Fennel seeds may help reduce gas due to their anti-inflammatory properties and high fiber content. However, more research is needed to fully support their digestive benefits.

Fennel seeds (Foeniculum vulgare Mill) are long, thin, pale green seeds with a sweet, licorice-like taste and scent.

In many parts of the world, people chew plain or sugar-coated fennel seeds after a meal because it’s thought to help aid digestion and prevent gas.

Research suggests that fennel seeds may have anti-inflammatory, antioxidative, and antibacterial properties that could help fight certain conditions.

Some studies have also examined the digestive effects of fennel seeds on animals and have found several ways they may help relieve gas. However, few studies have examined their effects on humans.

Keep reading to learn more about how fennel seeds may help prevent or reduce gas.

Fennel seeds may help relieve gas in several ways.

Fiber-rich

Fennel seeds pack a lot of fiber in their tiny forms.

A tablespoon (5.8 grams [g]) of dried fennel seeds provides 2.3 g of fiber. By comparison, a medium apple (183 g) has 4.4 g of fiber.

A 2023 review found that fiber is key in reducing bloating, which is most commonly caused by excessive gas.

Fennel seeds also contain insoluble fibers, which could help reduce the amount of gas produced in your gut and associated symptoms like farting (flatulence).

The United Kingdom’s National Health Service recommends eating fiber-rich foods if you’re experiencing bloating and constipation.

The recommended daily amount of dietary fiber is 30 g, according to the British Heart Foundation.

Digestive aid

Fennel seeds have anti-inflammatory properties that may help soothe swelling or irritation in the intestines and improve digestion.

According to a 2017 review, a chemical in fennel called anethole may help relax the muscles of the gastrointestinal tract. This may help relieve bloating and improve digestion.

Fennel may also help relieve symptoms associated with digestive conditions like irritable bowel syndrome (IBS), including:

According to a 2016 review, a combination of fennel seeds, sodium bicarbonate, and syrup is sometimes used to make gripe water to help relieve gas in children.

Antimicrobial

Several components available in fennel have antibacterial and antifungal properties. These might help fight bacteria that may cause gassiness associated with food poisoning or an upset stomach.

However, more research is needed to determine the effects of fennel seeds in relieving gas and gastrointestinal symptoms caused by bacteria.

Fennel seeds contain higher concentrations of oils than the fennel plant. For this reason, you only need to use between 1 teaspoon and 1 tablespoon (2 to 6 g) of dried, whole fennel seeds in most recipes.

Some ways to include fennel seeds in your diet include:

  • making tea with fennel seeds
  • adding toasted fennel seeds to dishes to give them a sweet, licorice flavor
  • adding seeds to batter for baked goods
  • taking fennel supplements

Before cooking or brewing a fennel tea, consider crushing or grinding whole fennel seeds just before using them. This helps release more of the oil and flavor.

Fennel seeds are generally safe to consume.

However, like other herbs and seeds, fennel seeds contain oils that can be extracted into concentrated forms. All natural oils contain powerful chemicals and may cause side effects if you use too much.

Some possible side effects of using fennel seeds may include:

It’s also possible to be allergic to fennel seeds.

When to see a doctor

Speak with a healthcare professional if you’re bloated or experience other gastrointestinal symptoms for 3 weeks. This may be a sign of an underlying health condition that could require medical treatment.

Fennel seeds are known to have several health benefits.

Some research suggests they may help to prevent or get rid of occasional gas. However, it’s important to note that few human studies have examined the effects of fennel on gas, bloating, and digestion.

Speak with a healthcare professional if you experience chronic gassiness. It may be a symptom of a digestive problem or disease. You may need medical treatment.