Spirulina vs chlorella: what is the difference?
Short answer: Spirulina vs chlorella: the biggest difference is what they are. Spirulina is a blue-green cyanobacterium (Arthrospira platensis) from warm, salty lakes, chlorella is a green, single-celled freshwater alga with a sturdy cell wall. You buy spirulina as powder or tablets, chlorella from us as tablets. You can also take them together, in one tablet or from two jars, as long as you stick to the daily dose on the label.
Last updated: 5 November 2026 · Written by Florian Fermin
Spirulina and chlorella are often mentioned in the same breath. Both green, both algae, both sold as tablets. Yet they really are different organisms, with different points to watch.
In this article I put the differences side by side, explain when you would rather choose one or the other and how to take them together. Want to know more about one of the two first? Then read what is spirulina or what is chlorella.
What is the difference between spirulina and chlorella?
Spirulina is a cyanobacterium, chlorella a true green alga (Verbraucherzentrale Hamburg, 2025). Chlorella has a cellulose cell wall that you cannot digest when it is intact. That is why this cell wall is mechanically broken in most supplements (Bito et al., 2020). The main differences at a glance:
| Spirulina | Chlorella | |
|---|---|---|
| What is it | Blue-green microalga, biologically a cyanobacterium | Green, single-celled freshwater alga with a cellulose cell wall |
| Latin name | Arthrospira platensis (also Spirulina platensis) | Including Chlorella vulgaris and Chlorella pyrenoidosa |
| Where it grows | Warm, salty lakes, now grown in ponds | Fresh water, cultivated |
| Colour | Blue-green | Deep green, from chlorophyll |
| Vitamin B12 | Mostly pseudovitamin B12, not active in humans | Varies widely per product, partly in inactive form |
| Vitamin K | Not flagged in our sources | Contains vitamin K: take care with vitamin K antagonists |
| At GOYU | Powder and 500 mg tablets | 500 mg tablets |
| EU status | Not novel in food | Not novel in food |
About B12: in spirulina tablets, about 83% of the measured B12 turned out to be pseudovitamin B12 (Watanabe et al., 1999). In chlorella products, the measured B12 content ranged from less than 0.1 to 400 µg per 100 grams, and some contained inactive variants (Bito et al., 2020). So don't rely on either of them for B12.
Both algae are listed in the European Commission's Novel Food Catalogue as "not novel in food". They were already eaten in the EU before 1997 and may simply be used in foods and supplements (EU Novel Food Catalogue).
Which chlorella species is in our products?
That differs per product. According to the product page, Chlorella Tablets 500 mg Organic contain Chlorella pyrenoidosa. Spirulina Chlorella Tablets 500 mg Organic contain Chlorella vulgaris. The Chlorella & Spirulina Tablets Combo Deal consists of one jar of Chlorella Tablets and one jar of Spirulina Tablets.
The classification of chlorella species has changed in recent years. In the EU catalogue, Chlorella pyrenoidosa is now also listed as Auxenochlorella pyrenoidosa. For the legal status this makes no difference: all the species mentioned are "not novel" (European Commission, 2022).
Spirulina or chlorella: which is better?
Neither is better: they differ in form, taste and points to watch. Choose based on how you want to use it and whether one of the points below applies to you.
- You want powder in your smoothie: choose spirulina. We only sell chlorella as tablets.
- You take a vitamin K antagonist (such as warfarin or acenocoumarol): check first, especially with chlorella. In a Japanese case report, warfarin worked less well after someone started taking chlorella (Ohkawa et al., 1995).
- You have PKU: ANSES advises against spirulina for people with PKU (ANSES, 2017). Chlorella also contains phenylalanine (Bito et al., 2020). Check with your doctor or dietitian for both.
- You are allergic to algae: take neither.
- You want both: that is possible, see below.
These nutrition claims apply to our products: Spirulina is naturally high in protein**, Chlorella is naturally high in protein** and for the combination tablet Spirulina and chlorella are naturally high in protein**.
**Authorised health claim (Regulation (EU) No 432/2012) or nutrition claim (Regulation (EC) No 1924/2006).
Can you take spirulina and chlorella together?
Yes, you can take spirulina and chlorella together. There is no known reason why the combination would be a problem, but we did not find research that looks specifically at the combination. Stick to the daily dose per product and add up how much algae you get in total.
