Benefits
Hemoglobin and ferritin in pregnant women with low iron stores
In a 4-week open-label trial of 111 pregnant women with low iron, a 27 mg iron SunActive Fe tablet (with vitamin C, B12 and folic acid) raised hemoglobin by 2.63 g/dL, matching 100 mg of iron as ferrous ascorbate (2.62 g/dL); ferritin rose similarly. Costs were paid by the tablet's marketer, and a 27-woman study without a control group saw similar rises.
Fewer stomach complaints than other iron forms in two trials
In the pregnancy trial, 6 of 54 women on ferrous ascorbate reported nausea, hyperacidity or dark stools, against none on SunActive Fe. In 192 children, side effects affected 5% on liposomal SunActive iron and 25% on iron polymaltose. Both trials gave far less iron in the SunActive arm and neither was described as blinded.
Hemoglobin and iron stores in children with low iron
In a 6-month randomized trial of 192 children aged 2 to 12 with low iron, a liposomal SunActive iron product at 1.4 mg/kg a day gave higher hemoglobin (13.32 vs 12.13 g/dL) and ferritin (39.6 vs 25.9 ng/mL) than iron polymaltose at 6 mg/kg. Blinding was not described and the report has internal inconsistencies.
Iron absorption measured against ferrous sulfate
In two isotope studies in 20 women, iron from SunActive Fe in a cereal or yogurt drink was absorbed about as well as ferrous sulfate (3.4% vs 4.1%; 3.9% vs 4.2%). In apple juice it reached 60% of ferrous sulfate, and as a powdered prenatal supplement 22% of a ferrous fumarate tablet. These are absorption markers, not iron status.
Infant development with daily low-dose iron from 4 to 9 months
In a placebo-controlled trial of 221 healthy breastfed infants, about 1 mg/kg a day of this iron form did not change motor, thinking or language scores at 12, 24 or 36 months and did not significantly lower iron deficiency at 12 months. A later secondary report found fewer behavior problems at age 3.
Mood and tiredness after exercise in athletes with normal iron
In a 4-week placebo-controlled trial of 95 non-anemic athletes, 3.6 mg a day of SunActive Fe lowered overall mood disturbance and post-exercise tiredness in the men, while relief from fatigue did not differ and the women showed no difference. Hemoglobin did not change. The maker part-funded the trial and employed most authors.
Iron powder designed to stay dispersed in drinks and foods
Very fine ferric pyrophosphate particles are coated with an emulsifier so they stay suspended in liquids instead of settling. The maker states the powder has no iron taste and suits beverages, dairy foods and supplements, but warns it can discolor products that also contain vitamin C, B12, fruit juice or polyphenol-rich colorants.
Mechanism of action
Very small particles kept apart by an emulsifier coating
Ferric pyrophosphate does not dissolve in water. SunActive Fe grinds it to particles averaging about 0.3 micrometers in the first human study and coats them with an emulsifier, listed as sunflower lecithin in the Fe-P80LK grade, so they stay dispersed rather than clumping. More surface area is the proposed reason for better absorption than standard ferric pyrophosphate.
Proposed uptake through gut immune cells (lab and animal work)
In cell models and rats, SunActive Fe was taken up and moved across the gut lining more than uncoated ferric pyrophosphate, mainly through microfold (M) cells, and in Taiyo Kagaku's rat study it restored hemoglobin efficiently. The maker markets it as endosomal iron, an uptake route that has not been tested in people.
Absorption still depends on iron status and the meal
In 15 women, absorption from SunActive Fe rose as ferritin fell, as it does for soluble iron. Absorption varied with the food it was in, from close to ferrous sulfate in cereal and yogurt to lower in apple juice and in a powdered supplement. The maker notes that polyphenols, phytic acid, fiber and calcium reduce its absorption.
Clinical trials
Randomized, open-label, active-controlled, multicenter 4-week trial (CTRI/2024/07/070773). One daily SunActive Fe tablet (27 mg iron with vitamin C, vitamin B12, folic acid and glycine) vs one ferrous ascorbate tablet (100 mg iron with folic acid); primary aim was non-inferiority for hemoglobin change. Material and testing costs were paid by Generex Pharmassist, which employed two co-authors; no Taiyo Kagaku authors (Patki et al. 2025, Sci Rep)
111 second-trimester pregnant women in India aged 20 to 35, hemoglobin 9 to 10.5 g/dL and ferritin below 15 mcg/L; 108 completed.
Hemoglobin rose 2.63 vs 2.62 g/dL (between-group P = 0.973), meeting the non-inferiority margin; ferritin, reticulocyte hemoglobin and FACIT-Fatigue scores (14.1% vs 14.2%) also did not differ. Adverse events occurred in 6 of 54 on ferrous ascorbate and none on SunActive Fe (P = 0.028). The arms differed in iron dose and added vitamins, and the trial was open-label and 4 weeks long.
Open-label, single-arm 90-day study (CTRI/2022/11/047376) of one daily 30 mg iron SunActive Fe tablet with vitamin C, vitamin B12, folic acid and glycine; run by a contract research organization, with two authors later listed as Generex Pharmassist staff (Srivastav et al. 2024, Cureus)
27 second-trimester pregnant women in India with hemoglobin 9 to 10.5 g/dL and ferritin 10 to 15 mcg/L.
