Iron supplements like ferrous sulfate are commonly used to treat iron deficiency anemia. The color of ferrous sulfate pills can vary depending on the formulation, additives, and the dose of elemental iron. Here’s a closer look at the typical colors of ferrous sulfate supplements.
Common Colors of Ferrous Sulfate Pills
Ferrous sulfate pills are available in various strengths, ranging from 50 mg to 300 mg of elemental iron per tablet. The most common colors include:
- Green – Many standard ferrous sulfate tablets are green. This is because they contain blue and yellow dyes.
- Brown – Some ferrous sulfate pills have a brownish hue, often with mottled specks. This is the natural color of iron.
- Red – Some high-dose ferrous sulfate tablets are reddish-brown due to the higher iron content.
- Yellow – Certain timed-release or extended-release ferrous sulfate tablets have a yellow coating.
- Blue – Some ferrous sulfate pills contain blue dyes, giving them a greenish-blue tint.
- Coated – Special coatings and dark encapsulations can give ferrous sulfate pills a gray, black, or metallic hue.
Why Does the Color Vary?
There are a few reasons why ferrous sulfate supplements come in different colors:
- Iron content – Tablets with higher doses of elemental iron tend to be darker in color.
- Dyes – Many ferrous sulfate pills contain artificial colorings like FD&C Blue No. 1 or D&C Yellow No. 10.
- Additives – Additional ingredients like sugars, flavors, or waxes can impact the color.
- Coatings – Special coatings and encapsulations alter the exterior shade.
- Formulation – Different formulations like liquid gels, capsules, and timed-release tablets affect color.
- Brand – Brands use different combinations of dyes, sugars, and coatings which produce unique colors.
Green Ferrous Sulfate Tablets
Green is perhaps the most common color for standard ferrous sulfate tablets. Here’s why they are often green:
- Iron content – Most green tablets contain between 325 mg to 65 mg elemental iron per tablet.
- FD&C dyes – They typically contain a blend of FD&C Blue No. 1 and D&C Yellow No. 10 dyes.
- Additives – Sugars and waxes added during production can give a greenish tinge.
- Brands – Many major brands like Feosol, Fergon, and Slow FE use green dyes.
For example, Feosol tablets contain ferrous sulfate along with colors, waxes, magnesium stearate, and sugars that give them their characteristic green color.
Brown Ferrous Sulfate Pills
Some ferrous sulfate pills have a light brown, tan, or mottled brownish appearance. Here’s why they can be brown:
- Iron content – Brown tablets tend to be lower dose, like 65 mg iron.
- Natural iron color – The natural rust-like color of ferrous sulfate can produce a light brown hue.
- Minimal dyes – They have fewer or no artificial coloring added.
- Timed-release – Extended release coats can give a speckled brown effect.
- Brands – Brands like NovaFerrum, Ircon, and Ferrex use more natural coloring.
For instance, NovaFerrum 125 mg tablets contain ferrous sulfate with no dyes, giving them a naturally brown and spotted look. The extended release coating also contributes to the mottled effect.
Red and Reddish Brown Pills
Some ferrous sulfate pills have a distinctly reddish, rusty, or reddish-brown color. This is typically due to:
- High iron content – Red tablets contain very high iron doses, like 300 mg per pill.
- Natural iron color – The higher iron concentration produces a more intense rust-like tone.
- Minimal dyes – They generally have fewer color additives to let the natural iron color show through.
- Brands – High dose brands like Ferrex 150, Hemocyte, and Fergon tend to use red tones.
For example, Ferrex 150 tablets contain 300 mg of ferrous sulfate, giving them a noticeably reddish-brown appearance from the high iron content with minimal dyes.
Yellow Ferrous Sulfate Supplements
Some ferrous sulfate pills have a pale yellow, yellowish-green, or yellow-coated appearance. A few reasons for this include:
- Timed-release coats – Yellow wax-like coats help control iron release.
