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What Are Ear Seeds And How Do They Work?

Published on May 15, 2023


By Kristen Boye BS, Natural Health

Kristen Boye

Kristen Boye is a natural health expert, writer, copywriter, and editor. Kristen was raised on an organic farm in British Columbia which inspired her life’s work. She holds a Bachelor’s Degree in Natural Health, is a Certified Natural Foods Chef, co-owner of a medicinal herb farm, and is a natural foods and children’s health advocate. Kristen lives with her husband and two children on their medicinal herb farm in Western North Carolina.

https://www.holisticwritingconcepts.com

Social media influencers have been raving about the benefits of using ear seeds for back pain, relaxation, sleep, weight loss, and more.

But what exactly are ear seeds, how do they work, and are their claims legitimate?

Ear seeding is a form of auricular (ear) acupuncture, a type of acupressure that stimulates specific acupuncture points on the ear without needles.

Proponents claim it can relieve pain and support various aspects of physical, mental, and emotional well-being.

There is also research that looks into many of its traditional uses.

Read on for a crash course on the history, traditional use, science, benefits, side effects, and potential contraindications of ear seeding.

What Are Ear Seeds?

Ear seeding may seem like a new trend, but it is based on principles of Traditional Chinese Medicine (TCM).

Ear seeds are used within the scope of auricular acupuncture, a type of acupuncture (in which needles are used) or acupressure (where pressure is used instead of needles) focused on the ears.

In Traditional Chinese medicine, the ears are believed to reflect the condition of internal organs. 

Therefore, auricular acupuncture uses specific acupuncture points on the ears to stimulate the flow of “Qi” or energ,y to specific organs and systems.

Here’s a little history of this ancient technique dating back thousands of years.

According to an article published in Medical Acupuncture, the first records describing the relationship between the ears and other organs were written in a Chinese text between 770 and 220 AD. REF#1666

The first auricular map (a map of the acupuncture points on the ears) was published in 1888.

Paul Nogier, MD, is considered the “Father of Auricular Medicine” and is credited with the discovery of ear somatotopy, a representation of the whole person on the ear in the shape of an inverted fetus.

Dr. Paul Nogier's ear map was first published in 1957, the basis for the official World Health Organization ear map.

What exactly is an ear seed?

Ear seeds are small stickers (usually latex and a little smaller than the size of a pinkie fingernail) that traditionally contain a ripe seed from the Vaccaria plant in the middle. 

The “seed” portion may also be made of synthetic materials, such as ion pellets, magnets, stainless steel, etc., designed to mimic a seed.

These seeds or pellets are applied to specific acupuncture points on the ears, either by a trained acupuncturist or at home. The sticker part is designed to keep the seed affixed to the ear on the chosen pressure point.

The seed allows the person to gently stimulate the acupuncture point using gentle pressure without using needles.

Earseeding is typically done by an acupuncturist or Doctor of Oriental Medicine trained to find the correct acupuncture points.

However, home ear seeding kits with tutorials are also available.

How Do Acupressure Ear Seeds Work?

As discussed previously, according to Traditional Chinese Medicine, acupressure ear seeds work by stimulating specific ear acupuncture points that correspond with various organs and systems.

An ear seed adequately placed on the correct acupuncture point acts like an acupuncture needle without needing a needle. 

The person with the ear seed on their ear applies gentle pressure a few times daily to stimulate the point.

How does stimulating a point on your ear potentially relieve symptoms or improve health?

Since acupuncture is primarily an energetic healing method—designed to stimulate and balance the flow of Qi (energy) throughout the body—the mechanism behind its actions remains somewhat mysterious.

However, research shows acupuncture and acupressure can stimulate the release of endorphins, and other pleasurable impulses, that can help overcome pain or discomfort. REF#1667

New research from Korea on the Primo Vascular System has validated the existence of the 12 meridian systems on which Traditional Chinese Medicine is based.

Here’s a quote from the 2013 study entitled: “The Primo Vascular System as a new anatomical system.”

“The PVS (Primo Vascular System) is a previously unknown system that integrates the features of the cardiovascular, nervous, immune, and hormonal features. It also provides a physical substrate for the acupuncture points and meridians.”

These meridians run vertically throughout the body. They are considered the energy pathways that connect the Qi to the different acupuncture points that correspond to other organs and systems.

