Updated 20 October 2026. HealthyHey makes the spirulina products named in this guide. The research below is explained with its sources, so you can check it yourself.
Key Takeaways
- What it is: spirulina is a dried blue-green alga (Arthrospira platensis), sold as tablets, capsules and powder.
- Protein: dried spirulina is about 57 to 69% protein, but a supplement dose is small: 1 g gives about 0.6 g of protein and a 3 g scoop about 2 g.
- Vitamin B12: most of the B12 in spirulina is a form the body cannot use, so it is not a reliable B12 source.
- Research: trials found modest changes in blood lipids and blood pressure, mostly in people whose levels were raised, and reviews do not all agree.
- Quality: algae can pick up heavy metals and toxins when grown without controls, so look for published lab reports.
- Safety: a US Pharmacopeia review rated spirulina Class A. Avoid it with phenylketonuria, and speak to a doctor first if you have an autoimmune condition or take regular medicines.
What Spirulina Is
Spirulina is a microscopic blue-green alga, strictly a cyanobacterium, that grows in warm, alkaline water. The supplement is the dried, powdered alga, usually Arthrospira platensis; the label should name the species. In Hindi it is usually just called स्पिरुलिना, a नील-हरित शैवाल (blue-green alga). It is not related to moringa, which is a leaf powder.
How Much Protein Is in Spirulina?
By weight, a lot: the USDA lists 57.5 g of protein per 100 g of dried spirulina (USDA FoodData Central), and our powder's label states 69 g per 100 g. But supplement doses are measured in grams, not in bowls, so the protein you actually get is small:
| Amount of spirulina | Protein (at 60% protein) |
|---|---|
| One 500 mg tablet or capsule | About 0.3 g |
| 1 g (two 500 mg capsules) | About 0.6 g |
| 3 g (one level scoop of powder) | About 1.8 to 2 g |
| 10 g (about a heaped tablespoon) | About 6 to 7 g |
So spirulina adds little to a day's protein at supplement doses. If protein is your main goal, food or a protein powder will do more for the money.
Vitamin B12 and Iron
- Vitamin B12: labs that measure B12 with older microbial tests report high values for spirulina, but when spirulina tablets were analysed in detail, 83% of the B12-like compound was pseudovitamin B12, which the body cannot use (Watanabe 1999). The USDA lists 0 µg of B12. Do not rely on spirulina for B12.
- Iron: dried spirulina contains iron (28.5 mg per 100 g in the USDA data; our powder label states 49.8 mg per 100 g, or 1.49 mg per 3 g scoop). A 3 g serving gives a modest amount next to daily needs.
What the Research Shows
Most spirulina trials are small and short, and many enrolled adults whose blood lipids or blood pressure were already raised. They tell you what spirulina did in those groups, not what it will do for everyone.
- Blood lipids: a 2016 review of 7 trials reported lower total cholesterol, LDL cholesterol and triglycerides, and higher HDL cholesterol, with spirulina (Serban 2016). A 2025 review of 9 spirulina trials found no significant change in lipids (Pinto-Leite 2025). The evidence is mixed.
- Blood pressure: a 2025 review of 29 trials of edible algae found spirulina lowered blood pressure by about 5 mmHg systolic and 3.5 mmHg diastolic. Effects were clearer above 3 g a day for at least 12 weeks and in people whose blood pressure was raised (Casas-Agustench 2025). The other 2025 review found a small effect of uncertain clinical importance (Pinto-Leite 2025).
Spirulina is a food supplement, not a medicine. If your cholesterol or blood pressure is high, follow your doctor's advice; spirulina is not a substitute for medical care.
How Much Spirulina Do People Take?
Supplement labels usually give 1 to 3 g a day, and blood pressure trials used 1 to 8 g a day (Machowiec 2021). Larger amounts are easier as powder: 3 g is six 500 mg tablets. Start with the amount on your label, take it with water or food, and ask your doctor before taking more.
