Reference
The questions our community asks weekly — answered once, calmly, and linked to longer reads where the topic deserves more space.
Most people do well at 1–3 g/day. The dose used in published trials ranges from 1 to 8 g depending on the goal. Start at 1 g/day for the first week, then increase by ~1 g/week until you reach your target. Use our dosage calculator for a personalised starting point.
There's no strong evidence timing matters. Convention is with a meal — mostly for tolerability, since spirulina on an empty stomach gives some people mild nausea. If you take it for athletic performance, dose 30–60 minutes before exercise.
Take spirulina at least an hour apart from coffee or tea. The tannins in both significantly reduce absorption of spirulina's non-haem iron. Citrus or vitamin C foods, in contrast, improve it.
Spirulina itself isn’t known to be teratogenic, and many midwives consider clean, well-tested spirulina acceptable in pregnancy at modest doses. The bigger risk is contaminated product — heavy metals and microcystins are far more dangerous in pregnancy than at other life stages. If you choose to take it, insist on a brand with recent third-party testing, stay at 1–2 g/day, and mention it at your antenatal visits. See who should avoid it for the full picture.
Spirulina has been used in food-aid programs for malnourished children for decades at 1–3 g/day. For well-fed children in non-clinical contexts, 250–500 mg is the typical small dose — but quality matters even more in children due to lower body weight. Discuss with a paediatrician.
It contains a B12 analog (pseudocobalamin) that is not biologically active in humans and may even compete with real B12 for absorption. If you are vegan and relying on spirulina for B12, you are not getting any. Take a methylcobalamin or cyanocobalamin supplement instead.
Yes — it contains all nine essential amino acids in usable proportions, with a profile roughly comparable to egg white. By dry weight, spirulina is 60–70% protein, but a typical 3 g daily dose only delivers ~2 g of protein, so it's not a substitute for dietary protein.
All three are the same dried biomass, just shaped differently. Tablets are easiest if you don't want to taste it (binders add ~5–10% non-spirulina mass). Powder is cheapest, most flexible, and most flavour-forward. Flakes are a middle ground for sprinkling on food.
Phycocyanin content, drying method, and freshness vary substantially between brands. A 12-month-old container of spray-dried spirulina tastes different — usually more bitter, more 'pond' — than a fresh batch of vacuum-dried. The difference is real, not imagined.
Sealed and stored in a cool, dark, dry place: about 18–24 months. Once opened, the clock speeds up — most of the colour and bioactivity is gone after 6 months in a half-empty jar in the kitchen. See our forthcoming storage guide for specifics.
Welcome to spirulina. The chlorophyll and phycocyanin colour everything that passes through. It's harmless and it goes away within a day of stopping. The same compounds that colour your output are colouring your morning smoothie, and most of them are absorbed normally.
For most medications, no. Documented concerns: warfarin and other anticoagulants (consistency matters more than dose), immunosuppressants (theoretical interaction), and anything that depends on stable thyroid metabolism (take spirulina at least an hour apart from levothyroxine, though it’s not a major iodine source). When in doubt, ask your pharmacist. Use our decision tool for a structured walk-through.
Yes, with one rule: avoid sustained heat above ~70 °C. Hot beverages, pesto on hot pasta tossed off the heat, or briefly-cooked fresh pasta all work. Boiling spirulina in soup or baking it at 180 °C destroys phycocyanin and the colour shifts to brown. Our recipes are calibrated for this.
Generally no. Wild-harvested has more variable quality and a higher risk of cyanotoxin contamination from co-occurring species. Well-controlled commercial cultivation is cleaner and more consistent. There are exceptional artisanal producers, but they're not the rule.
Both are microalgae, but chlorella is a true alga (eukaryote) and spirulina is a cyanobacterium. Chlorella has a tough cell wall that requires cracking for digestion; spirulina's cell walls are soft. Their nutrient profiles overlap but aren't identical — chlorella has more chlorophyll and CGF (chlorella growth factor), spirulina has more phycocyanin and protein.
Extracted phycocyanin — the blue pigment isolated from the rest of the spirulina biomass. Bright blue, used for colouring smoothie bowls and lattes. It carries phycocyanin's antioxidant properties but none of the protein, iron, or B-vitamins of whole spirulina. Perfectly fine food colouring; not a nutritional substitute.
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