When an acupuncturist inserts needles or applies ear seeds, they work on the meridian systems via the acupuncture points.

What Are Ear Seeds Used For?

Ear Seeds have been used for various health concerns by Traditional Chinese Medicine practitioners and individuals. 

Some of these concerns include:

  • Anxiety
  • Depression
  • Food cravings
  • Infertility
  • Insomnia
  • Headaches/Migraines
  • Pain
  • Stress
  • Substance abuse
  • Weight loss

There is plenty of historical and anecdotal evidence behind the benefits of ear seeds, but what does the science say?

Let’s explore that next.

5 Proven Benefits of Trying Ear Seeds

Traditional Chinese Medicine, including Chinese herbs and acupuncture, is one of the most-studied alternative forms of medicine in the world.

This includes auricular acupuncture and ear seeding, which have demonstrated potential benefits for the following ailments.

1: Ear Seeds May Help With Various Types of Pain, Including Back Pain & Menstrual Cramps

If you’ve ever lived with pain, you know how difficult it can be to manage and cope. 

Especially if you’re trying to avoid the potential side effects and addictive nature of prescription or over-the-counter painkillers.

This is why many people try ear seeding and traditional acupuncture; but does it work?

Researchers have become interested in the possible merits of acupuncture and acupressure techniques, like ear seeding, for pain due to the opioid epidemic.

What they’ve uncovered is encouraging.

Research published in Johns Hopkins Nursing entitled: “Effects of Auricular Point Acupressure on Pain Relief: A Systematic Review” REF#1667 found auricular point acupressure (APA)/ear seeding effective used alone for low back pain and menstrual cramps.

The review also found ear seeding was effective for most acute pain when combined with various other interventions. 

Another review entitled: “Auricular Acupuncture For Chronic Back Pain In Adults: A Systematic Review And Meta Analysis” REF#1668 analyzed the results of 427 studies and found ear seeding was effective 80% of the time for reducing chronic back pain in adults.

These results are consistent with many studies validating acupuncture’s efficacy in treating various types of pain. REF#1669

The nice thing about ear seeding is you may reap the potential benefits of acupuncture for pain without weekly acupuncture appointments.

This may not be the case for every person. Still, based on the evidence, it may be worth a try.

2: Ear Seeds May Help You Sleep

Sleep deprivation has become a serious problem in America, with 1 in 3 Americans not getting enough sleep (between 7 and 9 hours per night). REF#1670

The problem with this trend isn’t just about drowsy adults and children. 

Sleep deprivation has been linked to various chronic conditions, including: REF#1671 REF#1672

  • Anxiety
  • Cognitive decline
  • Depression
  • Heart Disease
  • Hormonal imbalances
  • Obesity
  • Metabolic syndrome
  • Pain
  • Reduced immunity 
  • And others

If you’ve dealt with persistent sleep issues, you know it’s not always a matter of going to bed earlier or cutting back on caffeine.

For many people, sleep issues may be rooted in various physical, mental, and/or emotional factors.

Plus, the stress of not sleeping may create a vicious cycle of worry that exacerbates the problem.

If this scenario sounds familiar and you’re looking for a natural solution, you may find some relief in ear seeding.

A clinical trial published in Alternative Therapies In Health And Medicine found auricular acupuncture reduced sleep disorder symptoms. It provided some relief for anxiety and Temporomandibular disorders (TMD or jaw pain). REF#1673

In addition, since ear seeding has been shown effective for reducing other types of pain (as previously discussed), it could be effective for anyone losing sleep due to pain-related issues.

Your acupuncturist can instruct you on the best times of day to massage your ear seeds for optimal sleep.

There are also online tutorials with general instructions on using ear seeds for sleep.

#3: Ear Seeds May Help With Weight Loss

You’ve probably heard influencers raving about how ear seeds helped them lose weight by controlling food cravings.

There is some evidence to validate these claims.

A small pilot study published in BMJ Open Gastroenterology aimed to identify the mechanism behind auricular acupuncture’s (not acupressure) traditional use for reducing appetite and aiding weight loss. REF#1674

Researchers recruited ten adults (9 women and one man) and gave half auricular acupuncture on the correct points and half placebo.

They found a statistically significant difference in the percentage change in body weight and active ghrelin levels in each participant in auricular acupuncture groups. 

