Iberogast® for Healthcare Professionals

Scientific Evidence

Iberogast is registered as an OTC medicine for the treatment of functional gastrointestinal symptoms including those of Functional Dyspepsia and Irritable Bowel Syndrome (IBS).8 There are a multitude of double-blind and randomised studies versus placebo or active control, as well as some meta-analyses. In these clinical trials, the efficacy and safety profile of Iberogast was demonstrated.13,14,17,20,24

Summary of clinical evidence

The efficacy and safety of Iberogast for the treatment of functional digestive symptoms have been proven in a large number of studies with more than 50,000 participants in total.17 Using quantifiable criteria, the excellent efficacy and tolerability of Iberogast was verified at the highest level of scientific evidence.24

In summary, the Iberogast studies showed:

  • Significant efficacy for the treatment of functional digestive symptoms
  • Equivalent efficacy to prokinetic substances20
  • Tolerability comparable to placebo
  • Established safety profile
  • Fast onset – onset of relief starts between 15 and 30 minutes after intake.

Proof of high efficacy

Clinical evidence in IBS & Functional Dyspepsia


In a clinical trial of 208 patients with Irritable Bowel Syndrome (IBS), digestive symptoms and abdominal pain, those using Iberogast were shown to have their symptoms significantly reduced after 2 and 4 weeks treatment.13

Iberogast is significantly better than placebo in reducing the total abdominal pain score. (Madisch A et al. 2004)

Gastrointestinal Symptom Score (GIS)
Adapted from Madisch et al. 2004

Change of the abdominal pain score during 4 weeks of therapy with Iberogast® or placebo


In a combined analysis of three separate trials in FD with 273 individuals, 60% of patients in the Iberogast group reported their most bothersome symptom as mild or absent vs. only 24% of patients in the placebo group.

Pooled data showed Iberogast to be more effective than placebo with regard to the severity of the most bothersome gastrointestinal symptom.14 (Melzer J et al. 2004).

Adapted from Metzer J et al. 2004


Clinical evidence of fast onset of action. Major onset of therapeutic effects was observed between 15 and 30 minutes after taking Iberogast. In a clinical study of 272 patients, Iberogast began to relieve functional digestive symptoms within minutes of administration.25 (Vinson BR et al. 2013 poster)

Adapted from Vinson et al. 2013

Proof of excellent tolerability & established safety

In a placebo-controlled clinical trial of 208 patients with functional digestive symptoms, an assessment of tolerability was conducted.

94% of the patients assessed tolerability of Iberogast to be ‘good‘ or ‘very good‘. Again, no safety-relevant changes of laboratory parameters were observed. (Madisch A et al. 2004)

Assessment of the tolerability by the patient

Adapted from Madisch A. et al. 2004

In a number of different studies the acute, chronic, subchronic and reproductive toxicity, mutagenic effects and cytotoxicity of Iberogast were tested. All toxicological studies were carried out with Iberogast that are required in accordance with the current international guidelines (ICH, OECD, FDAJap. MHW) for new marketing authorisation of a medicine (NCE). These studies did not show any toxic or mutagenic effects, thus further confirming the established safety profile of Iberogast.

Therapeutic recommendation for FD by ROME IV

The ROME Foundation is an independent not-for-profit organisation with the mission: "Improving the lives of people with functional GI disorders". Over the last 17 years, this organisation developed global recommendations for diagnosing and treating FGIDs. Their directives are updated regularly and represent eminently respected guidance. In the recent “ROME IV” publications, issued by special working groups of renowned gastroenterologists, Iberogast (STW 5) is recommended for the treatment of patients with Functional Dyspepsia.28

Clinical management of patients affected by functional dyspepsia
                                                           STW5 = Iberogast

Stanghellini et al. 2016: Clinical management of patients affected by functional dyspepsia