Research review
Slippery elm: what the research does and doesn't show
A round-up of the smaller slippery elm health questions with no dedicated review: constipation, diarrhea, pregnancy, libido, fertility, weight and vaginal dryness.
The evidence doesn't support slippery elm, on its own, for constipation, diarrhea, nausea, gas, weight, libido, fertility or vaginal dryness — the smaller questions this site doesn't have a dedicated review for. Here's what's actually been tested, and what hasn't been studied at all.
What the evidence doesn't support
It doesn't support slippery elm as a proven remedy for constipation or diarrhea on its own — the only relevant human research combined it with other active ingredients. It doesn't support any effect on libido, fertility or weight, none of which has been tested in any study found for this page. And it doesn't support using it for vaginal dryness: no trial or mechanism connects an orally taken bark mucilage to vaginal tissue, and no study reviewed across this site tested that use in any form.
What the trials found
A 2010 pilot study split 31 adults with chronic bowel symptoms into two groups by pattern. A formula aimed at looser, more frequent bowel movements (bilberry, slippery elm bark, agrimony, cinnamon) was reported to reduce straining, pain, bloating and flatulence, with a small increase in bowel frequency. A formula aimed at a constipation-leaning pattern (slippery elm bark, lactulose, oat bran, licorice root) was reported to increase bowel frequency and firm up stool consistency. Both were open-label, uncontrolled, and combined slippery elm with two or three other ingredients, so neither result can be credited to slippery elm specifically — see slippery elm and GI disease for the full detail on both studies.
A 2020 study of a seven-ingredient digestive formula that included slippery elm ran 16 weeks in 43 adults and reported broad symptom reductions, again without isolating any single ingredient's contribution. Neither study, nor any other identified for this page, measured libido, fertility, weight change, or vaginal symptoms of any kind.
Where "vaginal dryness" comes from
Slippery elm doesn't appear in any clinical study of vaginal dryness or lubrication reviewed for this page, and there's no proposed biological mechanism connecting a bark mucilage taken by mouth to vaginal tissue. This search term appears to trace back to combination gummy products that pair slippery elm with a probiotic strain and market themselves for women's health generally — see slippery elm and probiotic for what is and isn't known about that pairing. A marketing association between a product and a symptom isn't the same thing as research testing that use.
Pregnancy and breastfeeding
Ask a doctor before using any form of slippery elm if you're pregnant or breastfeeding. There's no dedicated safety research on oral slippery elm in either state, so there's no evidence-based answer in either direction — see who should not take slippery elm for the full caution list.
For dogs
This page and its research cover human use. No veterinary trial was found for this page, so questions about dogs and diarrhea have no research-based answer here — ask a veterinarian.
Questions people ask
Will slippery elm help constipation?
The closest evidence is a formula that paired it with an established laxative (lactulose) and oat bran, which increased bowel frequency in a small, uncontrolled study — a result for the formula, not slippery elm alone.
Can slippery elm cause or help diarrhea?
No trial has isolated slippery elm's own effect on diarrhea. See does slippery elm cause diarrhea, bloating or constipation? for the full picture.
Is slippery elm safe during pregnancy or breastfeeding?
Ask a doctor first. There's no dedicated safety research on oral slippery elm in pregnancy or breastfeeding either way.
Does slippery elm help with vaginal dryness?
No — no clinical study identified for this page tested slippery elm for vaginal dryness or lubrication, and no biological mechanism has been proposed connecting an orally taken bark mucilage to vaginal tissue.
Does slippery elm increase libido or fertility?
No study identified for this page tested either outcome.
Does slippery elm cause weight gain?
No study identified for this page measured weight change from taking slippery elm.
Does slippery elm help with nausea or gas?
Neither symptom was a specific, isolated measurement in the two multi-ingredient formula studies that exist; the 2020 formula study reported a general symptom-severity reduction across a symptom questionnaire that included nausea and gas among many items, but that result belongs to the seven-ingredient formula, not slippery elm alone.
When to talk to a doctor
A change in bowel habits that's new or persistent, pregnancy or breastfeeding questions specific to your situation, or a new or ongoing vaginal symptom are all reasons to see a doctor rather than choosing a supplement aimed at any of them. Slippery elm is not a treatment for any of the conditions or symptoms discussed above.
Related reading: slippery elm benefits: what the research does and doesn't show, slippery elm and GI disease, and who should not take slippery elm.
Sources
- Effects of two natural medicine formulations on irritable bowel syndrome symptoms: a pilot study A small, uncontrolled pilot study found two multi-herb formulas containing slippery elm bark improved IBS symptoms, but neither formula isolated slippery elm's own contribution.
- Herbal formula improves upper and lower gastrointestinal symptoms and gut health in Australian adults with digestive disorders A 16-week uncontrolled study of a seven-ingredient gut-health formula containing slippery elm reported large reductions in GI symptoms, but the formula's other six ingredients make it impossible to credit slippery elm alone.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.