Everything DoseRank tracks on the grapefruit seed extract shelf — Citrus Bioflavonoids. The category itself is never ranked: 19 products get scored the moment you say what you want them to do.
How to read the scores
This legend covers the scores on this page — for data sources, scoring weights, and limits, read the full methodology →
Answer a few questions about your goals, habits, stack, and budget. Then, DoseRank will find the products that best match your needs based on your answers. It's free and only takes 60 seconds! No account is required.
A saved, shareable breakdown: your matched products, dose math, interaction flags to discuss with a clinician, and a price-tracked stack you can revisit.
Questions
Each product gets a composite score blending clinical strength, evidence, dose fit, trust and value — computed for the goal you picked, across this category's products. The #1 on the DoseRank tab has the highest composite; the other tabs re-rank the same products by Value, Trust, or Popularity. Placement is never paid.
Start with a goal, not a brand
Browsing grapefruit seed extract supplements without a goal makes no sense — different products do different jobs, and “best” flips depending on which job you're hiring for. These are the 14 health outcomes that matter for this category. Pick yours, and the full evidence-ranked shelf loads for that goal alone.
EdemaSwelling due to excess fluid accumulation.19 rankedStrong
MicrocirculationPerfusion in small vessels and capillary beds.18 rankedStrong
Endothelial functionAbility of blood vessels to dilate and respond normally.18 rankedModerate-strong
Zinc statusBiochemical sufficiency of zinc.6 rankedStrong
Antioxidant capacityMeasured ability to counter oxidative stress.19 rankedStrong
Vitamin C statusBiochemical sufficiency of ascorbic acid.6 rankedStrong
Blood pressureArterial pressure; direction of benefit depends on baseline status.19 rankedStrong
Vitamin E statusBiochemical sufficiency of tocopherols/tocotrienols.4 rankedStrong
Acne severityExtent or intensity of acne lesions.6 rankedModerate-strong
Sperm motilityAbility of sperm to move effectively.4 rankedModerate-strong
Common cold durationLength of cold episodes.8 rankedModerate-strong
Vascular functionOverall health and reactivity of the circulatory system.1 rankedModerate-strong
Nitric oxide bioavailabilityAvailability of nitric oxide relevant to vascular function.1 rankedModerate-strong
Oxidative stress biomarkersLaboratory indicators of oxidative damage or redox imbalance.1 rankedModerate-strongNothing is ranked yet — the shelf stays locked until you pick a goal.
No goal, no ranking.
A “best grapefruit seed extract supplement” list without a goal would be marketing, not evidence. Pick what you want to improve and DoseRank scores all 19 products against that goal's trials.