Slippery Elm: Gut and Throat Benefits, Dosage & Side Effects

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Slippery elm comes from the pale inner bark of Ulmus rubra, a tree native to the eastern and central United States and Canada.8 Stir the powdered bark into water and it thickens into a smooth, slippery gel.1 That gel coats a raw throat, a burning esophagus and an irritated gut lining, and it has made slippery elm a trusted American remedy for more than 200 years. It was listed in the very first U.S. Pharmacopeia, in 1820.9

Slippery elm is one of the lining-soothing herbs in two of my protocols,67 and I like it, along with marshmallow root, as one of the herbs that moisten the digestive tract.10 Human studies of throat teas and gut formulas made with it point the same way as that long tradition: quick comfort for a sore throat, and support for a gut that needs to calm down and heal.

Did you know?

• The FDA names elm bark as one of four demulcent ingredients, alongside gelatin, glycerin and pectin, allowed in over-the-counter products that soothe a sore mouth and throat.2

• In a 2025 survey in eastern Kentucky, slippery elm was among 14 medicinal plants local people still use.11

• In a 2022 lab study of tree barks used in Native American medicine, slippery elm extract strongly switched on KCNQ5, a potassium channel that helps smooth muscle relax.12

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What is slippery elm?

Only the inner bark is used. Physicians in the 1800s described it as sweetish and mild-smelling, "very mucilaginous, and slightly nutritious."1 That mucilage does the work. Chemists in the 1930s to 1950s worked out that it's built from long chains of sugars, including a methylated form of galactose,131415 and when the powder meets water, it becomes the slick gel the tree is named for.

A short history of slippery elm

Slippery elm bark was part of Native American botanical medicine,12 and American physicians took it up early. It was official in the U.S. Pharmacopeia from the first edition in 1820 until the 1930s, stayed in the National Formulary until 1960, and was readmitted to the official U.S. standards in 1995.9

American herbal physicians of the 1800s relied on it. The Physio-Medical Dispensatory (1869) used the inner bark for the bronchial tubes and lungs, the stomach and bowels, and dysentery, and as a poultice.1 King's American Dispensatory (1898) used it for irritated mucous membranes of the lungs, stomach, bowels, bladder and kidneys, for coughs, sore throats, diarrhea and dysentery, and in poultices for wounds, burns and ulcers.16 Modern researchers have tested it on much of that same list: the throat, the stomach and the bowels.345

What is slippery elm good for?

How slippery elm works in your body

The best-mapped route starts with the gel itself and ends with the bacteria in your gut.

Slippery elm benefits, ranked by evidence

Ranked by evidence, slippery elm does the most for a sore throat and an irritated upper gut, with encouraging results for IBS, the gut lining and the bacteria that live in your gut.

Is slippery elm good for a sore throat?

The trial ran in three primary care clinics in Minnesota and Wisconsin. Adults with acute pharyngitis, the medical name for a sore, inflamed throat, drank 5 to 8 ounces of the herbal tea or a placebo tea four to six times a day, and neither the people nor the researchers knew who got what. The tea combined licorice root, slippery elm bark and marshmallow root with wild cherry bark, fennel, cassia bark and sweet orange peel.321

Over the first 30 minutes after the first cup, throat pain dropped 43.8 points on a summed pain score with the herbal tea, against 16.5 points with placebo, and the tea's edge held across everyone who started the trial.3 It pulled ahead of placebo by the 5-minute check, and among the people who finished as planned, it stayed ahead at every check through 30 minutes; a second measure, total pain relief over the half hour, favored the tea only in that group.321

The FDA backs this use too. Its rules for over-the-counter mouth and throat products list elm bark as a demulcent "for temporary relief of minor discomfort and protection of irritated areas in sore mouth and sore throat." Elm-bark lozenges contain 10% to 15% bark and are dissolved slowly in the mouth, up to every 2 hours as needed.2

Lab research adds an interesting lead. An alcohol extract of slippery elm inner bark was among the five most effective of 14 plant extracts at killing Streptococcus pyogenes, the bacteria behind strep throat.22 That was a concentrated extract tested directly on bacteria, and a throat that might be strep needs testing; the warning signs are in who should be careful.

