Spirulina vs Chlorella: What Is Actually Different?

Put a spoonful of spirulina beside a spoonful of chlorella and you might struggle to tell them apart. Both are green powders often found on the same superfood shelf. But they're not the same ingredient.

Spirulina and chlorella are different organisms. Spirulina, usually produced from Arthrospira, is a cyanobacterium commonly called blue-green algae. Chlorella is a true, single-celled green alga. Spirulina is especially known for its protein-rich composition and phycocyanin pigment. Chlorella has a different chlorophyll profile and a relatively tough cell wall that is often broken down during processing.

If spirulina catches your interest as you read, you can explore our spirulina collection at Healthy, including straightforward powders and swallowable options.

Same green appearance, completely different organisms

Although it's commonly called blue-green algae, spirulina belongs to the cyanobacteria, a group of photosynthetic bacteria. Commercial spirulina is usually associated with Arthrospira, a name you'll still find on ingredient labels and scientific papers. You may also see Limnospira used in newer classifications.

Under a microscope, these organisms form long, thread-like filaments. Chlorella consists of individual green algal cells, each with a nucleus containing its genetic material. Spirulina, like other bacteria, has no membrane-bound nucleus.

Both use photosynthesis and can become green powders, but their cells are built differently.

The colour tells a more interesting story than you might expect

Spirulina contains chlorophyll and carotenoids, but one distinctive compound is phycocyanin. This blue pigment-protein complex is a key reason spirulina looks different from many other green ingredients.

Phycocyanin has attracted interest in antioxidant research. That doesn't mean a finished powder is proven to deliver a medical result.

Chlorella has its own colourful chemistry. It contains chlorophyll a and b, which help give it a strong green appearance, along with carotenoids. Spirulina also contains chlorophyll.

We like whole spirulina because it brings that characteristic blue-green pigment profile together in a clearly recognisable ingredient. You don't need to start with a specialist blue extract to explore what makes spirulina distinctive.

Why chlorella products often mention cracked cells

Another difference is invisible: the cell wall.

Chlorella has a comparatively rigid cell wall. That makes it useful to process the dried ingredient in a way that disrupts the wall, helping make the nutrients inside more accessible during digestion. You might see this described as cracked-cell chlorella or broken-cell chlorella.

Our Matakana Superfoods Organic Chlorella Powder is one example. It's a certified organic, single-ingredient chlorella powder made with cracked-cell processing. That tells you how it's been prepared.

Spirulina has a different cell-wall structure and generally doesn't need the same cracked-cell step. That makes its production story simpler in this respect. Cracking cells doesn't guarantee complete absorption or make uncracked products automatically unsafe.

What actually changes in the nutrients?

Both greens contain protein, amino acids, minerals and naturally occurring pigments. The amounts depend on the species, growing conditions and processing, so two products with similar names won't necessarily have identical nutrition panels.

Spirulina is particularly interesting for its high protein proportion by dry weight. Research comparisons often find it has a higher percentage of protein than chlorella, alongside its distinctive phycocyanin. Chlorella also supplies protein and has a chlorophyll-rich composition with its own mix of carotenoids and other compounds.

A figure per 100g of powder isn't what you get from a small serving. A 2.5g scoop of algae isn't a replacement for beans, eggs, tofu or other substantial protein foods. Think of these powders as concentrated additions to a varied diet, not substitutes for meals or vegetables.

And what about vitamin B12? This deserves special care, especially if you eat a vegan or vegetarian diet. Spirulina can contain compounds that look like B12 in some tests, but much of this may be inactive pseudo-vitamin B12, which your body cannot use in the same way as active B12.

In a 2022 study of 57 commercial algae supplements, pseudo-B12 predominated in the spirulina products, while active B12 was more common in chlorella products. Chlorella amounts still varied considerably. Neither ingredient should be your sole B12 plan. Choose a reliable source such as appropriately fortified foods or a suitable B12 supplement.

At Healthy, these two greens appear in three different ways

You can see the difference in our actual products, starting with a simple, single-ingredient powder.

Our Matakana Superfoods Organic Spirulina Powder is a lovely place to begin if spirulina is what you came for. It's a 100g pack of certified organic spirulina powder with one ingredient, no added colourings or preservatives, and a non-GM product statement. The label gives a 2.5g serving and suggests adding it to water, juice or a smoothie. We appreciate that simplicity: you know exactly which green ingredient you're choosing.

Beside it in the range, Matakana Superfoods Organic Chlorella Powder offers a different 100g, single-ingredient green. Its cracked-cell processing makes sense once you understand chlorella's tougher outer wall. It isn't spirulina in different packaging; it's a separate organism with its own characteristics.

