Chlorella dosage: how many tablets per day?
Short answer: There is no official recommended amount of chlorella, so you follow the label. Our chlorella tablets say 3 tablets of 500 mg twice a day, with or right after a meal: 3 grams of chlorella per day in total. In human studies, participants usually took 5 to 10 grams per day, for a few weeks up to three months. That tells you what has been studied, not what you should take.
Last updated: 5 November 2026 · Written by Florian Fermin
"How many chlorella tablets per day?" is a question we get a lot. The answer seems simple, but the right chlorella dosage depends on the product: chlorella on its own, a tablet with spirulina added, or two packs side by side. Below I work it out per product, show which amounts have been used in research and explain when to talk to a doctor first.
What chlorella is and what to look out for is covered in our article chlorella: what is it and is it safe.
How much chlorella per day?
Do not take more than the daily dose on the packaging. Unlike vitamins, chlorella has no official recommended daily amount. So the label is your guide:
| Product | Directions on the label | Chlorella per day | How long it lasts |
|---|---|---|---|
| Chlorella Tablets 500 mg Organic (300 tablets) | 3 tablets twice a day with water, with or right after a meal | 3 g (6 x 500 mg) | 50 days |
| Spirulina Chlorella Tablets 500 mg Organic (300 tablets) | 3 tablets twice a day with water | 1.5 g chlorella and 1.5 g spirulina | 50 days |
| Chlorella & Spirulina Tablets Combo Deal (2 x 300 tablets) | from each pack, 3 tablets twice a day | 3 g chlorella and 3 g spirulina | 50 days |
The milligrams per tablet are on our labels. I calculated the grams per day and the number of days from those.
How many chlorella tablets per day?
Of our chlorella tablets you take 6 a day: 3 with one meal and 3 with another, with water. Each tablet contains 500 mg of organic chlorella (Chlorella pyrenoidosa), so that adds up to 3 grams.
If you use chlorella from another brand, convert it back to grams. The weight per tablet differs per brand. What else to look for when choosing tablets is covered in chlorella tablets: what to look for.
- Find the number of milligrams of chlorella per tablet on the label.
- Multiply by the number of tablets per day: 6 x 500 mg = 3,000 mg.
- Divide by 1,000 to get grams: 3,000 mg is 3 g.
- Divide the number of tablets in the pack by the number per day: 300 / 6 = 50 days.
You don't have to start with 6 tablets straight away. Taking less than the label says is always fine. Personally, I would start the first few days with 3 tablets at one meal and then build up. That is my own advice, not a rule from the label.
How much chlorella has been used in research?
In the human studies discussed in a 2020 review, participants usually took 5 to 10 grams of chlorella per day, for a few weeks up to three months (Bito et al., 2020). Two of the four authors of that review work for a chlorella producer; that is good to know.
A few examples of the amounts used:
- In American studies, participants took 10 grams of chlorella in tablet form plus 100 ml of a liquid chlorella extract every day, for two to three months (Merchant and Andre, 2001).
- In a small pilot study without a control group using the same amount, the researchers found no notable changes in standard blood values after two months (Merchant et al., 2000).
I am deliberately leaving out what else these studies found. The EU has not authorised any health claims for chlorella itself, and the groups were small. I only mention them to show which amounts have been studied. The 3 grams in our tablets is below that.
What is allowed is this nutrition claim for our chlorella tablets: Chlorella is naturally high in protein**.
**Authorised health claim (Regulation (EU) No 432/2012) or nutrition claim (Regulation (EC) No 1924/2006).
When should you take chlorella?
Take chlorella during or right after a meal, as our packaging says. The best time of day, morning or evening, has not been studied.
- Split it over 2 moments: for example 3 tablets with breakfast and 3 with dinner.
- With water: swallow the tablets with a glass of water. You will hardly taste the alga.
- Forgot a dose? Simply take the next portion at the next moment, not a double amount.
- Storage: dry and cool, out of reach of children. Do not use the tablets if the seal is broken.
Chlorella and spirulina together: how much do you take?
