Supplement
Slippery elm is the inner bark of a North American tree, rich in mucilage, a gel-like fiber that coats and soothes the throat and gut. People mainly look at it for digestive complaints and sore throat, yet the evidence is limited, and no controlled trials have tested it alone for either. Existing research is mostly lab work on herbal extracts that found antioxidant compounds, which says little about how people feel.
Sources: PMID 19609882; PMID 21783752
- Updated
- How we grade
- 2 studies cited
- Best evidence
- Grade D
- Conditions studied
- 3
- Outcomes
- 4
- Graded outcomes
- 0004
Evidence by condition
- Strong
- Moderate
- Limited
- Very limited
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Antioxidant Activity In vitro characterization of Flor-Essence, a compound herbal product containing slippery elm bark among other herbs, identified phenolic compounds with antioxidant properties. However, the contribution of slippery elm specifically versus other ingredients was not isolated, and no in vivo or clinical evidence exists. | Improves (the measure goes up) | Small effect | 2 studies | |||
Studies that measured antioxidant activity | ||||||
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Sore Throat Symptom Relief No controlled clinical trials specifically evaluate slippery elm for sore throat. The mucilage content provides a plausible mechanical coating/soothing mechanism, and slippery elm is a common ingredient in commercial throat lozenges, but direct clinical evidence is absent. Efficacy is inferred from traditional use and the well-characterized demulcent properties of plant mucilage. | Changes; see studies | Small effect |
General
- Gastrointestinal Symptom Relief: changes; see studies
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Gastrointestinal Symptom Relief No controlled clinical trials isolate slippery elm's effect on GI symptoms. Slippery elm is included in some combination products for IBS and reflux, but its individual contribution has not been established. The mucilage coating mechanism is plausible for symptomatic relief of GI irritation, but evidence remains limited to traditional use and mechanistic rationale. | Changes; see studies | Small effect |
Acute Bronchitis
- Cough Symptom Relief: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Cough Symptom Relief No clinical trials evaluate slippery elm for cough suppression or relief. Traditional use as a demulcent for coughs is long-standing, and the mucilage coating mechanism is plausible for soothing irritated upper airways, but no modern clinical data supports this indication specifically. | Improves (the measure goes down) | Small effect |
Key findings
- Antioxidant ActivityImproves (the measure goes up)
- Sore Throat Symptom ReliefChanges; see studies
- Gastrointestinal Symptom ReliefChanges; see studies
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- Grade D
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Studies cited
2 studies from PubMed