Dangers and side effects of wheatgrass powder & juice.

Consuming high amounts of wheatgrass powder or juice may cause side effects, such as nausea, headaches, diarrhea. discomfort, gas, and bloating. Although wheatgrass has many health benefits and a great nutritional value, some people better avoid excess consumption.

What is in wheatgrass?

Wheatgrass is the young grass of the wheat plant. In most cases, it is harvested on day 7, after sprouting. It’s really easy to grown wheatgrass at home. You’ll harvest the wheatgrass after a week.

We can consume wheatgrass in two ways. In powder or juice.

Nutritional value of wheatgrass

According to a 2015 study, published in the Journal of Pharmacy and Bioallied Sciences, wheatgrass is high in minerals. It contains a significant amount of iron, phosphorus, magnesium, manganese, copper, calcium, and zinc.

Wheatgrass powder is particularly rich in vitamin K (1,075 mcg per 100g), iron (12.5 mg), and calcium (300 mg).

Moreover, it has a great amount of chlorophyll, vitamin A, vitamin C, vitamin E, and bioflavonoids.

In addition, wheatgrass contains 17 amino acids, of which eight are essential. Just a tablespoon of wheatgrass has 1 g of protein!

Why is wheatgrass good for you?

Wheatgrass has remarkable therapeutic potentials. In fact, consumption of wheatgrass has been linked to beneficial effects on cancer, ulcerative colitis, rheumatoid arthritis, and bronchial disorders.

Dangers & side effects of consuming wheatgrass powder

Although wheatgrass consumption is considered pretty safe, there are some side effects and dangers that you should be aware of.


There are some cases that people experienced discomfort, after consuming wheatgrass. In most cases, people reported symptoms such as:

  • nausea,
  • headaches, or
  • diarrhea.

Most symptoms go away after decreasing the wheatgrass dose.

Vitamin K & medication

Also, wheatgrass is particularly high in vitamin K. It has 1,075 mcg of vitamin K per 100g. A tablespoon of wheatgrass powder contains 86 mcg of vitamin K. That’s almost the 100% of the Daily Value (DV).

Certainly, vitamin K has many great health benefits on bone mineral density, osteoporosis, cancer, insulin sensitivity, and heart diseases.

According to the American National Institutes of Health, we need about 90-120 mcg of vitamin K per day.

So, only a tablespoon of wheatgrass powder is enough to meet the recommended daily intake of vitamin K.

Although healthy people can consume high amounts of vitamin K without experiencing any side effects, people who take certain drugs, like anticoagulants or antibiotics, shouldn’t get extremely high doses of vitamin K.

Broccoli is another food particularly rich in vitamin K. A cup provides the recommended daily intake of vitamin K.

Always consult your physician before changing your diet or taking dietary supplements.

High amounts of fiber may cause discomfort

Actually, wheatgrass powder has an extremely high amount of fiber. It’s 50% fiber. A tablespoon of wheatgrass powder has 4 grams of fiber. That’s 14% of the DV.

Although dietary fiber has many health benefits, a huge amount of fiber in just one meal may cause discomfort to many people. A few side effects, such as excessive flatulence, bloating, abdominal cramps, or diarrhea can occur(1).

A high fiber diet is safe. In fact, there hasn’t been established a maximum safe dose for fiber. However, better increase your daily fiber intake gradually. Avoiding overconsumption of fiber-rich foods, such as wheatgrass, and beans (e.g. lentils) could protect us from stomach discomfort and other side effects.

Side effects of wheatgrass juice

Commercial wheatgrass juices are mostly safe.

On the other hand, if you grow wheatgrass at home, you have to be very cautious. The room must have good air circulation and low humidity. Otherwise, mold is going to grow in the wheatgrass trays.


  1. Position of the Academy of Nutrition and Dietetics: Health Implications of Dietary Fiber