramps and nocturnal leg cramps.

Product Review
Alpha-Lipoic Acid Supplements Review
Choose the Best Alpha-Lipoic Acid Supplement — See the Amounts of Active "R-Isomer" We Found

Product Review
Weight Loss Supplements Review (7-Keto DHEA, Forskolin and Stimulant Blend Supplements)
Choose the Best Weight Loss Supplement. Be Careful With Weight Loss Supplements — Few Pass Quality Testing and Safety Review.

CL Answer
Which supplements reduce hearing loss?
Can supplements such as alpha-lipoic acid, magnesium, N-acetyl-cysteine, folate or vitamins B-12, C and/or E help prevent or improve symptoms among people with hearing loss due to excessive noise or aging? Find out what the clinical evidence shows, and learn whether Advanced Hearing Formula, a supplement marketed for ear health, is likely to help.

CL Answer
What are "broad-spectrum micronutrient" supplements, and do they have greater health benefits than multivitamin/multimineral supplements?
Learn about "broad-spectrum micronutrients" and how they compare to multivitamin/multimineral supplements.

Recalls & Warnings
January 19, 2022
FDA Warns Seller of Carnitine and Alpha Lipoic Acid Supplements
On November 18, 2021, the FDA issued a warning letter to GeroNova Research Inc.
Product Review
Glutathione Supplements Review
Learn How Glutathione Products Differ, Which Failed, and Our Top Picks

News Release
November 18, 2008
Adulteration Suspected with Some "Memory" Supplements -- Few Ginkgo and Huperzine Supplements Pass ConsumerLab.com Tests; Quality High for Acetyl-L-Carnitine
WHITE PLAINS, NEW YORK — NOVEMBER 18, 2008 — Tests by ConsumerLab.com of Ginkgo biloba supplements show that few products meet quality standards.
CL Answer
Which supplements can help to lower blood pressure?
Supplements to lower blood pressure, including CoQ10, vitamin C, fish oil, and olive oil, are all explored to find out what works.

Recalls & Warnings
April 29, 2024
Longreen Reishi and Xlim Express Coffee Recalled Due to Undeclared Allergens
On April 18, 2024, BF Suma Pharmaceuticals, Inc.
News Release
October 28, 2008
Tests reveal quality problems with vitamin A supplements -- New ConsumerLab.com report focuses on vitamin A, including beta-carotene and cod liver oil
WHITE PLAINS, NEW YORK — OCTOBER 28, 2008 — ConsumerLab.com is cautioning that the amount vitamin A in some supplements may be much higher or lower than the amount stated on labels. Among ten supplements recently selected for testing, ConsumerLab.
Recalls & Warnings
September 10, 2013
CoQ10 and Carnitine Supplement Company Warned For Manufacturing Violations
On April 15, 2013, the FDA issued a warning letter to Irenda Corporation, following a facility inspection which found the company's products, including L-Carnitine, Acetyl L-Carnitine, and Co-Q 10 with L-Carnitine, to be adulterated because they were packed, or held under conditions that violate ...
Recalls & Warnings
September 10, 2012
Maker of Concussion Recovery Supplement Warned For Making Drug Claims
On August 28, 2012, the FDA issued a warning letter to Trinity Sports Group, Inc. after a review of the company's websites found statements about Neuro Impact Concussion Response Formula constituted drug claims not permitted on supplements.
News Release
October 02, 2008
ConsumerLab.com finds melatonin supplements range in strength but ingredient quality is high
WHITE PLAINS, NEW YORK — OCTOBER 2, 2008 — ConsumerLab.com announced test results today from its new Product Review of Melatonin Supplements. Melatonin supplements may help treat certain sleep disorders and disturbances, including jet lag.
News Release
September 17, 2008
ConsumerLab.com's tests of menopause supplements reveal wide range in strength and quality; mislabeling and contamination discovered -- Soy and red clover isoflavones, black cohosh, and progesterone products tested
WHITE PLAINS, NY — September 17, 2008 — Risks associated with traditional hormone therapy for symptoms of menopause have increased public interest in alternative treatments, particularly dietary supplements. But a report today of recent tests by ConsumerLab.
CL Answer
If I buy NAC as a loose powder in a large bag, as opposed to in tablet or capsule form, will it spoil? I've heard it can spoil or degrade into a harmful by-product.
Learn more about the different forms of N-Acetyl-Cysteine (NAC), including whether or not powder will spoil faster than tablets.

CL Answer
Is it true that NAC can help clear nasal passages?
Find out if N-Acetyl Cysteine (NAC) can help with post nasal drip & general sinus congestion and about supplements that may reduce cold symptoms.

CL Answer
What is the difference between cysteine and cystine?
Find out the difference between cysteine and cystine amino acids, including where each is found and their functions.

CL Answer
Is it safe to take arginine, or other supplements for sexual enhancement, while taking Viagra or Cialis?
When taking Cialis or Viagra, is it safe to take arginine or other sexual enhancement supplements?