Ghrelin is known as the “hunger hormone” because it controls appetite and cravings. REF#1675

This research suggests that auricular acupuncture can positively affect Ghrelin levels, resulting in weight loss.

The jury’s out on whether auricular acupressure/ear seeding could have the same effect. However, it is possible since the same acupuncture points are used in both methods. 

#4: Ear Seeds May Help With Stress & Anxiety

Anxiety is a part of life. No matter who you are or what your background is, everyone experiences anxiety.

However, that doesn’t mean it’s not disruptive, especially during times of stress or for those who suffer from more severe anxiety.

Fortunately, there are many ways to cope with occasional anxiety.

This may include meditation, counseling, regular exercise, spending time with loved ones, using adaptogenic herbs like Ashwagandha*, regular self-care practices, acupuncture, and/or ear seeding.

A study by two Yale researchers published in Anesthesia and Analgesia entitled: “Auricular acupuncture: a potential treatment for anxiety” found auricular acupuncture could decrease anxiety levels in otherwise healthy subjects experiencing intense levels of daily stress and anxiety. REF#1676

Additional research has shown a combination of body and auricular acupuncture can reduce symptoms of minor depression, chronic anxiety disorders, and general anxiety disorders. REF#1677

Once again, these studies point to the benefits of auricular acupuncture versus acupressure/ear seeding for anxiety.

However, many practitioners and individuals have reported success using ear seeding in the same manner for occasional anxiety.

How To Place Ear Seeds

Placing ear seeds correctly takes practice and precision. You could miss the benefits if you miss the point by even a millimeter.

This is why experts, including Andreas Wirz-Ridolfi, MD, a leading authority on auricular acupuncture, stress that precision in locating the correct point is critical to achieving results.

Acupuncturists and Doctors of Oriental Medicine attend accredited acupuncture schools for at least four years (in addition to undergrad studies) to learn how to locate acupuncture points properly.

If you’d like to attempt placing your own ear seeds, you can buy a DIY ear seeding kit and follow tutorials or have a licensed acupuncturist or Doctor of Oriental Medicine show you how and where to place the ear seed.

It is your choice, but you may get better results having ear seeds professionally placed.

How To Remove Ear Seeds

Ear seeds will usually lose their stickiness after 3-5 days.

To remove, pull gently, like you would with a bandaid.

Check with your acupuncturist or Doctor of Oriental Medicine about re-application. Or, if you’re DIYing your ear seeds, re-apply per manufacturer’s recommendations.

Possible Side Effects & Contraindications of Ear Seeds

Ears seeds are generally safe to use, but there are some things to be aware of.

Side effects may include: REF#1678

    • Accidental labor: Certain points on the ear can stimulate contractions during pregnancy. Therefore, pregnant women should avoid ear seeding unless done by a professional acupuncturist.
    • Allergic reaction: This is usually for those with a latex allergy. Latex-free ear seeds are available.
    • Dizziness or nausea: Applying the ear seed to the wrong point and/or stimulating it can result in feelings of faintness, dizziness, or nausea
  • Loss of ear seed in the ear canal: Although ear seeds affixed with adhesive, they can come off. If this happens, medical attention may be required to remove them safely. This is another reason to consider having them placed professionally.
  • Skin tenderness or irritation: This can result from rubbing ear seeds too hard or too often or leaving them on too long. Generally, ear seeds are left on for 2-3 days, then taken off for 2-3 days. Your practitioner can advise you. Some practitioners believe soreness indicates blocked Qi on that point and may advise you to stay the course.

Finally, as you’ve just learned, acupuncture and acupressure can potentially change your health.

Therefore, always check with your doctor or healthcare practitioner if you have a pre-existing condition, are taking medication, or have health concerns.

Herbs to Accompany To Ear Seeds

Various herbal supplements may offer many of the same benefits as ear seeds without placement issues. 

Herbs can also work in conjunction with ear seeds to provide the user with potentially greater benefits.

