SuppRanked21st Century
21st Century sells an estimated 19.7K units a month on Amazon across 5 Best Sellers products, worth roughly $163K/mo in gross revenue at list price (a modeled estimate, not Amazon data). That puts it #169 of 935 tracked supplement brands by SuppRanked score and #432 by estimated revenue. It peaks at #14 in Amazon's Iron Best Sellers list. Its biggest niche is calcium, where it is #23 by estimated revenue with about 1% of that top 100's est. sales. The top seller is 21st Century Fish Oil 1000mg Omega-3 Softgels, Mercury-Filtered… at ~$47K/mo est.
Categories Ranked in 4 Best Sellers lists · best position shown
21st Century products on Amazon Best Sellers Sorted by est. revenue/mo
| Product | Est. revenue/mo |
|---|---|
| 21st Century Fish Oil 1000mg Omega-3 Softgels, Mercury-Filtered, 120ct | Omega-3 Fish Oil… ASIN B0016OJVX6 · #42 Fish Oil (Omega-3) · 4.1K units | $47K |
| 21st Century Slow Release Iron 45mg Tablets, Gentle on Stomach, 60 Count | High-Potency… ASIN B00582WT6I · #14 Iron · 8.9K units | $44K |
| 21st Century Calcium 600mg Tablets, Bone Strength Support, 400 Count | Calcium Carbonate… ASIN B00M5TZ1F8 · #22 Calcium · 3.2K units | $38K |
| 21st Century Calcium Citrate + D3 Petites, Easy to Swallow, 200 Count | Highly Absorbable… ASIN B00O1ZV4M8 · #60 Calcium · 1.6K units | $17K |
| 21st Century Calcium Citrate Plus D Maximum Caplets, 120 Count | Maximum-Strength Highly… ASIN B00F6WRNFC · #45 Calcium · 1.9K units | $16K |
Prices, ratings and ranks as seen on October 15, 2026. Links go to the product on Amazon.com.
Competitors & comparisons
Top rivals in Calcium
- Life Extension · $85K/mo est.
- NOW Foods · $75K/mo est.
- KIDNEY · $74K/mo est.
- Bariatric Fusion · $66K/mo est.
- BariatricPal · $59K/mo est.
- BariMelts · $59K/mo est.
Brands ranked near 21st Century
- #165 MegaRed · $605K/mo est.
- #166 ALPHA LION · $453K/mo est.
- #167 Dose · $3M/mo est.
- #168 ZBiotics · $909K/mo est.
- #170 AlgaeCal · $1.4M/mo est.
- #171 ORGANIC INDIA · $568K/mo est.
- #172 VELOMIX · $250K/mo est.
- #173 Floradix · $620K/mo est.
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How is 21st Century ranked?
The score (0–100) blends estimated monthly units (60%), category rank visibility (30%) and breadth across categories (10%). Est. revenue/mo is estimated units × list price, summed across the brand's ranked products. Methodology