Heavy Metals and Algal Toxins
Because spirulina is grown in open water, it can absorb heavy metals from that water. If other algae get into the pond, it can also pick up toxins called microcystins. In a 2017 study of 18 supplements made from spirulina or another blue-green alga, 8 contained algal toxins above tolerable daily intake levels (Roy-Lachapelle 2017). Producers reduce the risk by growing spirulina in controlled ponds and testing batches. Indian food regulations (FSSR 2011) set heavy-metal limits for health supplements, for example lead 2.5 mg/kg and arsenic 1.1 mg/kg. Ask for, or look up, lab reports, and check what was tested: few brands publish microcystin results.
How to Choose a Spirulina Supplement
- Species on the label: Arthrospira platensis (or Spirulina platensis).
- Grams per serving: check the spirulina per tablet or capsule and how many the label asks for.
- Cost per gram: divide the price by the grams of spirulina in the pack.
- Published lab reports: look for heavy metals and microbiology, and for microcystin results if the brand has them.
- Organic claims: if a pack says organic, look for the India Organic or Jaivik Bharat logo; a brand name alone is not certification.
- Tablet or powder: powder is usually cheaper per gram; tablets and capsules are easier to take.
How to Compare Spirulina Prices
Work out the cost of 1 g of spirulina: for tablets and capsules, multiply the milligrams per unit by the count and divide the price by that total; for powders, divide the price by the net weight.
On healthyhey.com on 20 October 2026, HealthyHey Spirulina Capsules cost ₹759 for 120 capsules of 500 mg (60 g of spirulina, ₹12.65 per gram), and HealthyHey Spirulina Powder costs ₹413 for 100 g (₹4.13 per gram).
HealthyHey Spirulina: Labels and Lab Results
- Spirulina Capsules (label): 1,000 mg spirulina (Arthrospira platensis) and 10 mg natural vitamin E per serving of 2 vegetarian capsules, 0.6 g protein per serving, 120 capsules (60 servings). One serving a day with a meal. Labelled "Natural Antioxidant" and "Supports Cardiovascular Health".
- Spirulina Powder (label): 3 g per scoop, 33 servings per 100 g pouch, with vitamin E 5 mg per serving. Per 100 g: protein 69 g, iron 49.8 mg, beta carotene 181 mg. One scoop a day in water, a smoothie, dal or roti dough. Labelled "Natural Antioxidant" and "Supports Lipid Profile & Immune Health". "HealthyHey organic" on the pack is a brand name, not an organic certification.
- Lab reports: capsule page: heavy metals on batch NOFAZASPBP0108C1250105 (Avon Food Lab, NABL TC-11151, March 2026): lead 0.11 mg/kg; arsenic, cadmium and mercury below the quantitation limit. Microbiology on an earlier capsule batch (Accurate Universal Laboratories, June 2024): Salmonella and Listeria absent in 25 g. Powder page: heavy metals on batch NOFAZASPBP0108P1250103 (Avon, February 2026): lead 0.19 mg/kg, arsenic 0.34 mg/kg against a limit of 1.1 mg/kg; cadmium and mercury below the quantitation limit. Microbiology on batch NOFAZASPBP144P6250101 (Avon, July 2026): Salmonella and Listeria absent in 25 g. None of these reports measures protein or microcystins.
Who Should Be Careful With Spirulina
- Phenylketonuria (PKU): spirulina protein contains phenylalanine, so people with PKU should avoid it.
- Autoimmune conditions: case reports have linked spirulina-containing supplements to flares of autoimmune skin and muscle conditions (Lee and Werth 2004). If you have an autoimmune condition or take medicines that suppress the immune system, ask your doctor first.
- Pregnancy, breastfeeding and children: speak to a doctor before use.
- Regular medicines: speak to your doctor before starting.
- Overall safety: a US Pharmacopeia expert committee reviewed trials, animal data and 31 adverse event reports and gave spirulina its Class A safety rating (Marles 2011). Mild stomach upset is the usual complaint.
