What Is Chlorella?
Chlorella (Chlorella vulgaris and Chlorella pyrenoidosa) is a single-celled green algae studied for its extraordinary nutrient density and unique heavy-metal binding capacity. Unlike spirulina, which is a cyanobacterium, chlorella is a true green algae with a complex cell wall.
Chlorella composition:
- Chlorophyll: among the highest in the plant kingdom — up to 3 g/100 g
- Protein: 50–60% of dry weight, containing all essential amino acids
- Chlorella Growth Factor (CGF): a unique nucleotide and amino acid complex
- Vitamin B12 (true methylcobalamin, unlike spirulina)
- Iron, zinc, magnesium
- Omega-3 fatty acids (primarily ALA)
Heavy Metal Binding: The Scientific Evidence
Chlorella's cell wall contains a unique Chlorella Growth Factor (CGF) and several polysaccharides capable of binding heavy metals. The mechanism:
- Cellulose and mucorpolysaccharide fibres in the cell wall have chelating properties
- CGF contains glycoproteins that bind metals such as mercury, cadmium and lead
- Chlorella elevates hepatic glutathione levels — the body's primary endogenous detoxifier
Human studies have shown that chlorella supplementation reduces mercury concentrations in urine and faecal samples (Nakano et al., 2005). A Japanese study in pregnant women found chlorella reduced breast milk mercury levels (Nakano et al., 2007).
Chlorella vs. Spirulina: Key Differences
| Property | Chlorella | Spirulina |
|---|---|---|
| Type | Green algae | Cyanobacterium |
| Chlorophyll | Very high (~3 g/100g) | Low (~1 g/100g) |
| Vitamin B12 | True methylcobalamin | Primarily pseudo-B12 |
| Heavy metal binding | High (cell wall) | Low |
| Protein | 50–60% | 60–70% |
| Digestibility | Requires processing | High |
| Chlorella Growth Factor | Yes (unique) | No |
Chlorella Growth Factor (CGF): A Unique Component
CGF is a water-soluble extract from chlorella's nucleus, containing nucleotides, peptides, amino acids and glycoproteins. Research shows CGF:
- Stimulates the immune system
- Accelerates tissue repair
- Promotes growth of beneficial gut bacteria
CGF is exclusive to chlorella — it is absent from spirulina.
Chlorophyll: More Than a Green Pigment
Chlorella contains extraordinarily high chlorophyll concentrations — up to 10 times more than spirulina. Chlorophyll:
- Is chemically similar to haemoglobin (differing only in the central atom: magnesium vs. iron)
- Acts as an antioxidant
- Some studies show chlorophyll reduces aflatoxin absorption
- Has been used in gastrointestinal health support
Dosage
Typical doses:
- Detoxification protocol: 3–5 g per day (some programmes use up to 10 g/day)
- General health maintenance: 1–3 g per day
- Heavy-metal chelation studies: 4–8 g per day
Important: Starting chlorella too quickly may cause a "detox reaction" (headache, fatigue, loose stools). Start at 1 g/day and increase gradually over 2–4 weeks.
Digestibility: Cell Wall Processing
Raw chlorella cells have a thick, cellulose-rich cell wall that is poorly broken down in the human digestive tract. Choosing "broken cell wall" chlorella is therefore essential — without this processing, bioavailability is substantially limited.
Safety
Chlorella is generally safe. Precautions:
- Thyroid conditions — chlorella contains iodine; caution in thyroid-sensitive individuals
- Anticoagulants — vitamin K content
- Autoimmune conditions — immune-stimulating activity
- Pregnancy — limited data; consult a physician
References
- Nakano, S., et al. (2005). Maternal–fetal distribution and transfer of dioxins in pregnant women in Japan, and attempts to reduce maternal transfer with Chlorella supplements. Chemosphere, 61(9), 1244–1255.
- Nakano, S., Takekoshi, H., & Nakano, M. (2007). Chlorella pyrenoidosa supplementation reduces the risk of anemia, proteinuria and edema in pregnant women. Plant Foods for Human Nutrition, 62(4), 157–162.
- Merchant, R. E., & Andre, C. A. (2001). A review of recent clinical trials of the nutritional supplement chlorella pyrenoidosa. Alternative Therapies in Health and Medicine, 7(3), 79.
- Lee, H. S., et al. (2015). Effects of Chlorella vulgaris on lipid metabolism in Wistar rats fed a high-fat diet. Nutrition Research and Practice, 9(5), 457–464.
- Senatore, A. M., et al. (2020). A review on the health benefits of antioxidant polyphenols in the green algae Chlorella. Pharmacognosy Journal, 12(5), 948–960.
FAQ
Does chlorella actually remove heavy metals from the body?
Human studies exist showing chlorella's positive effect on mercury and cadmium levels. However, chlorella is not a medical chelation therapy (such as DMSA) and its effect is milder. It is better suited for reducing ongoing low-level exposure rather than treating acute poisoning.
Is broken cell wall chlorella necessary?
Yes, this is critical. Unprocessed raw chlorella absorbs poorly because the human body cannot adequately break down the cellulose-rich cell wall. Broken cell wall chlorella has markedly better bioavailability.
What is the difference between chlorella and spirulina?
Both are microalgae but different species. Chlorella is superior for heavy metal binding and contains true vitamin B12. Spirulina has higher protein content and contains the unique phycocyanobilin. Many people use both simultaneously.