For a raw throat, sip slippery elm tea slowly or let a lozenge dissolve. My reflux protocol uses slippery elm for the same reason, as a traditional mucilage herb that coats the throat and esophagus.6 For more options, see natural sore throat remedies, homemade cough drops and laryngitis.

Does slippery elm help acid reflux and heartburn?

The formula combined curcumin from turmeric, aloe vera, slippery elm, guar gum, pectin, peppermint oil and glutamine. After a 4-week starting phase without it, participants took the formula for 12 weeks, 5 grams a day and then 10 grams a day, so each person served as their own comparison.4 Physical functioning, energy, mood and sleep improved by 60% to 80% as well. Almost half of those taking acid-blocking medicine for heartburn no longer needed it by the end of the study, and a third could eat trigger foods again, such as garlic, onion and beans or citrus, tomato and caffeine, without their symptoms returning.4 If you take an acid blocker, make any change with the doctor who prescribed it.

As I explain in my reflux protocol, most heartburn is acid in the wrong place. So the protocol starts with timing and gravity: an earlier dinner, no lying down after meals and a raised head of the bed.6 Slippery elm comes in during the second phase, Soothe, which runs from day 5 to day 20, at 1 to 2 teaspoons of powder in water between meals, alongside other lining soothers such as decolorized aloe vera juice and DGL licorice.6 For the food side, see the acid reflux diet and the GERD diet.

Can slippery elm help IBS, constipation and diarrhea?

The constipation formula, given to 10 adults, was mostly slippery elm: 14 grams of the bark a day in a 27-gram daily mix with lactulose, oat bran and licorice root. Along with 20% more bowel movements, people had better-formed stools and less straining, abdominal pain and bloating, and their overall IBS symptom scores fell.5

The second formula, given to 21 adults with diarrhea-type or alternating IBS, combined bilberry fruit, slippery elm bark, agrimony and cinnamon. It eased straining, abdominal pain, bloating and gas and improved overall IBS symptoms, though it didn't settle bowel habits; stool frequency rose slightly. In both groups, people knew which formula they were taking and there was no comparison group, and both formulas were well tolerated.5

Look at the root cause too. In my SIBO protocol, I point out that many people who are told they have IBS have SIBO, an overgrowth of bacteria in the small intestine that a breath test can show.23 If bloating and gas lead your symptoms, the SIBO protocol is worth a look, and the IBS diet, natural constipation remedies and how to stop diarrhea cover the food side.

Does slippery elm help leaky gut?

Slippery elm helps a leaky gut heal as one of the herbs that soothe and coat the lining, and in a 16-week before-and-after study, a seven-part formula that includes it improved gut permeability, with 66% to 100% of participants ending with a normal result, depending on their stool type.4 The researchers used the lactulose-mannitol test, which compares how much of two sugars pass through the gut wall into the urine. Of the 42 participants tested before and after 12 weeks on the formula, all of those with normal stools (100%) had a normal ratio, up from 56% at the start, as did 90% of those with hard stools (up from 57%) and 66% of those with soft stools (up from 33%), and Lactobacillus, Clostridium and Faecalibacterium prausnitzii rose in their gut bacteria.4

A whole-diet program that included slippery elm also improved gut permeability. In five case reports, adults with chronic plaque psoriasis followed a diet of fresh fruits and vegetables, small amounts of fish and fowl, fiber supplements and olive oil, with saffron tea and slippery elm bark water every day, for six months. Their permeability scores improved from 0.066 to 0.026, their Psoriasis Area and Severity Index scores fell from an average of 18.2 to 8.7, and a second severity scale fell from 14.6 to 5.4.19

That's where slippery elm sits in my approach to leaky gut. My Healing Leaky Gut protocol lists slippery elm with marshmallow root, 1 to 3 grams a day, as mucilaginous herbs that soothe and coat the lining,7 and my leaky gut guide adds slippery elm, marshmallow root or DGL in the Repair phase for extra lining support.24 I typically encourage people to take these herbs as teas. One simple routine is a daily tea of turmeric, ginger and slippery elm (or licorice), drunk twice a day to help heal your gut lining.25

Soothing herbs work best inside the whole plan: removing what irritates your gut, reinoculating with probiotics, and repairing with nutrients such as L-glutamine and collagen.7 See leaky gut supplements and the leaky gut diet for the rest of the plan.

