Benefits
Soothing film for the mouth and throat in EU traditional use
Mallow leaf and flower teas are registered in the EU as traditional herbal medicines, used as a demulcent for an irritated mouth or throat and the dry cough that can come with it, in adolescents and adults. That status rests on at least 30 years of documented use. EU assessors found no clinical studies of this use.
Bowel movement frequency and stool form in a placebo trial of flower syrup
In adults with functional constipation (110 started, per EU reviewers), 4 weeks of a mallow flower water extract syrup (1 g of extract a day) raised weekly bowel movements and reduced hard stools and other symptoms more than a placebo syrup. Symptoms were self-reported. EU reviewers did not use the trial because no such product is sold in the EU.
Traditional demulcent for mild stomach and gut discomfort
EU regulators also accept mallow leaf and flower tea for mild stomach and gut discomfort in adolescents and adults, based on long-standing use alone. The placebo trial above looked at bowel habit, not this kind of discomfort, so for this use mallow remains a traditional remedy.
Bowel habit in an uncontrolled survey of a mallow food supplement
In 56 adults with constipation who took a drinkable supplement with 750 mg of mallow extract daily for 20 days, weekly bowel movements roughly doubled from baseline and stool form and belly pain scores improved. There was no comparison group, and each daily dose also held 10 g of sorbitol, a sugar alcohol that draws water into the gut.
Cough scores in children given multi-herb syrups that include mallow
In two placebo-controlled trials in children, honey-based syrups combining mallow with three or six other herbs lowered cough scores more than placebo over 5 to 8 days. One placebo lacked the honey and all herbs, so neither trial shows what mallow adds on its own.
Mallow mucilage and the cough reflex in cat tests
As summarized by EU reviewers, mucilage and a rhamnogalacturonan fraction from mallow flowers (Malva mauritiana), given by mouth to cats at 50 mg/kg, reduced coughing triggered by touching the larynx and airways, and no slowing of breathing was noted. These are animal results only.
Laxative and colon effects of leaf and aerial part extracts in rats
In rats given loperamide, a drug that slows the gut, a mallow leaf water extract given by mouth increased stool output and sped gut transit, and water fractions and a mallow polysaccharide given by mouth reduced chemically induced colon inflammation. Rat doses of 100 to 400 mg/kg were used. Neither result has been tested in people.
Mechanism of action
Swelling Acidic Polysaccharide Mucilage
Mallow leaves and flowers hold mucilage built from high molecular weight acidic polysaccharides (about 1.3 to 1.6 million daltons) of glucuronic and galacturonic acid, rhamnose and galactose. In water these swell into a viscous gel thought to coat the mouth and throat. Uronic acids are richer in the flower (about 23 percent) than the leaf (about 8 percent).
Mucilage and Fiber in the Gut
In rats, a leaf water extract taken by mouth increased gut transit and stool water, and an isolated mallow polysaccharide reduced induced colon inflammation. A commercial mallow extract contained both soluble and insoluble fiber. Whether these effects explain the bowel changes reported in people is not known.
Anthocyanins of the Flower
The purple flowers carry anthocyanins, mainly malvidin glucosides, at about 0.4 to 7.3 percent of dry weight. Applied to mouse skin, malvidin 3-glucoside reduced induced swelling and white cell influx. No study has measured anthocyanin uptake or any effect after drinking mallow tea.
Clinical trials
Placebo-controlled trial in Iran of a syrup made from a water extract of Malva sylvestris flowers in sugar solution; registered as IRCT2014031617032N1; described as randomized in the EMA assessment report (the abstract says only that participants were allocated); blinding not described in the abstract (Elsagh et al. 2015, Complement Ther Clin Pract)
110 adults with functional constipation who started treatment (55 per group, per the EMA assessment report)
Taking 10 ml of syrup twice daily (1 g of extract a day, dosing per the EMA assessment report) for 4 weeks raised defecation frequency and lowered the frequency of all constipation symptoms more than placebo (between-group F tests, P < 0.001), with a larger reduction in the frequency of hard stool forms (45.4 vs 9.1 percent). Per the EMA assessment report, on the syrup 4 people had diarrhea, 4 acid regurgitation, 2 nausea, and single cases of worse constipation, upper belly pain, heartburn and hives. EU reviewers did not use it because no such product is on the EU market.
Questionnaire-based consumer survey in Italy of Laxamov, a drinkable supplement made by Labomar with 750 mg Malva sylvestris extract and 10 g sorbitol per 20 ml daily dose, in adults with functional constipation who kept a daily diary of bowel movements, stool form (Bristol scale) and abdominal pain; no placebo, randomization or blinding (Lellis et al. 2024, Nutrients)
56 adults (12 men, 44 women) who took the supplement for 20 days on a pharmacist's advice
Mean weekly evacuations rose from 3.2 to 6.0 in men and from 2.6 to 5.2 in women, and Bristol scale and abdominal pain scores improved from baseline; no adverse effects were reported. The authors judged the sorbitol below a laxative dose, but with no comparison group and self-reported diaries, the change cannot be credited to mallow.
Randomized, double-blind, placebo-controlled trial of KalobaTUSS, a medical device syrup of acacia honey with extracts of mallow leaf, elecampane, plantain and Helichrysum; four authors employed by Schwabe Pharma Italia; registered retrospectively (Carnevali et al. 2021, BMC Pediatr)
106 children aged 3 to 6 with acute cough for at least 3 days (54 syrup, 52 placebo)
At 5 ml four times daily for 8 days, night and day cough scores fell more on the syrup, and after 8 nights 7 of 54 children still had night cough versus 22 of 52 on placebo. No adverse events occurred. The placebo was a fructose syrup with no honey or herbs, so honey alone could explain part of the effect, and mallow's share cannot be judged.
Double-blind, randomized, placebo-controlled trial in Mashhad, Iran, of a syrup made from chamomile, marshmallow flower, mallow flower, hyssop, maidenhair fern, licorice and jujube with honey and manna (Javid et al. 2019, Avicenna J Phytomed)
46 children aged 7 to 12 with intermittent asthma, treated from the start of a common cold
Taken as 5 ml three times daily for 5 days, the syrup reduced cough severity and night awakenings more than placebo. Wheezing, breathing rate, peak flow, reliever and steroid use, school absence and hospital visits did not differ. No side effects were reported. With seven herbs and honey, no effect can be credited to mallow.
Animal study of an aqueous Malva sylvestris leaf extract given by mouth to rats made constipated with loperamide. No human participants (Jabri et al. 2017, Biomed Pharmacother)
Male Wistar rats in six groups of six
At 100, 200 and 400 mg/kg, the extract reduced the loperamide effects in a dose-dependent way, judged by fecal weight, frequency and water content, increased transit and lowered colon oxidative stress markers. These rat doses and results have not been tested in people.
Animal study of aqueous, ethanolic and n-hexane fractions of Malva sylvestris aerial parts and an isolated polysaccharide, each given by mouth to rats before or after colon inflammation was induced with rectal acetic acid. No human participants (Hamedi et al. 2016, J Evid Based Complementary Altern Med)
Male rats in 8 groups of 6, given 200 mg/kg a day by mouth (per the EMA assessment report)
The aqueous fraction was the most effective at preventing visible and microscopic inflammation, the ethanolic and n-hexane fractions less so, and the polysaccharide reduced inflammation mainly when given beforehand. This is a chemically induced model in rats and does not show an effect in people.