Chlorella vulgaris
EVIDENCE: MODERATEAlso sold as: chlorella, cracked cell chlorella, broken cell wall chlorella, green algae
Chlorella is a microalga studied at gram-level daily amounts. Trial reviews report modest reductions in cholesterol and blood pressure. No human study identified here tests chlorella for teeth, gums, or breath.
Compiled by iSupplementReviews editorial team ·Updated 2026-10-13 · 4 sources
- Type
- Green microalga (whole-food supplement)
- Studied dose
- 1–15 g/day (meta-analyses cluster ~1–4 g/day; lipid/BP effects mostly >4 g for ≥8 weeks)
- Best form
- cracked-cell-wall powder or tablets — the hard cell wall must be broken for the nutrients to be absorbable
- Upper limit
- No established upper intake limit established — gram-level doses are well-tolerated in trials
- Our rating
- MODERATE — Several human trials — limits in size, duration, or independence
What is chlorella vulgaris?
Chlorella vulgaris is a single-celled green alga containing protein, pigments, and micronutrients. It is roughly half protein by weight. Its hard cell wall limits digestion, which is why products identify broken or cracked cell walls. Human research mainly concerns cholesterol and blood pressure.
Where the evidence lives
| Endpoint | Evidence | Effect size | Verdict |
|---|---|---|---|
| Total/LDL cholesterol | Meta-analysis of 19 trials | TC −9.1, LDL −8.3 mg/dL | Supported — modest |
| Blood pressure | Same meta | SBP −4.5, DBP −1.6 mmHg | Supported — modest |
| Fasting glucose | Same meta | FBG −4.2 mg/dL | Supported — small |
| Maximal oxygen uptake | Single small trial | VO2max ↑ in 20 young men | Early positive |
| Teeth, gums, breath | None | — | Not studied |
The Fallah 2018 meta-analysis is the anchor: 19 randomized trials, significant effects concentrated in the >4 g/day and ≥8-week subgroups. A 2022 dose-response meta pinned the LDL effect to ≤1.5 g/day territory. Real research, for a different product category.
The “oxygenation” connection
A small exercise study found improved maximal oxygen uptake with chlorella. That finding does not establish improved oxygen delivery to the gums.
One small trial, Zempo-Miyaki 2017, found chlorella supplementation increased maximal oxygen uptake in 20 young men. It’s the only study in the file that touches anything like ‘oxygen,’ and it’s an exercise-physiology outcome in athletes, not gum oxygenation. This exercise study does not establish that chlorella improves oxygen delivery to the gums.
What dose was studied?
| Goal | Dose | Duration |
|---|---|---|
| Lipids/BP (meta-significant) | >4 g/day | ≥8 weeks |
| VO2max | ~chlorella tablet regime, gram-level | 4 weeks |
| Supplement-typical | 1–3 g/day | — |
Inside a 120 mg blend shared with three other ingredients, a chlorella share might run ~10–40 mg, roughly 1–4% of the lowest studied doses.
Side effects
Mild at studied doses: nausea, green stool, occasional allergic-type reactions. Warfarin interaction is the real flag; chlorella carries meaningful vitamin K. Quality varies: the meta-analysis noted only 2 of 10 trials verified their supplement’s purity.
Drug interactions
- Warfarin: vitamin K counteraction is documented
- Immunosuppressants: chlorella has mild immune-stimulating signals in trials
Who should not take it?
Warfarin users (without INR management), people with algae or mold sensitivities, and pregnant women (insufficient safety data).
What the authorities say
No health body endorses chlorella for any condition; the trial base is what it is: genuine cardiometabolic signals at gram doses, everything else extrapolation.
What to know about chlorella vulgaris
Chlorella’s human research uses grams daily for metabolic measures, rather than dental outcomes. A cracked-cell specification helps identify the preparation, but does not prove oral-health benefits or establish the effect of a small blend amount.
Frequently asked questions about Chlorella vulgaris
What is chlorella vulgaris?
A single-celled freshwater green alga: one of the most chlorophyll-dense foods known (~1–4% chlorophyll by weight), plus protein (~50–60%), carotenoids, and B-vitamins. 'Cracked cell' or 'broken cell wall' on a label is not marketing; the rigid wall must be mechanically disrupted or the nutrients pass through unabsorbed.
What is chlorella proven to do?
The strongest file is cardiometabolic: a meta-analysis of 19 trials found significant reductions in total cholesterol (~−9 mg/dL), LDL (~−8 mg/dL), systolic blood pressure (~−4.5 mmHg), and fasting glucose (~−4 mg/dL). Real effects, modest sizes, mostly at doses above 4 g/day for 8+ weeks. Smaller trials cover antioxidant status and even maximal oxygen uptake.
Does chlorella help teeth, gums, or breath?
No human study has tested it for any oral outcome. Its chlorophyll content is the marketing bridge; chlorophyll derivatives have laboratory odor-neutralizing data. But swallowing microgram-adjacent chlorella inside a blend is not the thing that was ever studied for breath.
How much chlorella was used in the trials?
Roughly 1–15 g/day, with the lipid and blood-pressure signal concentrated above ~4 g/day for at least 8 weeks. Milligram amounts inside a proprietary blend are 1–2 orders of magnitude below the trial floor.
Is chlorella safe?
Generally yes at studied doses; digestive upset and green-tinged stool are the common complaints. Real cautions: vitamin K content can counteract warfarin, and contamination/quality varies by producer (only two of ten trials in one meta-analysis verified supplement purity).
References
- [1]Fallah AA et al. — Chlorella supplementation on cardiovascular risk factors: meta-analysis of 19 RCTs (Clin Nutr, 2018)
- [2]Chlorella vulgaris on lipid profile in adults — dose-response meta-analysis of RCTs (Complement Ther Med, 2022)
- [3]Zempo-Miyaki A et al. — Chlorella supplementation and maximal oxygen uptake in young men (J Clin Biochem Nutr, 2017)
- [4]Cochrane review — interventions for managing halitosis (what has and hasn't been trialed)