Then there's Matakana Superfoods Super Greens Powder. This 200g blend contains both organic spirulina and organic cracked-cell chlorella, as well as organic kale, wakame, wheat leaf, barley leaf and broccoli sprout powders. Made in New Zealand from local and imported ingredients, it shows how both greens can sit together in one formula.

If you're mainly excited by spirulina's protein-rich composition and phycocyanin, we think the pure Matakana powder is a particularly appealing first product to explore.

If spirulina is the ingredient that interests you, here's where to look

Once you've decided it's spirulina you want to explore, our range of spirulina supplements in NZ brings the available formats together. You can check the ingredients and serving directions for each product without having to guess whether it contains chlorella as well.

For another powder option, we stock Lifestream Spirulina Bioactive Powder, made with Arthrospira platensis and listed in 100g and 200g sizes. Its adult label serving is 3g. We also stock Lifestream Spirulina Bioactive Tablets, a 200-tablet pack containing spirulina powder plus silica; its label lists six tablets as a 3g adult serving.

Each has its own ingredient details, so check the label.

A few things worth knowing before choosing either green

With any concentrated algae ingredient, quality matters. Cultivation, handling and manufacturing controls help manage possible contaminants. Some blue-green algae products have raised concerns about toxins called microcystins, although that doesn't mean a particular Healthy product is contaminated. Reputable sourcing and appropriate testing are sensible things to look for.

Follow the directions on your chosen product rather than assuming all algae powders share the same serving size. Some people may notice digestive discomfort or individual sensitivities when trying a new supplement.

If you take warfarin, speak with your pharmacist or treating clinician before adding a new green supplement. Changes in vitamin K intake can matter, and our Matakana Super Greens blend specifically contains naturally occurring vitamin K. Check with a health professional first if you're pregnant, breastfeeding, taking relevant medicines or managing a significant medical condition.

Look at the ingredients, choose a format you like and keep your diet varied.

Common questions

What is the biggest difference between spirulina and chlorella?

Spirulina is a cyanobacterium, commonly called blue-green algae, while chlorella is a true single-celled green alga. Their cells are built differently. Spirulina is notable for phycocyanin, and chlorella contains chlorophyll a and b and a tougher cell wall that's often disrupted during processing.

Is spirulina better than chlorella?

Neither is better for everyone. They have different compounds and come in different finished formulas. Spirulina is well worth exploring if you're interested in its naturally protein-rich composition and characteristic phycocyanin. The right product depends on the full ingredient list and what appeals to you.

Which has more protein, spirulina or chlorella?

Spirulina often has a higher protein percentage when the two are compared by dry weight, although amounts vary by species and product. Chlorella also contains protein. Because typical supplement servings are small, neither should replace the main protein foods in your diet.

Why is chlorella called cracked-cell chlorella?

Chlorella has a relatively tough cell wall. Cracked-cell processing disrupts this outer layer so nutrients inside can become more accessible during digestion. It describes a production step, not a different species, and it doesn't guarantee complete absorption of every nutrient.

Does spirulina contain vitamin B12?

Spirulina can contain B12-related compounds, but much of the amount reported in testing may be biologically inactive pseudo-vitamin B12. That makes it an unreliable way to meet your B12 needs. Use a dependable source of active B12, particularly if you eat a plant-based diet.

Can you take spirulina and chlorella together?

Some greens blends contain both. For example, our Matakana Super Greens Powder includes spirulina and cracked-cell chlorella among seven green ingredients. Check the complete formulation and directions to see whether it suits you. There's no need to combine extra products just because both ingredients are available.

Is blue spirulina the same as chlorella?

No. Blue spirulina generally refers to a phycocyanin-rich preparation derived from spirulina. Chlorella is a completely different green alga. Blue spirulina, whole spirulina and chlorella may all look interesting on a supplement shelf, but they aren't interchangeable ingredients.

Explore spirulina at Healthy

Spirulina and chlorella can look almost identical in a scoop, yet their biology, pigments and processing are genuinely different. We think spirulina is a wonderful ingredient to get to know for its protein-rich composition, blue-green phycocyanin and straightforward whole-powder options.

At Healthy, we stock spirulina products from Matakana Superfoods and Lifestream, including powder and tablet choices. Explore the current range, compare ingredients and follow the label that suits the product you choose.

References

• Rzeski and Rzeska, 2026. Chlorella and Arthrospira (Spirulina): molecular mechanisms and clinical evidence.
• Frontiers in Nutrition, 2022. Algae Supplementation for Exercise Performance.
• Journal of Applied Phycology. Algae as nutritional and functional food sources.
• van den Oever and Mayer, 2022. Biologically active or pseudo-vitamin B12 in algae supplements?
• NIH Office of Dietary Supplements. Vitamin B12 fact sheet.
• US Food and Drug Administration. Blue-Green Algae Products and Microcystins.
• Medsafe NZ, 2022. Warfarin: eat, drink and be wary.