New Research Characterizes SloIron® Activity

Plant-based ferritin-bound iron shown in clinical trials to deliver iron efficiently, addressing deficiency and maintaining normal balance.

WALNUT CREEK, Calif. – Iron deficiency is the most common nutritional deficiency in the world, representing a major health challenge across diverse populations globally, with its most severe form—iron deficiency anemia—affecting up to 2 billion individually worldwide. Iron insufficiency is also a growing concern. Iron supplementation is effective at replenishing iron stores; however, it is limited by issues including tolerability, absorption and physiological regulatory feedback mechanisms.

In contrast, ferritin-iron, wherein the iron is contained within a ferritin protein shell as a bionanomineral called Ferrihydrite (Fe203H20), appears to have similar absorption and bioavailability to traditional ferrous sulfate, without the side effects. Instead, the ferritin “cage” serves as a natural enteric coating for the Fe and is not broken down inside the stomach; instead, when it reaches the gut, the gut cell absorbs the ferritin protein cage as a whole using a dedicated absorption mechanism, avoiding direct exposure of Fe to the gut wall, which can cause irritation.

New research on SloIron® ferritin-iron characterizes its pharmacokinetic impact and impact on biomarkers of iron metabolism in healthy and iron-deficient women. The research generated two scientific manuscripts, one which was just published (EC Nutrition. 2026;21(6):01-09); top line findings for the second trial, which is still in the review process, are now available.

In the first trial, researchers found SloIron could produce a smooth, sustained rise in serum iron over 24 hours, rather than the traditional spike seen with high-dose iron salts. Further, in women with iron deficiency anemia, 30 days of supplementation with SloIron was associated with clear improvements in key iron status biomarkers; further, iron-regulated regulatory hormones remained in expected ranges, indicating ferritin-bound iron works in concert with the body’s iron control mechanisms.

The second trial evaluated the impact of SloIron compared to ferrous bisglycinate in two phases. SloIron demonstrated a more gradual serum iron response than ferrous bisglycinate following a single dose, while producing comparable improvements in iron status biomarkers over 28 days in healthy women and those with iron deficiency anemia. Serum ferritin increased substantially in both populations receiving SloIron, and additional improvements were observed in measures related to iron transport and utilization.

“I was impressed with the impact of SloIron on iron metabolism and biomarkers of iron health. The findings surprised me because of SloIron being a  non-heme iron,” said Dr Douglas Kalman, PhD, RD, of Nova Southeastern University and Substantiation Sciences.

Further, Dr Kalman noted: “The fact that SloIron moves the iron health needle within hours of ingestion and that the impacts demonstrate continual improvement and maintenance of biomarkers of iron health over time, makes this an exciting option for those who need or seek supplemental iron.”

SloIron was originally introduced to the North American market in 2020, and remains an iron ingredient of choice, with absorption equivalent to traditional sources, without the side effects.

“Despite the growing need for iron supplementation, many consumers struggle with the absorption and gastrointestinal side effects associated with conventional iron, which can ultimately compromise compliance,” said Vincent Hackel, president and CEO, SloIron, Inc. “This new pharmacokinetic research reinforces the potential of SloIron to deliver iron in a form that is both highly absorbable and gentle, addressing a critical need as the global iron supplement market is topping US$3 billion, growing at 5% annually. We see an even greater opportunity to bring this technology to emerging markets where nutrient absorption is increasingly important—including women’s health and the rapidly expanding population using GLP-1 medications.”