Both contain 10.5mg of the same highly absorbable heme iron. Proferrin ES comes in easy-swallow tablets, while Proferrin Clear uses dye-free capsules and is NSF Certified for Sport. Choose ES if you prefer tablets over capsules. Choose Clear if you need NSF Certification for competitive sport testing.

Heme iron uses your body's natural absorption pathway—the same one that processes iron from meat. It bypasses the pathway that causes nausea and constipation with standard iron pills, delivering 10-23x better absorption with minimal side effects.

Most athletes notice energy improvements within 2-4 weeks. Ferritin levels typically increase after 8-12 weeks of consistent supplementation. Get bloodwork after 8-12 weeks to assess progress and adjust dosing.