Chlorella Nutrition Facts

The nutritional panel on a chlorella supplement tells you something genuinely unusual: a single-celled freshwater organism that is 50 to 60% protein by dry weight, with more chlorophyll per gram than any other food you can buy. Those numbers are real.

What the panel cannot tell you is how much of that nutrition you absorb at a realistic supplement dose, which figures shift depending on the species and growing conditions, and where the impressive percentages become less impressive arithmetic.

If you are standing in a health shop turning a tub of chlorella powder over to read the back, the numbers you see there deserve some context. We source and sell chlorella ourselves, so we have a direct interest in those numbers being understood honestly rather than inflated.

Chlorella Nutrition Facts at a Glance

Chlorella Calories, Protein, and Serving Size

At a standard supplement dose of 3 to 5 grams, chlorella contributes roughly 12 to 20 calories. Most of that comes from protein and a small amount of fat. In calorie terms, it is negligible. The interest lies elsewhere.

Protein Density vs Protein Reality at Chlorella Doses

Chlorella is roughly 50 to 60% protein by dry weight, with all nine essential amino acids present (Becker, 2007). That protein density is remarkable. It exceeds beef, eggs, and most legumes on a gram-for-gram basis. The figure appears on marketing materials constantly, and it is not wrong.

But you are not eating 100 grams of chlorella. At 3 to 5 grams per day, you are getting 1.5 to 3 grams of protein. A single boiled egg delivers roughly 6 grams. A tablespoon of porridge oats gives you about 2 grams.

We include the protein content on our chlorella labels because it is genuinely present. But if someone tells you chlorella is a protein supplement, they are confusing concentration with dose.

Amino Acid Profile in Chlorella

The amino acid profile is complete, meaning all nine essential amino acids are present. The distribution is reasonable but not perfectly balanced for human requirements. Methionine and cysteine tend to be the limiting amino acids in chlorella, as they are in most microalgae (Becker, 2007). At supplement doses this barely matters, because you are getting your amino acids from your meals, not from a 3-gram scoop of powder.

Chlorophyll Content in Chlorella

Open a bag of chlorella powder and the colour tells you something immediately. The green is so concentrated it stains your fingers, your spoon, and anything else it touches. That intensity is not a dye. It is chlorophyll, and chlorella contains more of it per gram than spinach, kale, parsley, or any other commonly cited source.

Published analyses put chlorella's chlorophyll content at roughly 1 to 4% of dry weight, depending on species and growing conditions (Panahi et al., 2016). That may sound modest as a percentage, but in absolute terms per gram it is several times higher than any terrestrial green vegetable. If you are specifically seeking dietary chlorophyll, no food delivers it more efficiently.

Chlorophyll has documented antioxidant properties in laboratory systems. It does not, however, have an EFSA-authorised health claim. You will find products suggesting chlorophyll "detoxifies your blood" or "oxygenates your cells." Those claims are not permitted under EU food regulation, and we do not make them. The compound is interesting. The marketing attached to it runs ahead of the evidence.

Vitamins in Chlorella Supplements

Chlorella contains B-group vitamins including B1 (thiamine), B2 (riboflavin), B6, and folate. At a 3 to 5 gram serving, the contribution to your daily requirements is real but partial. You would not rely on chlorella to hit your B-vitamin targets on its own.

The B12 Problem in Chlorella

B12 is the vitamin that causes the most confusion in the chlorella market, and if you are vegan, this matters to you directly. Chlorella is frequently marketed as a natural source of B12. Some nutritional panels show apparently meaningful amounts. The problem is what those panels are actually measuring.

Standard microbiological assays detect both true cobalamin (the form your body uses) and pseudocobalamin (a corrinoid analogue your body handles poorly). Some chlorella strains, particularly Chlorella vulgaris, produce predominantly pseudocobalamin (Watanabe et al., 2013). Not every manufacturer distinguishes between the two on the label, and not every manufacturer knows which form their product contains.

If you are vegan and relying on chlorella for B12, we would not recommend it as your sole source. A dedicated B12 supplement costs less than a pound a month and eliminates the guesswork. Your GP can check your B12 status with a blood test. We covered this in detail in our chlorella benefits article.

Chlorella Growth Factor: Nutrition or Marketing?

Some chlorella products highlight "Chlorella Growth Factor" or CGF on their labels, presenting it as a unique nutritional advantage. CGF is a nucleotide-peptide complex found in the nucleus of chlorella cells. It is real in the sense that it exists, and it is involved in the organism's rapid cell division.

Whether CGF provides any measurable nutritional benefit to humans at supplement doses is a different question, and published clinical evidence for specific CGF health claims is extremely thin. If a product charges a premium for high-CGF chlorella, you should ask what specifically that premium is buying you in terms of evidence.

Minerals in Chlorella

Chlorella provides iron, magnesium, zinc, and phosphorus. The concentrations vary with species, growing medium, and cultivation conditions. A chlorella grown in iron-enriched media will have a different mineral profile from the same species grown in a standard medium.

Iron in Chlorella: Useful but Non-Haem

The iron in chlorella is non-haem iron, the plant-derived form that your body absorbs less efficiently than the haem iron in meat. At a 3 to 5 gram dose, the iron contribution is meaningful enough to support your overall intake, but it is not a replacement for medical iron supplementation if you have been diagnosed with deficiency.

A practical step that costs you nothing: take your chlorella with a source of vitamin C. A glass of orange juice, a kiwi fruit, or some sliced bell pepper alongside your dose significantly enhances non-haem iron absorption. If you are plant-based, this habit is worth building regardless of whether you take chlorella.