How to use slippery elm

Throat relief in the tea trial began within 5 minutes,3 while the gut results came over weeks; in my leaky gut protocol, the most measurable changes in symptoms come by days 21 to 30.7

What's the difference between slippery elm, marshmallow root and licorice?

Slippery elm, marshmallow root and licorice are the classic soothing trio, and they often work together; the throat tea in the trial above used all three.3

If you can find only one, the reflux protocol treats slippery elm and marshmallow root as one choice, either one between meals.6

How to buy slippery elm

Look for these on the label and from the seller:

• Inner bark of Ulmus rubra (or its older name, Ulmus fulva), the part and species in the U.S. Pharmacopeia9

• Cultivated or responsibly harvested bark. Dutch elm disease has left very few mature slippery elm trees in nature, so United Plant Savers lists slippery elm as at-risk and asks buyers to avoid wild-harvested bark unless it came from trees that fell naturally.26

• The form that fits the job: Choose fine powder for drinks, tea bags for a daily tea, and lozenges with 10% to 15% elm bark for your throat.2

• Plain bark with nothing added, so you control the sweetness; if you want it sweeter, stir in a little raw honey

Slippery elm side effects & who should be careful

Its safety record is strong. LiverTox, the U.S. government's database on liver injury from drugs and supplements, describes slippery elm as generally recognized as safe, with no evidence that it raises liver enzymes or causes liver injury,8 and the FDA allows elm bark in over-the-counter throat lozenges.2 A search of the medical literature turns up no report of kidney damage from slippery elm taken by mouth. In the studies on this page, both IBS formulas were well tolerated,5 and 2 of the 50 people who started the seven-part gut formula stopped in the first month because of severe constipation or bloating.4 In one published case, the authors suspected a product rich in slippery elm as the trigger of a woman's eosinophilic colitis, a rare allergic-type inflammation of the colon.27