If you use both chlorella and spirulina, follow the daily dose on the label of each product. Also add up how much chlorella you get in total:
- Spirulina Chlorella Tablets: 250 mg of chlorella and 250 mg of spirulina per tablet. At 6 tablets a day that is 1.5 g of each. Note: this tablet contains Chlorella vulgaris, the single chlorella tablets contain Chlorella pyrenoidosa.
- Chlorella & Spirulina Combo Deal: 6 chlorella tablets and 6 spirulina tablets a day, 3 g of chlorella and 3 g of spirulina in total.
- Daily Greens: contains 4% chlorella. One 8 g scoop provides about 0.3 g of chlorella (calculated).
If you take the single chlorella tablets and the Spirulina Chlorella Tablets at the same time, you end up at 4.5 g of chlorella per day. That is more than the label of either product recommends on its own. In that case, better choose one of the two. How spirulina and chlorella differ and how to take them together is explained in spirulina vs chlorella. How much spirulina to take per day is covered in spirulina dosage.
Can you take too much chlorella?
Yes. More is not better, and we have not found large studies on what happens with a lot of chlorella over a long period. So stick to the label. The side effects described in the literature come mainly from individual case reports: allergic reactions, skin reactions in the sun and a single reaction in the kidneys. I list them in chlorella side effects.
If you get complaints after starting, take less or stop, and see your GP if they persist.
Who should talk to a doctor first?
Talk to your GP or pharmacist first if you are pregnant, breastfeeding, taking medication or have a medical condition. Our packaging says so. In addition:
- Blood thinners: chlorella contains vitamin K. If you use warfarin or another vitamin K antagonist, talk to your anticoagulation clinic or pharmacist first.
- Children: our packaging does not give a dosage for children. Do not give them chlorella without consulting a doctor.
- Algae allergy: do not use chlorella.
- Spirulina Chlorella Tablets: the label states that they contain beta-carotene, which is not recommended for smokers.
Summary in 3 points
- There is no official daily amount of chlorella. Our chlorella tablets say 3 tablets of 500 mg twice a day, 3 grams in total, and a pack lasts 50 days.
- In studies, people usually took 5 to 10 grams per day, for a few weeks up to three months. That is what has been studied, not advice.
- If you combine chlorella with spirulina or Daily Greens, add it up and stay within the daily dose. Talk to a doctor first if you use blood thinners, are pregnant or take medication.
Frequently asked questions
How many chlorella tablets per day?
For our 500 mg tablets, that is 3 tablets twice a day, with water and with or right after a meal. That is 6 tablets and 3 grams of chlorella per day. Do not take more than that.
How many grams of chlorella per day?
There is no official amount. Our label says 3 grams per day. In studies, participants usually took 5 to 10 grams per day, but those were small, short studies and not advice for daily use.
When is the best time to take chlorella?
During or right after a meal, as the label says. The best time has not been studied, so spread the tablets over two meals that fit your day.
How long can you use chlorella?
The directions are meant per day and do not mention a maximum duration. The studies lasted a few weeks up to three months, so little is known about use over many years. Talk to your GP if in doubt.
Can I take chlorella and spirulina together?
Yes. Choose the Spirulina Chlorella Tablets or the combo deal and follow the daily dose on the label. Don't add single chlorella tablets on top, or you will exceed the daily dose.
Sources
- Bito T, Okumura E, Fujishima M, Watanabe F. Nutrients. 2020;12(9):2524. doi:10.3390/nu12092524 (review; two authors work for a chlorella producer)
- Merchant RE, Andre CA. Altern Ther Health Med. 2001;7(3):79-91. PubMed 11347287 (review of the authors' own randomised studies)
- Merchant RE, Carmack CA, Wise CM. Phytother Res. 2000;14(3):167-173. doi:10.1002/(SICI)1099-1573(200005)14:3<167::AID-PTR560>3.0.CO;2-R (pilot study without control group, 20 participants)
- Product pages and packaging texts of Chlorella Tablets, Spirulina Chlorella Tablets, the Chlorella & Spirulina Combo Deal and Daily Greens, consulted 5 November 2026.
You can find all our chlorella tablets on the page 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.
Chlorella from GOYU
Organic 500 mg tablets: on their own, together with spirulina in one tablet or as a combo deal.