Other Minerals at Supplement Doses

Magnesium and zinc are present but contribute a small fraction of your daily requirement at typical doses. Chlorella is nutritionally broad, which is part of its appeal, but treating any single-organism supplement as a mineral replacement misreads what supplement doses can deliver.

Does Chlorella Contain Omega-3?

Yes, but not the type you are probably hoping for. Chlorella's fatty acid profile includes ALA (alpha-linolenic acid), a short-chain omega-3. It does not contain EPA or DHA, the long-chain omega-3 fatty acids that carry EFSA-authorised health claims for heart function.

Your body can convert ALA to EPA and then to DHA, but the conversion rates are poor. Published estimates suggest roughly 5 to 10% of ALA converts to EPA, and less than 1% reaches DHA (Brenna et al., 2009). At chlorella supplement doses, the amount of ALA you are starting with is already small. The arithmetic does not work in your favour.

If you need long-chain omega-3 from a non-fish source, marine phytoplankton from Nannochloropsis gaditana provides EPA directly. Algae oil from Schizochytrium provides DHA. Chlorella does neither. Any product implying otherwise is misstating what this species produces.

Chlorella vs Spirulina Nutrition

These two sit next to each other on every health shop shelf, and the question you are likely asking is whether one is better than the other. The honest answer is that they are nutritionally different organisms solving different problems.

Spirulina is 55 to 70% protein with unique phycocyanin (the blue pigment) but very little chlorophyll and no meaningful omega-3 of any type. Chlorella is 50 to 60% protein, leads on chlorophyll by a wide margin, contains non-haem iron, and has a complete cell wall that affects how you digest it.

For protein density: spirulina wins. For chlorophyll: chlorella wins, and it is not close. For omega-3: neither is useful. You would need Nannochloropsis for EPA or algae oil for DHA. For iron: chlorella provides more, though both are non-haem.

We sell both chlorella and phytoplankton products, and we are asked this comparison question constantly. The answer we give is always the same: which nutrient gap are you actually trying to fill? "Which is better" is not a question that has a fixed answer when the nutrient profiles are this different.

How to Read a Chlorella Supplement Label

A nutritional information panel on a chlorella product tells you what is in a representative batch. It does not tell you everything you need to make a good decision. Three things to look for beyond the numbers.

Species name. The label should say Chlorella vulgaris or Chlorella pyrenoidosa. "Chlorella" without a species name is a genus label, not a specific ingredient. Different species have different nutritional profiles, and the B12 question in particular depends on which species you are taking.

Cell-wall processing. Chlorella has a tough cellulose cell wall that human digestive enzymes cannot break down efficiently. If the product does not mention broken cell wall, cracked cell wall, or fermentation, the impressive numbers on the panel may not translate to what you actually absorb. We use fermented (broken-cell-wall) chlorella in our products because the bioavailability difference matters more than the panel numbers.

Serving size vs daily dose. Some labels list nutrients per tablet or per gram, others per "suggested daily dose" of several grams. Compare like with like. A product that looks nutrient-dense per gram may have a suggested dose of 1 gram, leaving you with a fraction of what you expected.

FAQs About Chlorella Nutrition

How much protein do you get from a chlorella supplement?

At a typical dose of 3 to 5 grams, you are getting roughly 1.5 to 3 grams of protein. That is a useful amino acid contribution alongside your meals but it is not a protein supplement in any practical sense. If protein is your primary goal, whole food sources or a dedicated protein powder will serve you far more effectively.

Is chlorella a reliable source of B12 for vegans?

We would not recommend it as your sole B12 source. Some chlorella strains produce predominantly pseudocobalamin rather than the true cobalamin your body needs. A dedicated B12 supplement is cheaper and eliminates the uncertainty. Ask your GP to check your B12 levels if you are unsure.

Does breaking the cell wall actually matter?

Yes. Chlorella's cellulose cell wall is resistant to human digestive enzymes. Without mechanical cracking, fermentation, or another processing step, a significant proportion of the nutrients inside the cell may pass through your digestive system unabsorbed. The numbers on the label assume you can access what is inside.

How many calories are in a chlorella supplement?

Roughly 12 to 20 calories at a 3 to 5 gram dose. The calorie contribution is negligible. You are not taking chlorella for energy. You are taking it for the micronutrient density packed into that small serving.

Can chlorella replace a multivitamin?

No. Chlorella is nutritionally broad but it does not cover every micronutrient at clinically meaningful amounts. It provides no meaningful vitamin D, no long-chain omega-3, and its B12 content is unreliable. It contributes to your overall nutrient intake rather than replacing targeted supplementation where you have specific gaps.

How does chlorella compare to spirulina for iron?

Chlorella generally provides more iron per gram than spirulina. Both supply non-haem iron, which is absorbed less efficiently than the haem iron in meat. Pairing either with vitamin C improves absorption. If your GP has identified iron deficiency, a dedicated iron supplement will be more effective than either microalga at typical supplement doses.

This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Consult your GP before starting any supplement.

Methodology and Disclosure

Phytality manufactures and sells fermented chlorella supplements. We have a direct commercial interest in this ingredient. All nutritional figures are drawn from published peer-reviewed literature cited above. No EFSA-authorised health claims are made for chlorella or chlorophyll in this article, and where claims are absent we have stated so explicitly. Comparisons with spirulina reflect established compositional differences documented in published reviews. The Phytality Perspective box reflects our product specifications only.

Last reviewed: March 2026. Next review due: March 2027.