The bottom line

Slippery elm: frequently asked questions

References

1. Cook WH. Ulmus fulva: slippery elm. In: The Physio-Medical Dispensatory. Cincinnati; 1869.
2. U.S. Food and Drug Administration. Final Administrative Order OTC000028: Over-the-Counter Monograph M022, Oral Healthcare Drug Products for Over-the-Counter Human Use (§ M022.18 Demulcents; § M022.58 Labeling of demulcent drug products). Posted October 14, 2022.
3. Brinckmann J, Sigwart H, van Houten Taylor L. Safety and efficacy of a traditional herbal medicine (Throat Coat) in symptomatic temporary relief of pain in patients with acute pharyngitis: a multicenter, prospective, randomized, double-blinded, placebo-controlled study. J Altern Complement Med. 2003;9(2):285-98. doi:10.1089/10755530360623400
4. Ried K, Travica N, Dorairaj R, et al. Herbal formula improves upper and lower gastrointestinal symptoms and gut health in Australian adults with digestive disorders. Nutr Res. 2020;76:37-51. doi:10.1016/j.nutres.2020.02.008
5. Hawrelak JA, Myers SP. Effects of two natural medicine formulations on irritable bowel syndrome symptoms: a pilot study. J Altern Complement Med. 2010;16(10):1065-71. doi:10.1089/acm.2009.0090
6. Axe J. Acid Reflux & GERD Protocol: The 30-Day Healing Protocol. DrAxe.com; 2026: p. 17 (Phase 2, Soothe) and p. 20 (Top 8 soothing remedies).
7. Axe J. Healing Leaky Gut Protocol. DrAxe.com; 2025 (supplement table, Recommended tier; phase Supplement focus).
8. LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. Slippery Elm. Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases; updated January 5, 2024.
9. Brinckmann J, Marles R, Schiff P, et al. Quality Standards for Botanicals: The Legacy of USP's 200 Years of Contributions (full paper). HerbalGram. 2020;(126).
10. Axe J. Top 5 Ways to Heal Leaky Gut NATURALLY. The Dr. Axe Show (episode). 2024.
11. Veldhi P, Crager C, Ghayur A, et al. A Review and Survey of Local Eastern Kentucky Medicinal Plants and Their Pharmacological Benefits. Plants (Basel). 2025;14(20):3182. doi:10.3390/plants14203182
12. Manville RW, Redford KE, van der Horst J, et al. KCNQ5 activation by tannins mediates vasorelaxant effects of barks used in Native American botanical medicine. FASEB J. 2022;36(9):e22457. doi:10.1096/fj.202200724R
13. Anderson E. The mucilage from slippery elm bark. J Biol Chem. 1934;104(1):163-170. doi:10.1016/s0021-9258(18)75803-1
14. Gill RE, Hirst EL, Jones JKN. Constitution of the mucilage from the bark of Ulmus fulva (slippery elm mucilage); the sugars formed in the hydrolysis of the methylated mucilage. J Chem Soc. 1946:1025-9. doi:10.1039/jr9460001025
15. Hough L, Jones JKN, Hirst EL. Chemical constitution of slippery elm mucilage; isolation of 3-methyl d-galactose from the hydrolysis products. Nature. 1950;165(4184):34. doi:10.1038/165034a0
16. Felter HW, Lloyd JU. Ulmus (U.S.P.): elm. In: King's American Dispensatory. 18th ed. Cincinnati: Ohio Valley Co.; 1898.
17. Peterson CT, Sharma V, Uchitel S, et al. Prebiotic Potential of Herbal Medicines Used in Digestive Health and Disease. J Altern Complement Med. 2018;24(7):656-665. doi:10.1089/acm.2017.0422
18. Langmead L, Dawson C, Hawkins C, et al. Antioxidant effects of herbal therapies used by patients with inflammatory bowel disease: an in vitro study. Aliment Pharmacol Ther. 2002;16(2):197-205. doi:10.1046/j.1365-2036.2002.01157.x
19. Brown AC, Hairfield M, Richards DG, et al. Medical nutrition therapy as a potential complementary treatment for psoriasis--five case reports. Altern Med Rev. 2004;9(3):297-307.
20. Choi HR, Choi JS, Han YN, et al. Peroxynitrite scavenging activity of herb extracts. Phytother Res. 2002;16(4):364-7. doi:10.1002/ptr.904
21. Is herbal tea effective for pain of acute pharyngitis? (POEM summary of Brinckmann et al., 2003). Am Fam Physician. 2003;68(9):1840.
22. Wijesundara NM, Rupasinghe HPV. Bactericidal and Anti-Biofilm Activity of Ethanol Extracts Derived from Selected Medicinal Plants against Streptococcus pyogenes. Molecules. 2019;24(6):1165. doi:10.3390/molecules24061165
23. Axe J. SIBO Protocol. DrAxe.com; 2026: p. 4 (The silent epidemic).
24. Axe J. Leaky Gut: Symptoms, Root Causes, Testing & the 6R Healing Protocol. DrAxe.com; published September 10, 2026 (Repair phase).
25. Axe J. Complete Guide to Healing Leaky Gut Naturally | Dr. Josh Axe. The Dr. Axe Show (episode). 2026.
26. United Plant Savers. Slippery Elm (Ulmus rubra). Species At-Risk profile.
27. Amado C, Silva Leal M, Neto P, et al. Subserous Type of Eosinophilic Colitis: A Rare Disease. Eur J Case Rep Intern Med. 2021;8(7):002671. doi:10.12890/2021_002671
28. Wellcome Collection. Slippery Elm Bark. Sold as an abortifacient. (catalogue record)
29. González Canga A, Fernández Martínez N, Sahagún Prieto AM, et al. Dietary fiber and its interaction with drugs. Nutr Hosp. 2010;25(4):535-9.
30. DailyMed. ONELAX FIBER THERAPY ORIGINAL COARSE: psyllium husk powder, Drug Facts label (bulk-forming fiber and other medicines). National Library of Medicine.

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