Awaiting clinical review. This entry is sourced but has not yet been signed off by a pharmacist or clinician.

Ulmus rubra (inner bark)

Slippery elm

Slippery elm is a traditional soothing remedy for sore throat and an upset gut, but we found no controlled trial of the bark on its own, so whether it works is unknown. The US liver-injury database describes it as generally recognised as safe with no evidence of liver harm. The main gap is dosing: no source we opened gives a tested amount of slippery elm alone, and safety in pregnancy is not established.

Written by

Healthy and Herbal editorial team

Updated

29 September 2026

At a glance

Last reviewed 29 September 2026

Evidence

Traditional

Best for

Sore throat, gut upset

Typical form & use

Powdered bark; no dose established

Onset

About a week

Safety

No proven dose; safety in pregnancy unknown. No interactions in our data.

Check with your medications →

What it's used for

Evidence is rated per use. The same ingredient can be strong for one thing and traditional for another.

Use	Evidence	What the research shows
Sore throat	Traditional	The inner bark is used by mouth for sore throat as a traditional demulcent (a soothing, coating remedy). We found no trial of slippery elm alone for sore throat. A randomised trial of a multi-herb demulcent tea in 60 adults with acute pharyngitis found less throat pain than placebo, but the abstract does not say the tea contained slippery elm, so we cannot credit it to this herb.^1,6
Upset stomach and irritable bowel symptoms	Traditional	Traditionally used for gastrointestinal upset. The only human data we found are uncontrolled studies of multi-ingredient products that contained slippery elm: a 31-person open-label IBS pilot with two blends, and a 43-person before-and-after study of a curcumin, aloe, guar gum, pectin and peppermint blend. Both reported symptom improvements, but with no placebo group and other active ingredients, the results say nothing reliable about slippery elm itself.^1,2,3
Heartburn and reflux	Traditional	A 2019 review lists slippery elm among popular remedies for oesophageal symptoms and concludes there is a substantial gap between anecdote and empirical evidence for most such remedies. We only read the abstract, which does not give slippery-elm-specific findings.⁴
Skin irritation and rash (applied to skin)	Traditional	LiverTox notes the inner bark is used topically for skin rash and irritation. We found no clinical research on this use.¹

How much

Ranges below are what studies used and what supplements commonly contain. They are not a recommendation for you. Start at the low end.

Slippery elm alone

No established dose

None of the sources we opened gives a tested dose of slippery elm on its own. Follow the product label and treat any stated dose as a manufacturer choice, not a studied one.

Multi-ingredient study dose

5 g then 10 g a day of a blend³

One uncontrolled study gave a blend containing slippery elm at 5 g a day, then 10 g a day, for 4 weeks each. The slippery elm share of that blend is not stated in the abstract.

Timing · No source we read gives timing advice for slippery elm.With food? · No source we read gives food advice. Traditional preparations are mixed with water into a thick, slippery drink or paste.How long to trial · No trial period is established for slippery elm alone. The one uncontrolled multi-herb study we read ran for 4 weeks at each dose. If symptoms persist or worsen, see a doctor rather than extending use.

How people take it

Powdered bark, mixed with waterFollow the product label; no studied doseThe traditional oral preparation. Not tested on its own in any trial we found.

Herbal tea or lozengeFollow the product label; no studied doseCommonly sold for sore throat. Products often combine several herbs, so trial results for a blend do not transfer to slippery elm.

Powder or paste applied to skinNo studied doseA traditional topical use noted by LiverTox; no clinical evidence found.

Safety

Who should avoid

Pregnancy and breastfeeding — no safety data we could source, ask your clinician
Persistent or severe sore throat, or trouble swallowing or breathing — see a doctor
Ongoing gut symptoms, blood in stool or weight loss — get them checked first

Known interactions

No interactions in our data. Absence of a flag is not clearance.

Questions people ask

Does slippery elm work for sore throat?

Nobody knows yet. It is a traditional soothing remedy, but we found no trial of slippery elm alone for sore throat. A trial of a multi-herb tea showed pain relief over placebo, but it cannot be credited to slippery elm specifically.

Is slippery elm safe?

LiverTox describes slippery elm preparations as generally recognised as safe and reports no evidence that it raises liver enzymes or causes clinically apparent liver injury. That is a statement about liver injury; it is not a full safety review, and pregnancy safety has not been established.

Does slippery elm help irritable bowel syndrome or reflux?

The evidence is not strong enough to say. The human studies we found were small and uncontrolled and tested blends of several ingredients, and a 2019 review found little empirical evidence behind most popular reflux remedies.

Should I take slippery elm apart from my medicines?

It is often advised because a coating fibre could in theory slow absorption, but none of the sources we opened says so, so we cannot confirm it. Ask a pharmacist if you take medicines where timing matters.

Sources

Last reviewed 29 September 2026 · Next review March 2027 · How we rate evidence