What Is Slippery Elm?

An Herbal Treatment Believed to Treat Sore Throat and IBS

Slippery elm (Ulmus rubra) is a member of the elm tree family that is native to North America. It has been used for centuries in traditional medicine due to its perceived benefits, including the ability to soothe a sore throat, treat wounds, and ease digestive disorder symptoms. However, scientific evidence is lacking.

For health benefits, only the inner bark of slippery elm is used. This is due to substances in the inner bark that increase mucus production in the human body.

Slippery elm contains mucilage, a polysaccharide, or type of fiber that forms a gel-like substance in water. This mucilage is thought to be responsible for many of the proposed benefits of slippery elm.

Unfortunately, research on the positive effects of slippery elm is limited. Many of the existing studies are small and dated.

This article will review the uses of slippery elm, possible side effects, dosage, precautions, and other information regarding how to use slippery elm.

Dietary supplements are not regulated the way drugs are in the United States. This means the Food and Drug Administration (FDA) does not approve them for safety and effectiveness before products are marketed. When possible, choose a supplement tested by a trusted third party, such as USP, ConsumerLabs, or NSF. 

However, even if supplements are third-party tested, that doesn’t mean they are necessarily safe for all or effective in general. Therefore, it is important to talk to your healthcare provider about any supplements you plan to take and check in about potential interactions with other supplements or medications.

Supplement Facts

  • Active ingredient(s): Slippery elm's inner bark and mucilage
  • Alternate name(s): Indian elm, moose elm, olmo Americano, orme, orme gras, orme rouge, orme roux, red elm, sweet elm, Ulmus fulva, Ulmus rubra
  • Legal status: Legal and sold over the counter
  • Suggested dose: No universal dose recommendations for slippery elm
  • Safety considerations: Nausea and skin irritation

Uses of Slippery Elm

Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietitian, pharmacist, or healthcare provider. No supplement is intended to treat, cure, or prevent disease. 

Although research is ongoing, slippery elm may be useful in treating certain health conditions.

In traditional medicine, slippery elm is believed to treat various conditions when taken by mouth or applied to the skin, including:

Other potential uses include the following:

Sore Throat

As a natural demulcent, slippery elm is thought to soothe a sore throat by coating the lining of the throat and esophagus, adding a layer of protection from irritation.

There is a solid amount of anecdotal evidence that slippery elm helps a sore throat. However, science-backed evidence is needed.

In a small pilot study, people who consumed a slippery elm beverage reported a soothing effect of the herbal remedy. Compared to a control group given Lipton tea, those given a hot drink containing slippery elm powder perceived their beverage as soothing at higher rates. The slippery elm was found to be most soothing just one minute after consumption.

More research is needed to prove that slippery elm can truly treat a sore throat.

Inflammatory Bowel Disease

Advocates of slippery elm claim that it can ease many of the symptoms of inflammatory bowel disease (IBD), which includes both ulcerative colitis and Crohn's disease.

Proponents believe slippery elm forms a temporary protective barrier in the intestines. To date, the evidence of this is mixed.

An in vitro study from 2002 found that slippery elm had beneficial antioxidant effects on colon tissue samples from people with ulcerative colitis. However, the researchers could not conclude whether the same effect would occur in human subjects.

Other studies have found slippery elm to be beneficial for IBD and other digestive disorders. However, these studies mostly used slippery elm in combination with other herbs, making it impossible to pinpoint it as a beneficial agent.

Skin Conditions

The mucilage in slippery elm has been used for dry skin or to treat wounds when applied topically.

When applied to the skin, the mucilage in slippery elm is thought to swell and form a gooey substance, which is believed to soothe dry or inflamed skin. This reaction may also prove helpful in the treatment of minor wounds on the skin.

There is insufficient research on slippery elm's use in skin conditions or wound care.

Be sure to speak with your healthcare provider if you're thinking of using topical slippery elm for dry skin or another skin condition.

What Are the Side Effects of Slippery Elm?

Slippery elm is thought to be a safe supplement to take. However, side effects are still possible when using slippery elm.

Common Side Effects

Few side effects have been reported for slippery elm. Although, side effects may still be possible.

There is also not a known correlation between how much slippery elm you take and your risk of side effects. This means taking a higher dose of slippery elm won't necessarily cause side effects.

However, due to the lack of studies on its safety, you should be cautious when using it for the first time. Pregnant people should not use slippery elm, as some reports have indicated harmful effects on the pregnancy.

Despite a lack of evidence, side effects may be possible when taking slippery elm. To decrease your risk of unpleasant side effects, only use slippery elm as directed.

Severe Side Effects

Severe side effects of slippery elm have not been reported.

However, it should be noted that an allergic reaction can occur if slippery elm is used topically. It is possible that applying slippery elm to your skin could cause skin irritation.

To avoid an allergic reaction or other possible severe side effects, talk with your healthcare provider about how to safely use slippery elm.

Slippery elm powder
Verywell / Anastasia Tretiak

Precautions

It's always best to take precautions when using supplements, and slippery elm is no exception.

People who are pregnant or breastfeeding should avoid using slippery elm. This is due to claims that slippery elm can cause a miscarriage.

You should also take precautions if applying slippery elm directly to your skin. Allergic reactions and skin irritation are possible when using topical slippery elm.

There is not enough information to know if slippery elm is safe for children. Therefore, it is recommended that children avoid using slippery elm.

Because research is so limited, there is not enough reliable information on the safety of slippery elm. To be safe, take precautions when using slippery elm and only use it as directed.

Dosage: How Much Slippery Elm Should I Take?

Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your individual needs. 

