Glycyrrhiza glabra


Other Names:



  • Antiviral
  • Antiulcer
  • Anti-inflammatory
  • Antioxidant
  • Antitumor
  • Antibacterial
  • Immunity
  • Gastroprotective
  • Heptoprotective
  • Neuroprotective
Licorice (Glycyrrhiza glabra) root is a perennial herb which has a long history of use in ancient Assyrian, Egyptian, Chinese, and Indian cultures. It is sold as a dietary supplement for digestive and respiratory issues and bacterial and viral infections. It also often an ingredient in some products for topical use.

Licorice root is sold as a powder, extract, or in capsules. Potential side effects of licorice root, if given in large amounts or over a long period of time include increased blood pressure and decreased potassium levels. These effects may be a concern for birds with heart or kidney disease.

Specific applications studied in poultry include:
  • Antiviral: Licorice possesses some antiviral activity in vitro toward a number of viruses---including Newcastle disease virus (NDV) in chickens and Duck Hepatitis Virus (DHV) in ducks. In a study conducted on 40 day-old white Pekin domestic ducklings, treatment with glycyrrhizin alone or with DHV vaccine demonstrated to be an effective immune system booster and had an antiviral effect against DHV.
  • Gut health: Adding licorice extract to the diet at 1 g/kg of diet improved the growth performance of broiler chickens, as well as influenced the maintenance of intestinal integrity and reduced Campylobacter jejuni shedding from infected birds. (D Ibrahim et al., 2020)

Poultry Specific Studies

TypePlant PartDosageSpecific useResultsRef
OtherMycoplasmaAttenuated tracheal and lung damage caused by Mycoplasma invasion. Can inhibit MG-triggered inflammation and apoptosis by suppressing the expression of MMP2/MMP9 through the JNK and p38 pathways and inhibit the expression of virulence genes to resist MG. Results suggest it might serve as one of the antibiotic alternatives to prevent MG infection.Y Wang et al., 2022
Broilersextract0.4 g/L in drinking waterimmunityImproved body weight, weight gain, feed intake, and FCR. Licorice also exhibits a broad range of biological activities such as hypolipidemic, hypoglycemic, hepatoprotective, immunostimulant, and antioxidant effects. The morphometric analysis of different parameters of the intestine revealed a significant increase in the intestinal villi length, width, and villi length/crypt depth in the group supplemented with licorice 0.4 gm/L compared to other groups. The number of CD3 positive in both duodenum and ileum was increased in the licorice 0.4 gm/L group compared to other groups. The expression of growth-related genes was significantly increased with licorice supplementation and modulation of the lipid metabolism genes in the liver and upregulated to the mRNA expression of both superoxide dismutase (SOD1) and Catalase (CAT). Our results revealed that licorice supplementation increased the growth performance of broiler chickens and impacted the birds’ antioxidant activity through modulation of the growth-related genes, lipid metabolic markers, and antioxidant-related pathwaysM Abo-Samaha et al., 2022
Chickensextract450 mg/kg dietantioxidant, aflatoxicosishelped diminish the detrimental effects of aflatoxins in feed.H Al-Daraji et al.,2012
Quailpowder750-1000 mg/kg dietGI healthResulted in marked reductions in the number of total bacteria, coliforms, E. coli, and Salmonella. Enhanced performance, immunity, antioxidant capacity, and maintains a healthy gut microbiota.F Reda et al., 2021
Broilersextract1 g/kg of dietgut health, Campylobacter jejuniImproved the growth performance and influenced the maintenance of intestinal integrity and reduced Campylobacter jejuni shedding from infected birds.D Ibrahim et al., 2020
Chickensextract0.4% in drinking waterantioxidantreduced abdominal fat accumulation.J Salary et al., 2014