Dried blue-green algae taken daily. Pooled trials show blood fats shift favorably, blood pressure edges down, body weight and body fat fall slightly, and a marker of inflammation declines. Hay-fever, blood sugar, antioxidant and fatigue signals rest on fewer studies. The main constraint is the product: open-pond growing lets liver-damaging toxins and lead into retail brands. (Full Review)

Protocol

Standard dose range

2–8 g daily

Whole dried biomass, with 1–10 g the outer bounds. Above 10 g adds nucleic acid load without documented added benefit.

Dose for lipid and pressure endpoints

4–8 g daily

Higher doses produced larger effects, and lipid trials clustering at 4 g and above produced the clearest separations from placebo.

Split versus single dosing

2–3 doses with meals

Breakfast and the evening meal. Splitting reduces the gastrointestinal load and smooths the blood pressure effect across the day.

Time to effect

Lipids and blood pressure

4–12 weeks

The pooled pressure effect was larger beyond eight weeks.

Hemoglobin

2 weeks

Rose 3.4% after 14 days at 6 g daily, with no accompanying performance gain.

Subjective fatigue

Within hours

Mental fatigue scores improved within four hours at 3 g daily.

Benefits

High: Improved blood lipid profile, lower blood pressure, reduced body weight and body fat

Medium: Lower systemic inflammation, improved glycemic control (conflicted), reduced allergic rhinitis symptoms, raised antioxidant capacity

Low: Higher hemoglobin concentration, reduced exercise-induced fatigue, improved metabolic syndrome liver markers, antiviral effect in chronic viral infection (conflicted), improved sleep quality

Speculative: Memory and visual learning in mild cognitive impairment, reduced arterial stiffness

Contraindications

Phenylketonuria of any severity

Solid-organ transplant recipients and anyone on maintenance immunosuppression

Active autoimmune disease (systemic lupus erythematosus, dermatomyositis, pemphigus)

Hereditary hemochromatosis, or ferritin above 300 ng/mL (men) or 200 ng/mL (women)

Pregnancy and lactation

Children

Documented allergy to spirulina or other cyanobacteria

Decompensated liver disease, Child-Pugh Class B or C

The two weeks before elective surgery

Key Interactions

Anticoagulants and antiplatelets (warfarin, apixaban, clopidogrel, aspirin)

Antihypertensives (lisinopril, losartan, amlodipine)

Glucose-lowering drugs (metformin, glipizide, insulin)

CYP1A2 substrates (caffeine, theophylline, tizanidine, clozapine, olanzapine)

Over-the-counter analgesics (acetaminophen, ibuprofen, naproxen)

Immune-stimulating supplements (echinacea, astragalus, chlorella, alfalfa, reishi)

Blood-pressure-lowering supplements (beetroot nitrate, garlic extract, magnesium, omega-3 fatty acids)

Blood-glucose-lowering supplements (berberine, chromium, cinnamon, alpha-lipoic acid)

Iron supplements and iron-fortified formulas

Sauna, fasting, endurance training

Risk & Side Effects

High: Cyanotoxin contamination, heavy metal contamination

Medium: Immune stimulation and autoimmune flare, gastrointestinal upset

Low: Allergic reaction including anaphylaxis, hepatotoxicity, rhabdomyolysis, elevated uric acid from nucleic acid load

Speculative: Neurodegeneration from BMAA exposure, masking of vitamin B12 deficiency

Monitoring

Marker	Target	Why
LDL cholesterol	70–100 mg/dL	Primary benefit endpoint
Triglycerides	50–80 mg/dL	Second lipid endpoint, most responsive
HDL cholesterol	50–70 mg/dL (men), 60–80 mg/dL (women)	The fraction spirulina raises
Blood pressure	110–120 / 70–78 mmHg	Primary benefit endpoint
hs-CRP	<0.8 mg/L	Inflammation endpoint
Fasting glucose	75–86 mg/dL	Glycemic endpoint and hypoglycemia guard
HbA1c	4.8–5.3%	Long-term glycemic control
Ferritin	50–100 ng/mL (men), 30–80 ng/mL (women)	Iron overload guard
ALT	<20 U/L (men), <17 U/L (women)	Hepatotoxicity and contamination guard
AST	<20 U/L	Second liver marker
Uric acid	3.5–5.5 mg/dL	Nucleic acid load guard
Creatine kinase	No established target for this purpose; track change from the individual's own baseline	Rhabdomyolysis guard
Blood lead	No established optimum; track change from the individual's own baseline	Contamination guard
Vitamin B12 with methylmalonic acid	B12 500–1,300 pg/mL, methylmalonic acid <0.27 µmol/L	Detects the inactive-analogue problem

Cadence: Full baseline draw before starting. Lipid panel, C-reactive protein, and liver panel at 12 weeks, then annually. Ferritin at 3 and 12 months, then annually. Blood pressure weekly for the first month, then monthly. Creatine kinase and blood lead symptom-driven or contamination-driven rather than routine.

Qualitative Assessment

Digestive comfort in the first two weeks, where the dominant adverse effect appears
Nasal congestion, sneezing, and sense of smell, if allergic rhinitis is the target endpoint
Perceived exertion and recovery quality after habitual training sessions
Sleep latency and continuity, the endpoint moved in the one trial to measure it
Any new photosensitive rash, joint swelling, or unexplained muscle weakness, a stop signal rather than a trend to watch
Standing lightheadedness, which flags the additive blood pressure effect before a reading does

Spirulina for Health & Longevity

Protocol

Benefits

Risk & Side Effects

Monitoring

Qualitative Assessment