A gentler, well-absorbed form of iron that reliably corrects a confirmed iron shortfall while causing fewer digestive problems than older iron salts. Most valuable at modest doses when deficiency is genuine. Because the body cannot remove excess iron, taking it without a confirmed need offers no benefit and risks harmful buildup. (Full Review)

Protocol

Standard Dose

24–30 mg

Elemental iron once daily; lower than the 60–100+ mg given as ferrous sulfate

Timing

Single morning dose

Hepcidin is lower and absorption more favorable; separates iron from evening calcium

Frequency

Daily or alternate-day

A single every-other-day dose lowers hepcidin and raises fractional absorption

Time to effect

Hemoglobin

4–8 weeks

Blood count rises to correct anemia

Ferritin repletion

3–6 months

Full iron-store refill with consistent dosing

Reticulocytes

~1 week

Young red blood cells rise, the earliest response sign

Benefits

High: Corrects iron deficiency and iron-deficiency anemia; superior gastrointestinal tolerability

Medium: Dose-sparing efficacy at lower elemental iron; replenishes iron stores; better absorption despite dietary inhibitors

Low: Reduced fatigue and improved exercise capacity in non-anemic iron deficiency; symptom relief in iron-related restless legs syndrome

Speculative: Cognitive and mood support from correcting deficiency; immune function support

Contraindications

Hereditary hemochromatosis or other iron overload

Transfusion-dependent or non-iron-deficiency anemias (thalassemia, sideroblastic anemia)

No confirmed low iron status

Ferritin persistently above ~200–300 ng/mL or transferrin saturation above ~45%

Key Interactions

Reduces absorption of levothyroxine, levodopa, methyldopa, bisphosphonates, mycophenolate, tetracyclines (doxycycline), fluoroquinolones (ciprofloxacin, levofloxacin)

Antacids, proton pump inhibitors (omeprazole), H2 blockers (famotidine) reduce iron absorption

Calcium, zinc, magnesium, copper compete for absorption; polyphenols (green tea extract, turmeric) bind iron

Any additional iron source (second supplement, fortified foods, multivitamin) is additive toward overload

Vitamin C enhances absorption; folate and vitamin B12 complementary in mixed-cause anemia

Risk & Side Effects

High: Gastrointestinal side effects; iron overload in genetically susceptible or over-supplementing individuals; acute overdose toxicity

Medium: Oxidative stress and harm when iron is not deficient; reduced absorption of other essential minerals

Low: Gut microbiome shifts and enteric pathogen growth; tooth staining with liquid formulations

Speculative: Long-term iron accumulation and chronic disease

Monitoring

Marker	Target	Why
Ferritin	~50–100 ng/mL	Best marker of iron stores; guides start and stop
Transferrin saturation (TSAT)	~25–45%	Reflects iron available for red-cell production
Hemoglobin (Hb)	≈12–15.5 g/dL women, ≈13.5–17.5 g/dL men	Confirms correction of anemia
Total iron-binding capacity (TIBC)	~250–370 µg/dL	Rises in deficiency, falls in overload
Serum iron	~60–150 µg/dL	Component of TSAT; shows circulating iron
C-reactive protein (CRP)	< 1 mg/L	Detects inflammation that distorts ferritin

Cadence: Hemoglobin and reticulocytes at ~4 weeks; ferritin every 3 months until replete; then every 6–12 months with ongoing losses

Qualitative Assessment

Energy levels and reduced fatigue
Exercise tolerance and endurance
Cognitive clarity and concentration
Resolution of restless legs symptoms, cold intolerance, hair shedding, or unusual cravings (pica)

Ferrous Bisglycinate for Health & Longevity

Protocol

Benefits

Risk & Side Effects

Monitoring

Qualitative Assessment