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Enfamil ProSobee Simply Plant-Based vs Similac Soy Isomil
In independent testing, Similac Soy Isomil showed lower heavy-metal levels overall (purity 55 vs 49). The full lab numbers, metal by metal:
| Purity score | 49D | 55C |
| Lead ppb | 2.8 | 3.6 |
| Inorganic Arsenic ppb | 7.9 | — |
| Total Arsenic ppb | 10.3 | 4.7 |
| Cadmium ppb | 6.2 | 9.2 |
| Aluminum ppb | — | 89 |
| Price | $1.48/oz | $0.88/oz |
| Est. cost at 28 oz/day | $6.44/day | $3.81/day |
| Origin | US | US |
| Base | Soy | Soy |
| Buy | Buy |
EnfamilProSobee Simply Plant-Based
SimilacSoy Isomil
Lab data: Consumer Reports independent testing, March 2025. Purity scores are relative to the tested cohort — methodology. Not medical advice; consult your pediatrician.