There are no standard guidelines for the dosage and use of slippery elm.

Slippery elm dosage has varied in the few studies on the herbal remedy. In one small pilot study, just 2 teaspoons of slippery elm powder were used to make a warm beverage to soothe throat pain. Other studies and anecdotal evidence have used much larger doses.

As a general rule, don't take more slippery elm than is recommended on the product label. Taking too much slippery elm could increase your risk of side effects.

Talk to your healthcare provider about the proper dosage for you.

What Happens If I Take Too Much Slippery Elm?

Slippery elm is not thought to be toxic. In the research we do have, slippery elm has been shown to cause little to no side effects.

Regardless, it may be possible to take too much slippery elm, which is why you should always follow the directions on the supplement label. If you take too much slippery elm, you could increase your risk of side effects.

Your healthcare provider can also you on how to take slippery elm safely.

Interactions

Slippery elm may interfere with the absorption and use of certain drugs.

It is recommended that you avoid taking slippery elm at the same time as any oral medications. The mucilage in slippery elm may decrease the absorption and effectiveness of your medications if taken at the wrong time. If you take slippery elm too close to other medications, your body may not be able to properly use the medication as intended.

To prevent this interaction, take slippery elm at least one hour after taking your medications.

There are no known interactions between slippery elm and other supplements or foods.

It is vital that you carefully read the ingredient list and nutrition facts panel of a supplement to know which ingredients and how much of each ingredient is included. Please take precautions and review any supplement labels with your healthcare provider to discuss potential interactions with foods, other supplements, and medications. 

How to Store Slippery Elm

Storing your supplements properly is important. Slippery elm supplements should be stored in a cool, dry place.

Be sure to keep your supplements out of direct sunlight. They should also be kept in an area that is temperature regulated and never gets too hot or too cold.

Typically, slippery elm extract can be stored outside the refrigerator but check the product label to ensure proper storage.

Keep slippery elm supplements out of reach of small children and pets. Discard any old slippery elm supplements that have expired.

Similar Supplements

Many supplements on the market may work similarly to slippery elm.

Similar supplements to slippery elm include:

  • Honey: Raw honey is a well-known treatment for the common cold and sore throat. Like slippery elm, honey is thought to soothe a sore throat. This may be due to its antimicrobial properties.
  • Curcumin: A substance in turmeric spice, curcumin may have antioxidant and anti-inflammatory properties that may benefit people with IBD. In a small study, patients with mild-to-moderate ulcerative colitis (UC) took high-dose curcumin alongside mesalamine, a prescription drug for UC, for one month. Those who took curcumin were found to have more significant improvements in their UC disease activity, as well as remission induction, compared to the placebo group.
  • Collagen: Collagen, a natural protein found and made in your body, may be able to heal dry skin when taken in supplement form. Both oral and topical collagen have been found to improve skin hydration, as well as skin moisture and elasticity.

In most cases, you should only take one supplement for a specific condition at a time. Your healthcare provider can help you choose the best supplements for you.

Frequently Asked Questions

  • Does slippery elm help constipation?

    Although slippery elm is used in traditional medicine for constipation, there is no solid evidence to support these benefits.

    However, it is possible due to the mucilage found in slippery elm. Mucilage is a soft fiber that may work similarly to other types of fiber recommended for constipation relief.

    More research is needed to conclude that slippery elm can relieve constipation.

  • Is slippery elm safe during pregnancy?

    There is not enough information to know for certain that slippery elm is safe for pregnant people to take.

    In fact, there are some claims that slippery elm may cause a miscarriage. Because of this, it is recommended that people who are pregnant avoid using slippery elm.

  • Is slippery elm a diuretic?

    In traditional medicine, slippery elm is sometimes used as a mild diuretic (water pill) to help you urinate. However, there is no scientific evidence to back this up.

    If you need a diuretic, talk with your healthcare provider about a better option than slippery elm.

Sources of Slippery Elm & What to Look For

There are many things to consider when choosing a slippery elm supplement. Slippery elm is not commonly found in foods and is typically used in supplement form.

Food Sources of Slippery Elm

Slippery elm is a tree and, as such, is not naturally found in foods.

It may be possible to chew the bark from the slippery elm tree, but most people use it as a supplement. The bark is said to feel slippery when chewed, most likely due to the mucilage.

Slippery Elm Supplements

Slippery elm supplements are typically made from the inner bark of the tree.

Slippery elm can be purchased in many different forms, including tinctures, lozenges, powders, tea bags, loose-leaf teas, and capsules.

Keep in mind that dietary supplements are not strictly regulated in the United States. They do not need to undergo rigorous testing or research. For the best quality supplements, look for those that have been tested by a third-party agency, like USP or ConsumerLab.

Unfortunately, manufacturers of herbal supplements rarely submit products for third-party testing. This means you may have to use your best judgment when purchasing them. Try not to be swayed by health claims that may or may not be true.

Summary

The inner bark of the slippery elm tree may offer various health benefits. However, many of these are not well supported by scientific evidence.

Few side effects have been reported for slippery elm, and it is generally thought to be safe. Although, some people should take precautions when using slippery elm. Pregnant people should avoid taking it due to potential safety concerns.

If you're interested in taking slippery elm, talk with your healthcare provider first to make sure it is right for you.

8 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading

By Brittany Lubeck, RD
Brittany Lubeck, RD, is a nutrition writer and registered dietitian with a master's degree in clinical nutrition. 

Originally written by
Cathy Wong
Cathy Wong

Cathy Wong is a nutritionist and wellness expert. Her work is regularly featured in media such as First For Women, Woman's World, and Natural Health.

Learn about our editorial process