Quick Summary

Barley Grass (Hordeum vulgare) is a cereal plant recognized for its dietary fiber content and bioactive compounds such as β-glucan. Most clinical evidence mainly pertains to barley grain or barley dietary fiber rather than the grass itself, suggesting potential short-term benefits on postprandial glycemic control and insulin response. Evidence regarding other health indications is preliminary or indirect. More high-quality, long-term clinical trials are necessary to confirm these effects and establish safety and efficacy.

What is it?

Barley Grass is the young, green shoot of the barley cereal plant, Hordeum vulgare. It is consumed as a dietary supplement in powder, juice, or tablet forms. It contains dietary fiber, vitamins, minerals, and various bioactive compounds including β-glucan, which is a soluble fiber predominantly studied in barley grain.

Traditional Uses

Traditionally, barley grass has been used as a nutritive supplement offering vitamins, minerals, and fiber. Barley and its derivatives have been utilized to support digestive health, blood sugar regulation, and lactation, although such traditional applications vary regionally and produce limited clinical validation.

Active Compounds

  • β-Glucan (a soluble dietary fiber)
  • Vitamins (e.g., vitamin C, B-complex vitamins)
  • Minerals (e.g., potassium, calcium, magnesium)
  • Antioxidants and bioactive phytochemicals

Potential Benefits with Evidence Levels

Postprandial Glycemic Control

Evidence Level: Systematic Review and Meta-Analysis of Randomized Controlled Trials

Barley supplementation has been shown to significantly reduce early postprandial blood glucose and insulin levels in healthy adults, reflecting improved short-term glycemic responses. However, no significant long-term effects on fasting glucose or HbA1c were observed.

Key references:
Effect of Barley Intervention on Glycemic Control and Insulin Sensitivity in Adults (2026),
Effect of Barley on Postprandial Blood Glucose in Healthy Individuals (2024),
Barley Consumption and Blood Sugar in Pre-Diabetic Women (2025).

Breastmilk Production in Mothers of Preterm Babies

Evidence Level: Systematic Review of RCTs (Low Certainty)

Low-certainty evidence suggests barley malt combined with lemon balm might increase breastmilk volume in mothers of preterm infants. However, methodological limitations restrict firm conclusions, and further rigorous studies are needed.

Reference:
Herbal Galactagogues to Improve Breastmilk Production (2026).

Irritable Bowel Syndrome (IBS) and Gut Microbiota Modulation

Evidence Level: Narrative Reviews

Barley-based prebiotics, such as germinated barley foodstuff, may help maintain remission in ulcerative colitis and influence gut microbiota in IBS. Evidence remains of very low certainty and further research is warranted.

References:
Prebiotics for Inflammatory Bowel Disease (2025),
Gut Microbiota in Irritable Bowel Syndrome (2025).

Side Effects

No specific safety concerns or serious adverse effects directly related to barley grass or barley-derived dietary fibers have been identified in the reviewed clinical studies. Minimal adverse effects were reported, and no serious events were documented within the studied contexts.

Drug Interactions

There is no documented evidence of drug interactions with barley grass or barley dietary fiber supplements based on currently available clinical data.

Who Should Avoid It?

No contraindications are established on current evidence. However, individuals with specific allergies to barley or related grains, or those with gluten sensitivity or celiac disease, should exercise caution. Due to limited data, pregnant and breastfeeding women should consult healthcare providers before use.

Evidence Limitations

  • Most clinical trials focus on barley grain or barley dietary fiber rather than barley grass specifically.
  • Limited long-term randomized controlled trials on barley grass itself.
  • Many studies involve small sample sizes and short durations.
  • Heterogeneity in study design and outcome measures.
  • Lack of comprehensive adverse event reporting.
  • Unclear dose-response relationships and standardization of interventions.
  • Minimal safety data in pregnancy and breastfeeding.
  • Evidence mostly pertains to related barley products requiring cautious extrapolation to barley grass.

References

Last Reviewed

June 2024

Disclaimer: This information is intended for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before starting any new supplement, especially if you are pregnant, nursing, have existing health conditions, or are taking medications.