Peppermint extract can improve digestive function through a number of mechanisms, its primary active ingredient menthol (menthol) content typically 40%-60%, may directly affect the gastrointestinal smooth muscle cells on the calcium channel. A double-blinded randomized clinical trial in the Journal of Gastroenterology in 2020 found that 75% of irritable bowel syndrome patients who consumed daily capsules with 180mg peppermint oil lowered abdominal pain incidence by more than 50% and improved rate of intestinal peristalsis by 12% to 15%. The mechanism of action is inhibition of TRPM8 receptor activity, reducing the relaxation pressure of intestinal smooth muscle by 20% to 30%, hence relieving spastic pain. In addition, peppermint extract can induce gastric mucosa secretion bile flow increased by 0.2-0.5mL/min, induce the liposolysis efficiency up to 18%-22%. University of Munich research in Germany confirmed 0.2mL/kg peppermint oil in lowering gastric empting time from a mean of 120 minutes to 94 minutes and reducing the incidence of gastroesophageal reflux by about 35%.
Market size for therapeutic uses, i.e., digestive AIDS with peppermint extract, will reach $470 million in 2021 with a compound annual growth rate of 18.3%. For example, in the US, FDA has approved IBGard® capsule with multi-matrix sustained-release technology, a single capsule of 182mg peppermint oil, 62% of patients in clinical trials had reduction in frequency of abdominal distension ≥3 times/week after 4 weeks of therapy. From the point of view of costs and benefits, the use of peppermint extract instead of traditional antispasmolytics will reduce the treatment cost by 30-40% as the raw material price is just 80−120 per kg while the raw material price of synthetic medicine can go up to $450/kg. A University of Nottingham study conducted in the UK also found that peppermint extract reduced the release of the intestinal inflammatory factor TNF-α by 42% by inhibiting the 5-HT3 receptor, and this effect increased the size of the lesion to 28.6% in models of Crohn’s disease.
According to market research, more than 67% of all international consumers prefer gastrointestinal health products with natural peppermint oil, which is 23 percentage points higher than chemically formulated products. In the pharma sector, Dr. Willmar Schwabe of Germany’s PEON series of products has increased menthol bioavailability to 92% with the help of nanoemulsification technology, with peak plasma concentration at 15 minutes after a one-time dose (Cmax=1.8μg/mL). It can be noted that when simultaneously used with peppermint extract and probiotics, intestinal flora diversity Index (Shannon Index) can be increased by 0.7-1.2, and proliferation rate of bifidobacterium is encouraged by 3.2 times. Such synergy effect has been verified in the study “Frontiers in Nutrition” in 2022, and the improvement rate of patients’ defecation frequency in the combined regimen group has reached 81%. Much higher than 54% in the monotherapy group.
With respect to safety measures, peppermint extract’s LD50 was 2420mg/kg (oral intake by rats), and the incidence of adverse reactions with the suggested dosage (0.1-0.3mL/time) was only 2.3%, much lower than the 11.6% of anticholinergic drugs. But it must be noted that it can reduce lower esophageal sphincter pressure (from 15mmHg to 9mmHg at baseline), thus enteric coating has to be given in patients with GERD. Historical statistics show that, in ancient Rome, historical accounts of moistening mint leaves in wine (concentration level approximately 5%) were used to rectify indigestion, while today chromatographic evidence demonstrates that content of menthone in peppermint oil from steam distillation is constant in the range 14%-18%, being the primary active ingredient for carding effect. The current industry trends reflect that the global application of peppermint extract in the digestive health segment is increasing at 9.8% annual growth, and the size of the market will exceed 620 million US dollars by 2025.