Hemoglobin rose from 9.87 g/dL by 2.86 g/dL at day 30 and 2.41 g/dL at day 90; ferritin rose by 81.3 mcg/L by day 90; FACIT-Fatigue scores improved 41.1% from baseline. Two mild adverse events were judged unrelated. Without a control group, the changes cannot be separated from those expected with any iron.
Randomized two-arm trial (PACTR 202408587364621) at one Egyptian hospital in children with hemoglobin below 11 g/dL and serum ferritin 7.5 to 13 ng/mL: a liposomal SunActive iron product (Fortiferrum) at 1.4 mg/kg a day vs iron polymaltose complex at 6 mg/kg a day for 6 months; primary outcome was hematologic and iron-profile change at 1 month; blinding not described; no specific funding (Bahbah et al. 2025, Clin Exp Pediatr)
192 children aged 2 to 12 with low hemoglobin and depleted stores (entry criteria above); all completed.
Hemoglobin was higher with SunActive at 1 month (12.12 vs 11.9 g/dL) and 6 months (13.32 vs 12.13 g/dL), as were stores at 6 months (serum level 39.62 vs 25.86 ng/mL), all P < 0.001; weight z scores rose more. Side effects affected 5 of 96 vs 24 of 96 children (P < 0.001), although the methods text says none occurred on SunActive.
Two stable-isotope studies in adult women, each test meal fortified with 5 mg iron as SunActive Fe (average particle size 0.3 micrometers, with emulsifiers) or ferrous sulfate; two co-authors were Taiyo Kagaku staff (Fidler et al. 2004, Br J Nutr)
20 healthy adult volunteers in Switzerland, 10 per study (see design).
Absorption did not differ significantly: 3.4% vs 4.1% from infant cereal (P = 0.24) and 3.9% vs 4.2% from a yogurt drink (P = 0.72). Single test meals measure absorption, not changes in body stores.
Stable-isotope comparison in women of SunActive Fe and ferrous sulfate added to pure apple juice, measured by red cell isotope incorporation 14 days later; stores assessed as serum ferritin; funding not described in the abstract (Roe et al. 2009, Eur J Nutr)
15 volunteers in the UK (see design) with relatively low body stores.
Absorption from SunActive Fe was significantly lower than from ferrous sulfate (5.5% vs 9.1%), a relative bioavailability of 0.6. Absorption from both forms was higher in volunteers with lower stores (for SunActive Fe, r = -0.76).
Randomized crossover study (NCT00789490) of serum iron over 8 hours after a powdered supplement with 30 mg iron as SunActive Fe vs a prenatal tablet with 27 mg iron as ferrous fumarate; funded by the H.J. Heinz Foundation (Hartman-Craven et al. 2009, BMC Pregnancy Childbirth)
18 healthy expectant mothers at 24 to 32 weeks of gestation in Canada; about half had depleted stores at baseline.
The rise in serum levels over 8 hours was significantly smaller after the SunActive Fe powder (P = 0.003), a relative bioavailability of 0.22 vs the tablet; folic acid absorption did not differ. The authors described the result as unexpected and contrary to earlier reports.
Randomized, double-blind, placebo-controlled trial (NCT02242188) in Poland and Sweden of micronized microencapsulated ferric pyrophosphate, about 1 mg/kg a day (7, 10 or 15 mg), vs maltodextrin; the protocol names the product as Actiferol (SunActive Fe); product donated by Sequoia Health and Science and Polski Lek; primary outcome Bayley-III motor score at 12 months (Svensson et al. 2024, JAMA Pediatr)
221 healthy, term, non-anemic, exclusively or predominantly breastfed infants; 200 analyzed at 12 months.
No effect on motor (difference -1.07 points, 95% CI -4.69 to 2.55), cognitive or language scores at 12 months, and no differences at 24 or 36 months; deficiency at 12 months was not significantly reduced (RR 0.46, 95% CI 0.16 to 1.30). In a 2026 secondary report, 133 children assessed at 3 years had lower externalizing behavior scores in the supplement group (45.6 vs 48.6, adjusted P = 0.006).
Double-blind, randomized, placebo-controlled 4-week trial at two Japanese universities of one daily sachet of SunActive Fe granules (3.6 mg) vs dextrin, with men (site 1) and women (site 2, hot-yoga practitioners) analyzed separately; no primary outcome or registry number stated; partly funded by Taiyo Kagaku, and four of seven authors work for Taiyo Kagaku or Taiyo International (Kapoor et al. 2023, Contemp Clin Trials Commun)
95 healthy non-anemic athletes at two sites: 51 men (soccer and futsal players) and 44 hot-yoga exercisers; 91 completed.
In men, total mood disturbance fell more than on placebo (P = 0.016) and tiredness after exercise differed in one repeated-measures model (P = 0.047), but relief from fatigue did not differ. In the hot-yoga group, no fatigue or exercise measure differed between groups. Hemoglobin did not differ in either sex.