Here are some complementary herbs to consider:

Herbs for Occasional Pain or Menstrual Cramps

  • Ginger has may have benefits for menstrual cramping, joint and muscle health, inflammatory response, and headaches. REF#1683 REF#1684 REF#1685
  • Vitex may helpto reduce several symptoms of PMS, including: REF#1686 REF#1687 REF#1688
      • Mood swings
      • Occasional Anxiety associated with PMS
      • Cravings
      • Hyperhydration (bloating)
      • Menstrual cramps
  • Crampbark has demonstrated some benefits for uterine spasms/cramping, but more research is needed. REF#1684

Learn more in: 7 Best Herbs For Everyday Pain To Support Additional Pain Relief And Restore Balance.

Herbs To Support Sleep And Stress Response

The most popular herbs for sleep and stress/ocassional anxiety support typically fall under two categories:

  • Nervines: Which support normal nervous system function
  • Adaptogens: Which support a healthy stress response

Some examples of these herbs include:

  • Ashwagandha: An Ayurvedic adaptogen that has been shown to support various aspects of healthy sleep, stress response, and for occasional anxiety.REF#1685 REF#1686 REF#1687
  • Valerian: A nervine with sleep- and relaxation-promoting properties. REF#1689

Learn more in: 

Herbs To Support A Healthy Weight And Appetite

Herbs alone will not help you lose weight. 

However, the following herbs may have benefits when used in conjunction with a healthy lifestyle.

  • Ashwagandha has been shown to support thyroid REF#1690 sleep, REF#1691 REF#1692 and adrenal health, REF#1693 all of which can be tied to issues with weight.
  • Panax Ginseng may helpsupport normal appetite and blood sugar. REF#1694 REF#1695 REF#1696

Learn more in: Do Weight-Loss Supplements Work? Here’s What You Need To Know

Ready To Test Out Ear Seeds?

As you’ve learned, there are many potential benefits to trying ear seeds with minimal risk.

If you’re interested in ear seeding, seek a licensed acupuncturist or Doctor of Oriental Medicine.

These professionals can perform Traditional Chinese Medicine diagnostics and help you determine the best auricular acupressure points to meet your needs. 

They can also apply the ear seeds to ensure precise placement and instruct you on the best way to use them and how often to replace them.

If you’re determined to DIY your ear seeds, look for kits from reputable companies with detailed tutorials. 

Be sure to read the reviews and do your due diligence! 

Just because you’re not ingesting the ear seeds doesn’t mean it’s not critical to research the company, the quality of its products, and its manufacturing practices.

The wrong adhesive, for example, can be toxic, and if you’re allergic to latex, you’ll need to find a latex-free option.

Finally, follow expert-led tutorials from licensed acupuncturists or doctors vs. relying on instructions from influencers or celebrities. 

Precision counts with ear seeding, so it’s essential to get it right.

Are you interested in more natural solutions for better health?


Check our Seeds Of Knowledge Blog for in-depth, science-based information on a variety of health and wellness topics.

REFERENCES:

