History of Chlorella and the Side Effects

If you don’t know what chlorella is, it is a genus of a single cell green algae belonging in the division Chlorophyta. It is spherical in shape, about 2 to 10 micrometer in diameter, and is without flagella. Without further ado, let’s “talk” about the history of chlorella, the side effects of chlorella, precautions, other things that you should know before taking it, the suitable dosage and more.

History of Chlorella
Following global fears of an uncontrollable human population boom during the late 1940s and the early 1950s, Chlorella was seen as a new and promising primary food source and as a possible solution to the then-current world hunger crisis. Many people during this time thought hunger would be an overwhelming problem and saw Chlorella as a way to end this crisis by providing large amounts of high-quality food for a relatively low cost.

Many institutions began to research the algae, including the Carnegie Institution, the Rockefeller Foundation, the NIH, UC Berkeley, the Atomic Energy Commission, and Stanford University. Following World War II, many Europeans were starving, and many Malthusians attributed this not only to the war, but also to the inability of the world to produce enough food to support the increasing population. According to a 1946 FAO report, the world would need to produce 25 to 35% more food in 1960 than in 1939 to keep up with the increasing population, while health improvements would require a 90 to 100% increase. Because meat was costly and energy-intensive to produce, protein shortages were also an issue. Increasing cultivated area alone would go only so far in providing adequate nutrition to the population. The USDA calculated that, to feed the U.S. population by 1975, it would have to add 200 million acres (800,000 km²) of land, but only 45 million were available. One way to combat national food shortages was to increase the land available for farmers, yet the American frontier and farm land had long since been extinguished in trade for expansion and urban life. Hopes rested solely on new agricultural techniques and technologies. Because of these circumstances, an alternative solution was needed.

To cope with the upcoming post-war population boom in the United States and elsewhere, researchers decided to tap into the unexploited sea resources. Initial testing by the Stanford Research Institute showed Chlorella (when growing in warm, sunny, shallow conditions) could convert 20% of solar energy into a plant that, when dried, contains 50% protein.[3] In addition, Chlorella contains fat and vitamins. The plant’s photosynthetic efficiency allows it to yield more protein per unit area than any plant—one scientist predicted 10,000 tons of protein a year could be produced with just 20 workers staffing a one-thousand-acre (4-square kilometer) Chlorella farm. The pilot research performed at Stanford and elsewhere led to immense press from journalists and newspapers, yet did not lead to large-scale algae production. Chlorella seemed like a viable option because of the technological advances in agriculture at the time and the widespread acclaim it got from experts and scientists who studied it. Algae researchers had even hoped to add a neutralized Chlorella powder to conventional food products, as a way to fortify them with vitamins and minerals.

When the preliminary laboratory results were published, the scientific community at first backed the possibilities of Chlorella. Science News Letter praised the optimistic results in an article entitled “Algae to Feed the Starving”. John Burlew, the editor of the Carnegie Institution of Washington book Algal Culture-from Laboratory to Pilot Plant, stated, “the algae culture may fill a very real need,” which Science News Letter turned into “future populations of the world will be kept from starving by the production of improved or educated algae related to the green scum on ponds.” The cover of the magazine also featured Arthur D. Little’s Cambridge laboratory, which was a supposed future food factory. A few years later, the magazine published an article entitled “Tomorrow’s Dinner”, which stated, “There is no doubt in the mind of scientists that the farms of the future will actually be factories.” Science Digest also reported, “common pond scum would soon become the world’s most important agricultural crop.” However, in the decades since those claims were made, algae has not been cultivated on that large of scale.


Side effects
Side effects generally occurred within the first few days of adding these supplements to their diet. These side effects included:
• Nausea
• Bloating
• Diarrhea
• Green Colored Stool
• Upset Stomach
• Sensitivity to Sunlight
• Headaches
• Muscle Pain

The above side effects usually occur when a person first begins using chlorella as a supplement and generally diminish as the body becomes adjusted. There are no documented reports of spirulina or chlorella negatively interacting with other foods or medications.

One of the great benefits of Chlorella is that it boosts the immune system, but if you have a condition such as multiple sclerosis, rheumatoid arthritis, or lupus, chlorella is not a supplement for you. These conditions are auto-immune diseases and chlorella could potentially worsen your condition.

As with any supplement, consult your physician if you are pregnant or breast-feeding. Even though our lab testing results show mercury levels are non-detectable, chlorella can have a high content of mercury, and it isn’t advised for women who are pregnant or breast-feeding.

In a very few cases, consumers have reported an allergic reaction to chlorella. The symptoms included breathing problems, chest tightness, hives, itching and/or a rash. These symptoms are considered major side effects and you should consult a physician immediately. If you are currently taking blood thinners, namely Coumadin, or its generic Warfarin, you should not take chlorella. Chlorella may have high levels of Vitamin K ,which when combined with a blood thinner, could affect blood clotting.

Again, if you have any doubts or questions, it is wise to consult your physician.
Ensure that the supplement you are buying is from a reputable and qualified supplier, because chlorella grown in contaminated water can concentrate toxins. For this reason, Perfect Aquatic Greens contains chlorella that is grown in the exceptionally clean & natural environment of the Hainan Island.


There have not been any studies conducted in humans to determine whether sun chlorella causes negative side effects–or what, if any, effects may be associated with prolonged use.
The ACS cautions not to depend on chlorella to replace traditional medical treatments for serious health conditions such as cancer.

Take only the recommended dosage listed on the label. Be sure to tell your doctor if you have any existing medical conditions, such as high blood pressure or heart or blood vessel disease. Don’t take sun chlorella if you are pregnant or breast feeding.
Other things you should know

According to Michelle Bosmier, because of the toxic load the average person carries, sometimes when people start a regime of chlorella they think they are experiencing side-effects. In reality, they are experiencing the effects of detoxification. The cleansing of toxins from the body may give you gas, nausea, stomach cramps, diarrhea, etc. For this reason, its good to start taking chlorella on a weekend, when you can stay close to home. If the side-effects of detoxing are too much for you, ease up on your consumption, adding it in slowly. The symptoms will pass in a couple of days. Chlorella has a high amount of vitamin K, so it could interfere with blood thinning medications. It also contains iodine, so if you are allergic, avoid it.

Chlorella is inexpensive partially because it is one of the fastest growing plants on Earth. It is the most potent source of pure chlorophyll available. Chlorophyll is identical to human blood except for the center element – blood’s is iron; chlorophyll’s is magnesium. For this reason it is uniquely wonderful for our health. It is a good addition to most diets and disaster kits. It is readily available well, so stock up!


The appropriate dose of chlorella depends on several factors such as the user’s age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for chlorella. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.


Chlorella comes in many forms, including capsule, tablet, softgel, powder, and liquid. It is found as a supplement alone or in a combination with other green food extracts such as wheat grass, barley grass , and spirulina (a nutritionally rich microorganism). Capsules and tablets are available in doses of 200–500 milligrams (mg). There is no standard dosage but some herbalists recommend 3 grams (g) per day. The average cost of a bottle of 100 capsules (containing approximately 125 mg each) ranges from $9 to $15.


Persons taking the blood-thinning drug known as Coumadin (generic warfarin) are advised to completely avoid chlorella, or use caution and follow the advise of their healthcare professional because some chlorella supplements contain high amounts of vitamin K that may affect the inhibition of blood clots.