Frequently Asked Questions
How much protein is in one spirulina tablet?
Very little. Dried spirulina is about 57 to 69% protein, so a 500 mg tablet gives about 0.3 g of protein and a 3 g scoop of powder about 2 g. At supplement doses, spirulina is not a practical way to meet your daily protein needs.
Is spirulina a good source of vitamin B12?
No. Most of the B12 measured in spirulina is pseudovitamin B12, a form the body cannot use. Vegetarians and vegans should rely on a B12 supplement or fortified foods instead.
Spirulina tablets or powder: which is better?
They are the same ingredient. Powder usually costs less per gram and makes larger amounts easy; tablets and capsules are convenient and have no taste. Compare the grams of spirulina per serving and the cost per gram.
How much spirulina should I take a day?
Supplement labels usually give 1 to 3 g a day, and studies have used about 1 to 8 g a day. Take the amount on your label, and ask your doctor before going higher.
Is spirulina the same as moringa?
No. Spirulina is a blue-green alga grown in water; moringa powder is made from the leaves of the drumstick tree. Some products mix the two.
Can spirulina contain toxins?
It can if it is grown without quality control. Algae supplements have been found contaminated with toxins called microcystins and with heavy metals. Choose brands that publish lab reports, and check what each report tested.
Is spirulina safe to take every day?
A US Pharmacopeia safety review gave spirulina its Class A safety rating. Follow your label. Avoid it if you have phenylketonuria, and speak to a doctor first if you have an autoimmune condition, take regular medicines, or are pregnant or breastfeeding.
Our Recommendation
Decide why you want spirulina. For protein or vitamin B12 it is a poor choice at supplement doses. As a daily green supplement, choose a product that names the species, states the grams per serving and publishes heavy-metal and microbiology reports. Then compare the cost per gram: powder is usually cheaper, and tablets or capsules are easier. If you have an autoimmune condition, PKU or take regular medicines, talk to your doctor first.
Sources
- US Department of Agriculture, FoodData Central. Seaweed, spirulina, dried (FDC ID 170495, SR Legacy): protein 57.5 g, iron 28.5 mg and vitamin B12 0.0 µg per 100 g. fdc.nal.usda.gov
- Watanabe F 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
- Serban MC et al. A systematic review and meta-analysis of the impact of Spirulina supplementation on plasma lipid concentrations. Clin Nutr. 2016;35(4):842-851. doi:10.1016/j.clnu.2015.09.007
- Pinto-Leite M et al. The role of Chlorella and Spirulina as adjuvants of cardiovascular risk factor control: a systematic review and meta-analysis of randomised controlled trials. Nutrients. 2025;17(6):943. doi:10.3390/nu17060943
- Casas-Agustench P et al. Edible algae reduce blood pressure in humans: a systematic review and meta-analysis of randomised controlled trials. J Hum Nutr Diet. 2025;38(4):e70095. doi:10.1111/jhn.70095
- Machowiec P et al. Effect of Spirulina supplementation on systolic and diastolic blood pressure: systematic review and meta-analysis of randomized controlled trials. Nutrients. 2021;13(9):3054. doi:10.3390/nu13093054
- Marles RJ et al. United States Pharmacopeia safety evaluation of spirulina. Crit Rev Food Sci Nutr. 2011;51(7):593-604. doi:10.1080/10408391003721719
- Roy-Lachapelle A et al. Detection of cyanotoxins in algae dietary supplements. Toxins (Basel). 2017;9(3):76. doi:10.3390/toxins9030076
- Lee AN, Werth VP. Activation of autoimmunity following use of immunostimulatory herbal supplements. Arch Dermatol. 2004;140(6):723-727. doi:10.1001/archderm.140.6.723
- Food Safety and Standards (Contaminants, Toxins and Residues) Regulations, 2011 (FSSR), heavy-metal limits as listed on the lab reports above.
This guide is general information, not medical advice. Prices and labels were checked on 20 October 2026.