- D&C Yellow No. 10 dye – This brighter yellow coloring agent is sometimes added.
- Combination colors – Mixed with blue dye, yellow can produce greenish-yellow hues.
- Brands – Slow FE, Fergon, and MyKidz Iron use yellow coats or dyes.
For example, Slow FE capsules have a yellow wax-like coating that slowly releases the ferrous sulfate inside to help prevent side effects.
Blue Ferrous Sulfate
While less common, some ferrous sulfate pills have a bluish-green tint. Reasons for this include:
- FD&C Blue No. 1 – This blue food coloring is sometimes used.
- Combination with yellow – Together, blue and yellow dyes make greenish-blue hues.
- Brands – Champion and some generic brands produce bluish-green tablets.
For instance, some generic ferrous sulfate tablets contain a higher proportion of FD&C Blue dye along with yellows, giving them a more blue-green appearance.
Coated and Colored Capsules
In addition to pills and tablets, ferrous sulfate also comes in gel caps and coated caplets. These have a different appearance:
- Gel caps – Clear and colored gelatin capsules with liquid fill.
- Dark caps – Opaque dark coatings obscure interior color.
- Metallic sheen – Mineral-containing caps can have a gray, silver or gold tone.
- Brand examples – Products like Hemocyte, Fergon, and Estrostep use dark or metallic capsules.
So in opaque capsules, the ferrous sulfate itself is hidden from view. Only the exterior coloring, texture, and coatings are visible.
Typical Ferrous Sulfate Doses
Ferrous sulfate is available in a range of strengths and doses. The potency typically correlates with the color intensity. Some typical amounts include:
| Dose | Color |
|---|---|
| 50 mg iron | Light green |
| 65 mg iron | Light green or light brown |
| 90 mg iron | Medium green |
| 150 mg iron | Dark green |
| 300 mg iron | Reddish brown |
As shown, ferrous sulfate tablets containing higher amounts of iron generally have a darker, more intense color.
Impact of Formulation on Color
The formulation of ferrous sulfate supplements also influences their final color, including:
- Tablets – Contain dyes, sugars, waxes that modify color.
- Capsules – Opaque capsules obscure interior color.
- Liquids – Form clear, yellow, or brown oral solutions.
- Timed-release – Coatings create a speckled effect.
- Combinations – Added vitamins or herbs impact color.
So while the ferrous sulfate itself is a grayish-brown powder, the formulation with various additives produces the final supplement color.
Impact of Brand on Color
Each supplement brand uses their own unique combination of iron dose, dyes, coatings and additives. This means ferrous sulfate pills will differ in color between brands. Here are some color examples by brand:
| Brand | Color |
|---|---|
| Feosol | Green |
| Slow FE | Yellow-coated |
| Ferrex 150 | Reddish brown |
| NovaFerrum | Light brown |
| MyKidz | Green with yellow coating |
So Ferrex 150 has a distinct rusty color from its high iron content, while Slow FE is identified by its yellow timed-release coating.
Does Color Indicate Iron Absorption?
The color of ferrous sulfate pills generally does not indicate how well the iron will be absorbed. Iron absorption depends more on:
- Dose – Higher doses increase iron availability.
- Formulation – Extended release improves absorption.
- Type of iron – Ferrous sulfate is well-absorbed.
- User factors – Taken on empty stomach improves absorption.
Instead, the color mainly reflects the concentration and type of dyes, coatings, and iron dose rather than absorbability per se. However, in general ferrous sulfate is one of the most efficiently absorbed forms of iron.
Conclusion
In summary, ferrous sulfate pills come in a rainbow of colors including green, brown, red, yellow, and sometimes blue. The specific color results from the iron dose, any added dyes or coatings, and the brand. While the hue does not necessarily indicate absorption, ferrous sulfate itself is typically well-absorbed compared to other iron compounds. So pay attention to the dose on the label rather than making assumptions based solely on pill color.