Improved glycemic control in patients with advanced type 2 diabetes mellitus taking Urtica dioica leaf extract: a randomized double-blind placebo-controlled clinical trial

Clin Lab. 2013;59(9-10):1071-6. doi: 10.7754/clin.lab.2012.121019.


Background: Advanced type 2 diabetes mellitus (T2DM) needing insulin therapy is common. Most conventional anti-hyperglycemic drugs have limited efficacies and significant side effects, so that better anti-hyperglycemic agents are needed. Urtica dioica L. (nettle) leaves have insulin secretagogue, PPARgamma agonistic, and alpha-glucosidase inhibitory effects. Moreover, nettle leaves are used in traditional medicine as an anti-hyperglycemic agent to treat diabetes mellitus. Thus, efficacy and safety of nettle in the treatment of patients with advanced type 2 diabetes mellitus needing insulin were studied.

Methods: In this randomized double-blind placebo-controlled clinical trial, we evaluated the effects of taking nettle leaf extract (one 500 mg capsule every 8 hours for 3 months) combined with the conventional oral anti-hyperglycemic drugs on the blood levels of fasting glucose, postprandial glucose, glycosylated hemoglobin (HbA1c), creatinine and liver enzymes SGOT and SGPT, and systolic and diastolic blood pressures in 46 patients and compared with the placebo group (n = 46).

Results: At the endpoint, the extract lowered the blood levels of fasting glucose, 2 hours postprandial glucose, and HbA1c significantly (p < 0.001, p = 0.009, and p = 0.006, respectively) without any significant effects on the other parameters (p > 0.05) compared with placebo.

Conclusions: Nettle may safely improve glycemic control in type 2 diabetic patients needing insulin therapy.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alanine Transaminase / blood
  • Aspartate Aminotransferases / blood
  • Blood Glucose / analysis*
  • Creatinine / blood
  • Diabetes Mellitus, Type 2 / drug therapy*
  • Double-Blind Method
  • Female
  • Glycated Hemoglobin / analysis
  • Glycoside Hydrolase Inhibitors
  • Humans
  • Hypoglycemic Agents / therapeutic use*
  • Male
  • Middle Aged
  • PPAR gamma / antagonists & inhibitors
  • Placebos
  • Plant Extracts / therapeutic use*
  • Plant Leaves / chemistry
  • Urtica dioica / chemistry*


  • Blood Glucose
  • Glycated Hemoglobin A
  • Glycoside Hydrolase Inhibitors
  • Hypoglycemic Agents
  • PPAR gamma
  • Placebos
  • Plant Extracts
  • hemoglobin A1c protein, human
  • Creatinine
  • Aspartate Aminotransferases
  • Alanine Transaminase