Background

Chlorella (Chlorella pyrenoidosa) is a type of algae that grows in fresh water. It's sometimes called seaweed. It's used for nutrition and as medicine.

Chlorella is a good source of protein, fats, carbohydrates, fiber, chlorophyll, vitamins, and minerals. Most of the chlorella that is available in the U.S. is grown in Japan or Taiwan. It's made into tablets and liquid extracts.

Chlorella is used to prevent low levels of iron during pregnancy. It is also used for depression, menstrual cramps, fibromyalgia, high cholesterol, and other conditions, but there is no good scientific evidence to support many of these uses.

Safety Safety definitions

When taken by mouth: Chlorella is likely safe when used for 2-3 months. The most common side effects include diarrhea, nausea, gas, green stools, and stomach cramping. Chlorella can also make the skin extra sensitive to the sun. Wear sunblock outside, especially if you are light-skinned.

When applied to the skin: There isn't enough reliable information to know if chlorella is safe or what the side effects might be.

Special Precautions & Warnings:

Pregnancy: Chlorella is possibly safe when taken by mouth for up to 28 weeks, starting during the second trimester of pregnancy.

Breast-feeding: There isn't enough reliable information to know if chlorella is safe to use when breast-feeding. Stay on the safe side and avoid use.

Allergy to molds: Chlorella might cause an allergic reaction in people who are also allergic to molds.

Weak immune system (immunodeficiency): Chlorella might cause "bad" bacteria to take over in the intestine of people who have a weak immune system. Use caution if you have a weakened immune system.

Effectiveness

Dosing & administration

Chlorella has most often been used by adults in doses of 3-10 grams by mouth daily for 2-3 months. Speak with a healthcare provider to find out what dose might be best for a specific condition.

Keep in mind that chlorella products can vary depending on the way the chlorella was cultivated, harvested, and processed. Dried chlorella can contain from 7% to 88% protein, 6% to 38% carbohydrates, and 7% to 75% fat.

Interactions with pharmaceuticals

Medications that increase sensitivity to sunlight (Photosensitizing drugs)

Interaction Rating=Moderate Be cautious with this combination.

Some medications might make the skin more sensitive to sunlight. Chlorella might also make the skin more sensitive to sunlight. Using these products together might increase the risk of sunburn, blistering, or rashes when the skin is exposed to sunlight. Be sure to wear sunblock and protective clothing when spending time in the sun.

Warfarin (Coumadin)

Interaction Rating=Moderate Be cautious with this combination.

Chlorella contains large amounts of vitamin K. Vitamin K is used by the body to help the blood clot. Warfarin is used to slow blood clotting. Chlorella might decrease the effects of warfarin. Be sure to have your blood checked regularly. The dose of your warfarin might need to be changed.

Interactions with herbs & supplements

Herbs that might increase sensitivity to sunlight: Chlorella might make the skin more sensitive to sunlight. Using it with other products that also make the skin more sensitive to the sun might increase the risk for sunburn and other side effects. Examples of supplements with this effect include bishop's weed, chlorophyll, khella, and St. John's wort.

Interactions with foods

There are no known interactions with foods.