  • 1. Johns Hopkins Medicine, "9 Benefits of Yoga", . https://www.hopkinsmedicine.org/health/wellness-and-prevention/9-benefits-of-yoga
  • 2. , "1 in 3 adults don’t get enough sleep", Centers for Disease Control and Prevention. https://www.cdc.gov/media/releases/2016/p0215-enough-sleep.html
  • 3. Centers for Disease Control and Prevention, "10 Surprising Things That Can Spike Your Blood Sugar", CDC > Diabetes Home > Resources and Publications > Features. https://www.cdc.gov/diabetes/library/spotlights/blood-sugar.html
  • 4. Eric Suni & Alex Dimitriu, Psychiatrist MD, "Sleep Deprivation", Sleep Foundation > Sleep Deprivation. https://www.sleepfoundation.org/sleep-deprivation
  • 5. Andréa Cândido Dos Reis, Thaisa Theodoro de Oliveira, Carla Larissa Vidal, Maria Cristina Borsatto, Mariana Lima da Costa Valente, "Effect of Auricular Acupuncture on the Reduction of Symptoms Related to Sleep Disorders, Anxiety and Temporomandibular Disorder (TMD)", Clinical Trial Altern Ther Health Med . 2021 Mar;27(2):22-26.. https://pubmed.ncbi.nlm.nih.gov/33711819/
  • 6. Hisayuki Ito 1, Osamu Yamada 2, Yuji Kira 3, Takeshi Tanaka 4, Rumiko Matsuoka 5, "The effects of auricular acupuncture on weight reduction and feeding-related cytokines: a pilot study", BMJ Open Gastroenterol . 2015 Feb 9;2(1):e000013. doi: 10.1136/bmjgast-2014-000013. eCollection 2015.. https://pubmed.ncbi.nlm.nih.gov/26462269/
  • 7. Melissa Glim, "Hunger Hormone Feeds Alcohol Cravings", Intramural Research Program (IRP). https://irp.nih.gov/about-us/what-is-the-irp
  • 8. S M Wang 1, Z N Kain, "Auricular acupuncture: a potential treatment for anxiety", Clinical Trial Anesth Analg . 2001 Feb;92(2):548-53. doi: 10.1097/00000539-200102000-00049.. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8138407
  • 9. Editorial staff members, "Auricular Acupuncture Effective in Treating Anxiety Technique Could Reduce Pain and Stress in Postsurgical Patients", Acupuncture Today. https://acupuncturetoday.com/article/27830-auricular-acupuncture-effective-in-treating-anxiety
  • 10. Cleveland Clinic, "Thinking About Using Ear Seeds? What You Should Know", December 20, 2021 / Wellness. https://health.clevelandclinic.org/ear-seeds/
  • 11. Russo AF., "Calcitonin gene-related peptide (CGRP): a new target for migraine.", Annu Rev Pharmacol Toxicol. 2015;55:533-52. doi: 10.1146/annurev-pharmtox-010814-124701. Epub 2014 Oct 8. PMID: 25340934; PMCID: PMC4392770.. https://https://pubmed.ncbi.nlm.nih.gov/25340934/.ncbi.nlm.nih.gov/pmc/articles/PMC8138407
  • 12. Burbach JP., "What are neuropeptides?", Methods Mol Biol. 2011;789:1-36. doi: 10.1007/978-1-61779-310-3_1. PMID: 21922398.. https://pubmed.ncbi.nlm.nih.gov/21922398/
  • 13. Shep D, Khanwelkar C, Gade P, Karad S., "Safety and efficacy of curcumin versus diclofenac in knee osteoarthritis: a randomized open-label parallel-arm study.", Trials. 2019 Apr 11;20(1):214. doi: 10.1186/s13063-019-3327-2. PMID: 30975196; PMCID: PMC6460672.. ncbi.nlm.nih.gov/pmc/articles/PMC6460672/
  • 14. Zhiqiang Wang et al.,, "Effectiveness of Curcuma longa Extract for the Treatment of Symptoms and Effusion–Synovitis of Knee Osteoarthritis", ACP Journals,1 December 2020. https://www.acpjournals.org/doi/10.7326/M20-0990
  • 15. Rahnama P, Montazeri A, Huseini HF, Kianbakht S, Naseri M., "Effect of Zingiber officinale R. rhizomes (ginger) on pain relief in primary dysmenorrhea: a placebo randomized trial.", BMC Complement Altern Med. 2012 Jul 10;12:92. doi: 10.1186/1472-6882-12-92. PMID: 22781186; PMCID: PMC3518208.. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3518208/
  • 16. Maghbooli M, Golipour F, Moghimi Esfandabadi A, Yousefi M., "Comparison between the efficacy of ginger and sumatriptan in the ablative treatment of the common migraine.", Phytother Res. 2014 Mar;28(3):412-5. doi: 10.1002/ptr.4996. Epub 2013 May 9. PMID: 23657930.. https://pubmed.ncbi.nlm.nih.gov/23657930/
