Agar Agar Side Effects

Though Agar agar is considered safe, it may cause side effects such as mild diarrhea and, theoretically, when ingested with insufficient fluid, esophageal or bowel obstruction. Allergy to agar is possible.


- Side effects may include gastrointestinal irritation, pain, and diarrhea when agar is given in powdered form in large doses.

- Phytobezoars, which are rarely occurring concentrations of fruit and vegetable fibers in the gastrointestinal tract, have been reported following ingestion of high-fiber foods such as agar.

- Agar products may delay stomach emptying time and reduce the absorption of some drugs, herbs, and supplements. It is advised that these agents and agar be taken at different times to minimize potential interactions.

- Agar may reduce body weight and body mass index (BMI).

- Agar may lower blood sugar levels. Caution is advised in patients with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugar. Blood glucose levels may need to be monitored by a qualified healthcare professional, including a pharmacist, and medication adjustments may be necessary.

- Agar may affect blood cholesterol levels. Use with caution in individuals with high levels of fats in the blood (hyperlipidemia) and those taking drugs, herbs, or supplements to treat this condition.

- Use with caution because agar and other fermentable fiber supplements enhanced tumor development in studies that chemically induced colon cancer in experimental animals.

- Use with caution in individuals taking laxatives, as use of agar with laxatives may have additive effects.

- Avoid in patients with bowel obstruction or swallowing difficulties, as agar use may worsen esophageal or bowel obstruction, particularly when taken with insufficient amounts of fluid.

- Avoid in pregnant or breastfeeding women due to a lack of available scientific evidence.

- Avoid in patients with an allergy/hypersensitivity to agar, its constituents, red seaweed, or related species.