# Best Soy Isoflavones by cost per dose

Source page: https://www.vitamindbc.com/best/soy-isoflavones · prices checked 2026-11-13 · 11 rankable products

## Short answer

The cheapest soy isoflavones we track costs **$0.078 per serving**, against a median of $0.147 across the 11 products we can price per dose. Cost per dose is the current retail price divided by servings, as of 2026-11-13; it is not the sticker price, and the cheapest bottle is rarely the best value.

## Ranking, cheapest dose first

| # | Product | Form | Servings | Cost per serving | Value Index |
|---|---|---|---|---|---|
| 1 | Soy isoflavone 100 mg with Agnus castus | capsule 100mg | 90 | $0.078 | 1.9× |
| 2 | Nutricost Soy Isoflavones 150mg | capsule 150mg | 180 | $0.105 | 1.4× |
| 3 | Best Naturals Soy Isoflavones 750 mg 120 Capsules… | capsule 750mg | 360 | $0.106 | 1.4× |
| 4 | Best Naturals Soy Isoflavones 750 mg 120 Capsules… | capsule 750mg | 240 | $0.112 | 1.3× |
| 5 | Best Naturals Best Naturals Soy Isoflavones for Women 750 Mg… | capsule 750mg | 120 | $0.125 | 1.2× |
| 6 | Swanson Soy Isoflavones Standardized 750 mg, 120 Capsules | capsule 750mg | 120 | $0.147 | 1.0× |
| 7 | NOW Foods Supplements, Soy Isoflavones, 60 mg… | capsule 60mg | 120 | $0.157 | 0.9× |
| 8 | Puritan's Pride Non-GMO Soy Isoflavones 750mg | capsule 750mg | 120 | $0.167 | 0.9× |
| 9 | Swanson Soy Isoflavones Bone and Menopause 750 mg | capsule 750mg | 60 | $0.180 | 0.8× |
| 10 | CBI Natural Soy Isoflavones 2.5:1 Extract 500mg | capsule 500mg | 120 | $0.225 | 0.7× |
| 11 | Webber Naturals Soy Isoflavones 50mg 90 Capsules | capsule 50mg | 90 | $0.332 | 0.4× |


## Method and attribution

Value Index = the median cost per dose of the whole shelf ÷ this row's; 1.0 is the median product, 2.0 means a dose costs half the typical one. Arithmetic only — no judgement of evidence or quality: https://www.vitamindbc.com/methodology#value-index.
Cost per dose, the glitch guards and the combination-product rule: https://www.vitamindbc.com/methodology.
Cite as "VitaminDB (vitamindbc.com)". Retailer prices are not republished here; open the source page for a live price.