An extract of artichoke leaf has undergone considerable study in the last few years as a treatment for a variety of conditions, most prominently high cholesterol. Artichoke leaf is one of many herbs thought to stimulate gallbladder function.⁷ In 2003, a large (247-participant) study evaluated artichoke leaf as a treatment for dyspepsia.²⁴ In this carefully conducted study, artichoke leaf extract proved significantly more effective than placebo for alleviating symptoms of functional dyspepsia. A study of an herbal combination containing artichoke leaf is described below.

For more information, including dosage and safety issues, see the full Artichoke article.

The spice turmeric contains a substance, curcumin, that may stimulate gallbladder contractions.^2,3 A double-blind, placebo-controlled study including 106 people compared the effects of 500 mg of curcumin 4 times daily against placebo (as well as against a locally popular over-the-counter treatment). After 7 days, 87% percent of the curcumin group experienced full or partial symptom relief from dyspepsia as compared to 53% of the placebo group.⁴

For more information, including dosage and safety issues, see the full Turmeric article.

Several studies, enrolling a total of more than 600 participants, have found benefits with a proprietary herbal combination therapy containing bitter candytuft ( Iberis amara) as the major active ingredient.^{22,25,26,27,31} The largest of these was an 8-week, double-blind study of 315 people with functional dyspepsia, in which the candy tuft product proved significantly more effective than placebo.³¹

A double-blind trial of 60 people given either placebo or a combination of artichoke leaf, celandine and boldo found improvements in symptoms of indigestion after 14 days of treatment.⁷ Similarly positive effects were seen in a double-blind trial of 76 individuals given a combination treatment containing turmeric and celandine.⁸

Note: Reports have raised concerns that celandine can damage the liver.^9-11 In addition, boldo is dangerous for use by pregnant women, or individuals with liver or kidney disease.

Herbs believed to assist in the passing of gas are traditionally called "carminatives." Classic carminatives include caraway, chamomile, dill, fennel, peppermint, spearmint, and turmeric. Essential oils made from some of these herbs have been studied for the treatment of dyspepsia.

For example, a double-blind, placebo-controlled study including 39 individuals found that an enteric-coated peppermint-caraway oil combination taken 3 times daily for 4 weeks significantly reduced dyspepsia pain as compared to placebo.¹² Of the treatment group, 63.2% was pain free after 4 weeks, compared to 25% of the placebo group.

Results from a double-blind comparative study including 118 people suggest that the combination of peppermint and caraway oil is comparably effective to the standard drug cisapride, which is no longer available.¹³ After 4 weeks, the herbal combination reduced dyspepsia pain by 69.7%, whereas the conventional treatment reduced pain by 70.2%.

A preparation of peppermint, caraway, fennel, and wormwood oils was compared to metoclopramide in another double-blind study enrolling 60 individuals.¹⁴ After 7 days, 43.3% of the treatment group was pain-free compared to 13.3% of the metoclopramide group. Metoclopramide works by reducing gastric emptying time (in other words, speeding the passage of food from the stomach into the intestines). Interestingly, some evidence suggests that peppermint oil may have the same effect.³²

Note: Essential oils of herbs can present health risks. In particular, wormwood (the herb in absinthe) is dangerous when taken long term. Physician supervision is strongly recommended. See the Essential Oil article for more information.

Preliminary evidence suggests that oral use of the herb cayenne can reduce the pain of dyspepsia. This may seem like an odd use of the herb; intuitively, it seems that hot peppers should be hard on the stomach. However, contrary to popular belief, hot peppers don’t actually inflame the tissues they contact; in fact, hot peppers aren’t even harmful for ulcers! ²⁰ Rather, they merely produce sensations similar to those caused by actual damage.

Here’s how it works: All hot peppers contain a substance called capsaicin. When applied to tissues, capsaicin causes release of a chemical called substance P. Substance P is ordinarily released when tissues are damaged; it is part of the system the body uses to detect injury. When hot peppers artificially release substance P, they trick the nervous system into thinking that an injury has occurred. The result: a sensation of burning pain. When capsaicin is applied regularly to a part of the body, substance P becomes depleted in that location. This is why individuals who consume a lot of hot peppers gradually build up a tolerance. It’s also the basis for a number of medical uses of capsaicin. When levels of substance P are reduced in an area, all pain in that area is somewhat reduced. Because of this effect, capsaicin cream is widely used for the treatment of painful conditions such as shingles, arthritis, and diabetic neuropathy.

Oral use of capsaicin may also reduce discomfort in the stomach. In a double-blind study, 30 individuals with dyspepsia were given either 2.5 g daily of red pepper powder (divided up and taken prior to meals) or placebo for 5 weeks.²¹ By the third week of treatment, individuals taking red pepper were experiencing significant improvements in pain, bloating, and nausea as compared to placebo, and these relative improvements lasted through the end of the study.

A controlled (but not blinded) study of 46 people suggests that banana powder, a traditional Indian food, may help treat dyspepsia. After 8 weeks of treatment, 75% of the people taking banana powder reported complete or partial symptom relief compared to 20% of those who received no treatment.¹⁵

Herbs with a reputation for relaxing a nervous stomach, such as chamomile, valerian, and lemon balm, are also sometimes recommended for dyspepsia. Numerous other herbs that have been recommended for dyspepsia include angelica root, anise seed, barberry, bitter orange peel, blessed thistle, cardamom, centaury, chicory, dandelion root, cinnamon, cloves, coriander, devil's claw, dill, gentian, ginger, horehound, juniper, linden, milk thistle, radish, rosemary, sage, St. John's wort, star anise, and yarrow.

A tea made from the "fruits" or seeds of parsley is a traditional remedy for colic, indigestion, and intestinal gas.^18,19

Reduced levels of digestive enzymes may play a role in dyspepsia. One double-blind study found that use of pancreatic enzyme supplements improved symptoms following consumption of a high-fat meal.²³ However, another placebo-controlled study failed to find pancreatic enzymes helpful for dyspepsia symptoms in general.¹⁶

Very weak evidence hints that melatonin might be helpful for dyspepsia.²⁹

One study failed to find probiotics (friendly bacteria) helpful for dyspepsia in children.²⁸

Two studies failed to find the carotenoid astaxanthin more effective than placebo for the treatment of stomach irritation in people with dyspepsia.^30,33

Betaine hydrochloride increases the acidity of the stomach, and on that basis it has been proposed as a digestive aid for people with inadequate stomach acid. However, there is no evidence that reduced stomach acid levels causes symptoms of indigestion.