News Release
August 12, 2008
ConsumerLab.com finds improvements in labeling of nutrition bars but potential pitfalls exist -- New report compares 20 bars, including those for protein, fiber, energy and whole food
WHITE PLAINS, NY — August 12, 2008 — Labeling on nutrition bars has become more accurate, according to a new report by ConsumerLab.com.
Clinical Update
1/21/2022
Seller of Carnitine and Alpha Lipoic Acid Warned by FDA
FDA Warns Seller of Carnitine and Alpha Lipoic Acid
Recalls & Warnings
September 05, 2014
Seller of "Nerve", "Cleanse" and Probiotic Supplements Warned for Drug Claims
On July 30, 2014, the FDA issued a warning letter to Plexus Worldwide, Inc., following a review of the company's website and product labels, which found statements made about Fast Relief, BioCleanse and ProBio5 to be drug claims.
Clinical Update
3/26/2016
NAC Reduces Compulsive Picking
A number of studies have shown that N-acetyl cysteine (NAC), a supplement with wide variety of uses, may also reduce compulsive behaviors. The most recent study showed significant improvement in adults with skin picking disorder. Details about this and other studies with NAC, and our ratings of NAC supplements, are found in the N-Acetyl Cysteine Supplements Review >>
Clinical Update
10/14/2022
How Much Zinc Causes Copper Deficiency?
High zinc intake can cause copper deficiency. A CL member asked us how much zinc (from zinc carnitine) would require them to supplement with copper. Find out in our Zinc Carnosine article and learn more in the Concerns and Cautions section of our Zinc Supplements Review, which also lists food sources of copper.
Recalls & Warnings
May 07, 2012
FDA Warns Doctor Promoting Own Supplements Online as Treatments
On April 18, 2012 the U.S. Food and Drug Administration (FDA) sent a Warning Letter to Jacob Teitelbaum, M.D. of Fatigued to Fantastic, LLC regarding the promotion that company's products on its website www.endfatigue.com.
News Release
January 25, 2006
Sexual enhancement supplements analyzed by Consumerlab.com
WESTCHESTER COUNTY, NEW YORK — JANUARY 25, 2006 — ConsumerLab.com announced today that it found only six out of eleven supplements used for sexual enhancement to contain key ingredients listed on their labels and meet other quality criteria.
News Release
January 03, 2006
Tests of memory enhancing supplements by ConsumerLab.com reveals lead in some ginkgo
WESTCHESTER COUNTY, NEW YORK — TUESDAY, JANUARY 3, 2006 — In its new test report on Memory Enhancement Supplements, ConsumerLab.com has revealed finding significant amounts of lead in certain products on the market.
Recalls & Warnings
March 13, 2013
Liquid Supplements Not Properly Manufactured Despite Certification
On February 22, 2013, the FDA issued a warning letter to Organics Corporation of America, dba Ambix Laboratories, following a facility inspection which found the company's dietary supplements Baby Plex Vitamin Drops, Carnitine Liquid, and Optimal Nutritional Liquid to be adulterated because they ...
Recalls & Warnings
September 07, 2002
FDA Sends Warning Letters to Seven Online Supplement Sellers For Therapeutic Claims
On August 27, 2002, the FDA posted seven "Cyber" letters recently issued from its Center for Food Safety and Applied Nutrition (CFSAN) to internet website operators promoting dietary supplement products that claim to diagnose, mitigate, treat, cure, or prevent a specific disease or class of ...
Recalls & Warnings
August 20, 2013
Weight Loss Supplement Formulas For Men and Women Recalled Due To Undeclared Drugs
On August 16, 2013, Herbal Give Care LLC issued a voluntary recall of all lots of weight loss dietary supplements Esbelder man, Esbelder fem and Esbelder siloutte because they were found to contain the undeclared drugs sibutramine, N-desmethylsibutramine, and N-di-desmethylsibutramine.
Recalls & Warnings
July 23, 2013
Weight Loss Supplements Containing Undeclared Drugs Recalled
On July 19, 2013, Herbal Give Care LLC issued a voluntary recall of all lots of weight loss supplements Esbelin siloutte te and Esbelin siloutte Herbal Blend with L-Carnitine because they were found to contain undeclared sibutramine, N-desmethylsibutramine, and N-di-desmethylsibutramine.
Recalls & Warnings
November 18, 2011
FDA Warns Maker of Milk Thistle and L-Carnitine Supplements of Serious Violations
The U.S. FDA posted a Warning Letter to CJ Labs (Miami, Florida) dated November 1, 2011 regarding serious violations of Good Manufacting Practices in the production of its Milk Thistle and L-Carnitine supplements.
Recalls & Warnings
March 06, 2015
FDA Warns Consumers Not to Buy or Use Weight Loss Supplement Containing Hidden Drug
On March 5, 2015, the FDA warned consumers not to buy or use weight loss supplement L-Carnitine Sob Strengthening Version Slimming Miracle Capsule because it was found to contain sibutramine.
Recalls & Warnings
August 29, 2013
Seller of CELLFOOD Supplements Warned For Manufacturing Violations and Drug Claims
On August 1, 2013, the FDA issued a warning letter to supplement retailer Lumina Health Products, Inc.
Recalls & Warnings
February 13, 2013
FDA Warns Maker of Weight Loss and Whey Protein Supplements For Manufacturing Violations and Misbranding
January 25, 2013, the FDA issued a warning letter to dietary supplement manufacturer SciLabs Nutraceuticals, following a facility inspection which found the company's dietary supplements and supplement ingredients, including N-Large 2, Flo-Gard AB, Nitrogen Glutamine capsules, Nutritech nutritional ...
Recalls & Warnings
January 21, 2017
Seller of "Cancer Kits," Alpha Lipoic Acid Supplements and More Warned for Drug Claims
On December 22, 2016, the FDA issued a warning letter to Northern Health Products, Inc. following a review of the company's websites, www.northernhealthproducts.com and www.petdca.
Recalls & Warnings
August 21, 2013
Seller of Vitamin, Tea and MSM Supplements Warned For Drug Claims
August 7, 2013, the FDA issued a warning letter to Vibrant Life Vitamins, following a review of the company's websites which found statements made about Taheebo Life Tea, Life Glow Plus, Super Life Glow, Life Glow Basic, Vibrant Life MSM, Herbal MSM, and Organic Germanium to be drug claims.