  • 17. Black CD, Herring MP, Hurley DJ, O'Connor PJ., "Ginger (Zingiber officinale) reduces muscle pain caused by eccentric exercise.", J Pain. 2010 Sep;11(9):894-903. doi: 10.1016/j.jpain.2009.12.013. Epub 2010 Apr 24. PMID: 20418184.. https://pubmed.ncbi.nlm.nih.gov/20418184/
  • 18. Anita Rani and Anupam Sharma, "The genus Vitex: A review", Pharmacogn Rev. 2013 Jul;7(14):188-98. doi: 10.4103/0973-7847.120522. PMID: 24347927; PMCID: PMC3841997.. https://wwhttps://www.ncbi.nlm.nih.gov/pmc/articles/PMC3841997/w.ncbi.nlm.nih.gov/pmc/articles/PMC3841997/
  • 19. Loch EG, Selle H, Boblitz N., "Treatment of premenstrual syndrome with a phytopharmaceutical formulation containing Vitex agnus castus.", J Womens Health Gend Based Med. 2000 Apr;9(3):315-20. doi: 10.1089/152460900318515. PMID: 10787228.. https://pubmed.ncbi.nlm.nih.gov/10787228/
  • 20. Schellenberg R., "Treatment for the premenstrual syndrome with agnus castus fruit extract: prospective, randomised, placebo controlled study.", BMJ. 2001 Jan 20;322(7279):134-7. doi: 10.1136/bmj.322.7279.134. PMID: 11159568; PMCID: PMC26589.. https://pubmed.ncbi.nlm.nih.gov/11159568/
  • 21. Bent S, Padula A, Moore D, Patterson M, Mehling W., "Valerian for sleep: a systematic review and meta-analysis.", Am J Med. 2006 Dec;119(12):1005-12. doi: 10.1016/j.amjmed.2006.02.026. PMID: 17145239; PMCID: PMC4394901.. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4394901/
  • 22. Sharma AK, Basu I, Singh S., "Efficacy and Safety of Ashwagandha Root Extract in Subclinical Hypothyroid Patients: A Double-Blind, Randomized Placebo-Controlled Trial.", J Altern Complement Med. 2018 Mar;24(3):243-248. doi: 10.1089/acm.2017.0183. Epub 2017 Aug 22. PMID: 28829155.. https://pubmed.ncbi.nlm.nih.gov/28829155/
  • 23. Langade D, Thakare V, Kanchi S, Kelgane S., "Clinical evaluation of the pharmacological impact of ashwagandha root extract on sleep in healthy volunteers and insomnia patients: A double-blind, randomized, parallel-group, placebo-controlled study.", J Ethnopharmacol. 2021 Jan 10;264:113276. doi: 10.1016/j.jep.2020.113276. Epub 2020 Aug 17. PMID: 32818573.. https://pubmed.ncbi.nlm.nih.gov/32818573/
  • 24. Abhijit Deshpande et al.,, "A randomized, double blind, placebo controlled study to evaluate the effects of ashwagandha (Withania somnifera) extract on sleep quality in healthy adults", Sleep Medicine Volume 72, August 2020, Pages 28-36. https://www.sciencedirect.com/science/article/abs/pii/S1389945720301246
  • 25. Chandrasekhar K, Kapoor J, Anishetty S., "A prospective, randomized double-blind, placebo-controlled study of safety and efficacy of a high-concentration full-spectrum extract of ashwagandha root in reducing stress and anxiety in adults.", Indian J Psychol Med. 2012 Jul;34(3):255-62. doi: 10.4103/0253-7176.106022. PMID: 23439798; PMCID: PMC3573577.. https://pubmed.ncbi.nlm.nih.gov/23439798/
  • 26. Phung HM, Jang D, Trinh TA, Lee D, Nguyen QN, Kim CE, Kang KS., "Regulation of appetite-related neuropeptides by Panax ginseng: A novel approach for obesity treatment.", J Ginseng Res. 2022 Jul;46(4):609-619. doi: 10.1016/j.jgr.2022.03.007. Epub 2022 Apr 4. PMID: 35818423; PMCID: PMC9270656.. https://pubmed.ncbi.nlm.nih.gov/35818423/
  • 27. Shishtar E, Sievenpiper JL, Djedovic V, Cozma AI, Ha V, Jayalath VH, Jenkins DJ, Meija SB, de Souza RJ, Jovanovski E, Vuksan V., "The effect of ginseng (the genus panax) on glycemic control: a systematic review and meta-analysis of randomized controlled clinical trials.", PLoS One. 2014 Sep 29;9(9):e107391. doi: 10.1371/journal.pone.0107391. PMID: 25265315; PMCID: PMC4180277.. https://pubmed.ncbi.nlm.nih.gov/25265315/
  • 28. Shergis JL, Zhang AL, Zhou W, Xue CC., "Panax ginseng in randomised controlled trials: a systematic review.", Phytother Res. 2013 Jul;27(7):949-65. doi: 10.1002/ptr.4832. Epub 2012 Sep 12. PMID: 22969004.. https://pubmed.ncbi.nlm.nih.gov/22969004/