Iron

Iron reference formula at an example 18 mg of elemental iron per serving, developed as a capsule or tablet, with the amount set by the brand.

Iron is a reference formula for brands building a single-ingredient iron product around example amounts of 18 to 65 mg of elemental iron per serving, with 18 mg shown as the example. Iron is the only active ingredient, so the development work centers on the choice of iron salt, the salt weight that carries the elemental iron, and the tolerability of the finished unit.

Capsule is the lead format because a chelated iron salt at 18 mg of iron fits a small fill, while the tablet carries the same active with a coating that limits taste and staining. The amount is a starting point, and the brand and its market review set the final tier.

Ingredient Composition

IngredientPer ServingRaw Material FormAlternative Form (same amount of active)
Iron18 mg (example amount)Ferrous bisglycinate, specified on elemental iron content; 18 mg iron per servingFerrous fumarate or ferrous sulfate, with the input recalculated to 18 mg of elemental iron

Amounts are stated as mg of elemental iron (Fe, 55.84 g/mol; PubChem CID 23925). Iron content by weight follows from the anhydrous molecular weight of each salt: ferrous bisglycinate 27.4% (CID 9837124, 203.96 g/mol), ferrous fumarate 32.9% (CID 6433164, 169.90 g/mol) and ferrous sulfate 36.8% (CID 24393, 151.91 g/mol). Hydrate state, such as ferrous sulfate heptahydrate, and assay of the purchased salt are set with the supplier.

Intended Benefits & Formula Rationale

This formula is designed for products positioned around daily iron intake and iron nutrition. Iron is included as the only active so that the salt, the amount and the unit can be set without interaction with other actives.

Intended Benefit DirectionKey IngredientsFormulation Rationale
Daily iron intakeIronIncluded because iron deficiency is one of the leading contributors to the global burden of disease and particularly affects children and premenopausal women [1]. Evidence: Referenced
Iron status nutritionIronA review reports that oral iron supplementation is usually efficacious in correcting iron-deficiency anemia and replenishing iron stores, and that it causes gastrointestinal side effects that reduce compliance [2]. Evidence: Referenced

The amount is an example that a brand moves up or down for its market. The Lancet review notes that high-dose oral iron limits its own absorption efficiency through hepcidin [1], so the amount and the schedule on the label are decisions for the brand and its market review.

Available Formats

The iron reference formula is built for a capsule version and a tablet version; counts per serving are design choices that the brand can adjust.

FormatUnitPer ServingPack SizeOther Ingredients (typical)Suitability
Capsule1 capsule18 mg iron60 or 90 capsulesCellulose, hypromellose shell, magnesium stearateLead format; chelate in a small fill
Tablet1 tablet18 mg iron60 or 100 tabletsCellulose, binder, disintegrant, lubricant, coatingCoated unit that limits taste and staining

Raw Material Input & Fill (Design Estimate)

Design estimates. The input is the iron amount divided by the iron content of the salt at an assumed 100% assay: ferrous bisglycinate at 27.4% gives about 65.7 mg of salt for 18 mg of iron, against about 54.8 mg of ferrous fumarate and 49.0 mg of ferrous sulfate.

FormatRaw Material Input per UnitDesign FillBalance for ExcipientsVerification Before Scale-Up
Capsule65.7 mg bisglycinate200 mg per capsule134.3 mgBlend uniformity, fill weight variation, content assay of iron
Tablet65.7 mg bisglycinate250 mg tablet weight184.3 mgHardness, disintegration, coating integrity, content assay of iron

Liquid and gummy versions are separate projects, because dissolved iron brings metallic taste, color change and oxidation that need their own stability work.

Formulation Considerations

Salt choice and iron yield. The salt weight per 18 mg of iron runs from about 49 mg for ferrous sulfate to about 66 mg for ferrous bisglycinate. The lead salt in this design is the chelate, and the salt is fixed with the supplier together with its assay and its water content.
Tolerability. Oral iron causes gastrointestinal side effects that reduce compliance [2]. A chelated salt, a coated tablet or a capsule shell is how the format addresses this, and the amount tier is the other lever.
Absorption and dose. Hepcidin upregulation after oral iron limits the absorption efficiency of high-dose oral iron [1]. Higher tiers therefore do not scale in a straight line, and the tier and the dosing schedule are written into the label review.
Staining and interaction in blends. Iron salts can discolor tablets and interact with vitamin C or calcium in a blend. Each additional active is checked for color and stability before it is added to the reference formula.

Customization Options

Brands adjust the amount per serving, the iron salt, the format and the coating.

ParameterRangeNote
Amount per serving18, 25, 27 or 65 mg ironExamples for the brand; each tier is checked against the limit of the sales market
Iron saltBisglycinate, fumarate or sulfateIron percent differs by salt; input recalculated from the supplier assay
FormatCapsule or tabletLiquid and gummy are separate projects
CoatingNone, film coat or entericSets taste, staining and release behavior of the tablet
Add-onsVitamin C, folate, vitamin B12A second active reshapes the unit weight and the color and stability checks

The pilot run confirms capsule fill weight and blend uniformity of the iron salt, tablet color and coating integrity, and the content assay of elemental iron in the first units against the labeled amount.

Technical Status & Data Sources

ItemStatusDetails
Reference formulaNIH DSLDThe ingredient and amount come from a labeled product in the NIH DSLD (18 mg on the label of CF000568; example DSLD labels 3598, 231194, 242994). The label names the ingredient as iron; ferrous bisglycinate is set as the form.
SpecificationSet in formulationFerrous bisglycinate, 18 mg elemental iron per serving; assay, water content and heavy-metal limits and method are fixed with the supplier. Unit size, fill weight and stability are set in formulation.
Data sourceNIH DSLDDSLD v9.4.0, downloaded 2026-01-10: 50,824 reference formulas merged from on-market labels with complete ingredient amounts. Counts show how labels are distributed.
Market reviewPer marketDose limits, labeling and claims are reviewed for each sales market before a finished product is developed.
ReferencesSources[1] Pasricha SR, Tye-Din J, Muckenthaler MU, et al. Iron deficiency. Lancet. 2021;397(10270):233-248. DOI32594-0) · PubMed<br>[2] Pantopoulos K. Oral iron supplementation: new formulations, old questions. Haematologica. 2024;109(9):2790-2801. DOI · PubMed

Related products

OEM/ODM Development Inquiry

Essencefield supports custom supplement formulation and OEM/ODM development, including ingredient selection, dosage adjustments, delivery formats, flavors, packaging, and commercial supply. Submit your project requirements below to explore customization options, sample development, and manufacturing solutions tailored to your brand and target market.