With us, you can do that in two ways:
| Product | What's in it | On the packaging | Per day (calculated) |
|---|---|---|---|
| Spirulina Chlorella Tablets 500 mg Organic | Per tablet 250 mg spirulina and 250 mg chlorella, 300 tablets | 3 tablets twice per day with water | 1.5 g spirulina and 1.5 g chlorella, 50 days |
| Chlorella & Spirulina Tablets Combo Deal | One jar of chlorella and one jar of spirulina tablets, each 500 mg per tablet | Of each, 3 tablets twice a day with water | 3 g spirulina and 3 g chlorella |
With the combination tablet you have one jar and take a smaller amount of both. With the combo deal you take the full daily dose of both, so 12 tablets per day. Don't combine the combination tablet with separate jars as well, unless your doctor agrees.
How much of each to take is covered in spirulina dosage and chlorella dosage.
Taking spirulina and chlorella together: how to do it
- Choose whether you want the combination tablet or two separate jars.
- Take the tablets with water, during or just after a meal.
- Spread them over two moments, for example at breakfast and at dinner.
- Do you use another product with algae, such as a greens mix? Count it in and stay within the daily dose.
- If you get stomach complaints or a skin rash, stop and talk to your GP.
What should you look for when buying?
With spirulina and chlorella you look for the same things: which species is inside, how many milligrams per tablet, whether each batch has been tested for heavy metals and (for spirulina) microcystins, and what else is in it. Algae can contain heavy metals such as cadmium and lead (Verbraucherzentrale Hamburg, 2025), and for spirulina ANSES recommends products with a clearly identified manufacturer and traceable origin (ANSES, 2017).
All our spirulina and chlorella tablets are organic, without artificial additives. You can request a certificate of analysis (CoA) via support@getgoyu.com. What the CoA of our spirulina shows, you can read in what is spirulina. What to look for in chlorella tablets is covered in chlorella tablets: what to look for.
Summary in 3 points
- Spirulina is a blue-green cyanobacterium, chlorella a green freshwater alga with a cell wall that is usually broken in supplements.
- Neither is better. With chlorella, watch out for vitamin K if you take blood thinners, and with spirulina for PKU and purity.
- Taking them together is possible: with the combination tablet (1.5 g of each per day) or with two jars (3 g of each per day), according to the label.
Frequently asked questions
Which is healthier: spirulina or chlorella?
There is no clear-cut answer: we did not find research that compares them properly. They mainly differ in species, form and points to watch. Choose what suits your use and any medication you take.
Can you take chlorella and spirulina at the same time?
Yes, you can take them at the same moment, for example with a meal. Stick to the daily dose of each product. If you take blood thinners or other medication, check with your pharmacist first.
How much spirulina and chlorella is in a combination tablet?
Our Spirulina Chlorella Tablets contain 250 mg spirulina and 250 mg chlorella (Chlorella vulgaris) per tablet. With 6 tablets a day, that is 1.5 grams of each.
Is chlorella the same as spirulina?
No. Chlorella is a green alga with a cell nucleus and a cellulose cell wall, spirulina is a cyanobacterium. They are often sold together, but they are different organisms.
Sources
- Verbraucherzentrale Hamburg. Algen essen: Auf den Jodgehalt achten, 4 February 2025. vzhh.de
- Bito T, Okumura E, Fujishima M, Watanabe F. Potential of Chlorella as a dietary supplement to promote human health. Nutrients. 2020;12(9):2524. doi:10.3390/nu12092524 (two authors work for a chlorella producer)
- Watanabe F, Katsura H, Takenaka S, et al. Pseudovitamin B12 is the predominant cobamide of an algal health food, spirulina tablets. J Agric Food Chem. 1999;47(11):4736-4741. doi:10.1021/jf990541b
- European Commission. Novel Food Catalogue, entries Arthrospira platensis, Chlorella vulgaris and Chlorella pyrenoidosa: not novel in food. food.ec.europa.eu
- European Commission. Novel food status consultation Chlorella sp., 2022. food.ec.europa.eu
- Ohkawa S, Yoneda Y, Ohsumi Y, Tabuchi M. Warfarin therapy and chlorella. Rinsho Shinkeigaku. 1995;35(7):806-807. PubMed 8777808
- ANSES. Compléments alimentaires à base de spiruline (opinion 2014-SA-0096), 30 November 2017. anses.fr
- Product pages and packaging texts of Spirulina Tablets, Chlorella Tablets, Spirulina Chlorella Tablets and the Chlorella & Spirulina Tablets Combo Deal, consulted 5 November 2026.
See all options on the pages buy spirulina and buy chlorella.
This article is for information only and is not medical advice. Food supplements are not a substitute for a varied and balanced diet and a healthy lifestyle. If in doubt, pregnant or taking medication, talk to your GP or pharmacist.
Spirulina and chlorella from GOYU
Organic 500 mg tablets: on their own, together in one tablet or as a combo deal.
