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Iron (Supplement)

Used for: Dietary supplementation
Chinese name:

What is Iron for?

Iron is one of the trace minerals like Copper that regulates the body’s physiological functions. It is responsible for oxygen transport as part of hemoglobin in our red blood cells. The recommended daily dietary intake of Iron for adults is 12 mg for men and 20 mg for non-pregnant women. If you are pregnant, the recommended daily dietary intake would be at least 30 mg.


The elemental Iron in different supplemental products is usually ionized into the ferrous form, including ferrous sulfate, ferrous fumarate and ferrous gluconate. Each of these common Iron products contains a different amount of elemental Iron. The conversion is as follows:

  • 300 mg ferrous sulfate = 60 mg elemental Iron
  • 200 mg ferrous fumarate = 65 mg elemental Iron
  • 300 mg ferrous gluconate = 35 mg elemental Iron

Some symptoms of Iron deficiency include anemia, headache, hair loss, laboured breathing upon exertion, fatigue, and pale skin. People who produce less stomach acid, or who take drugs that alter stomach acid, absorb less iron. Pregnant or menstruating women, infants, vegetarians, athletes, and people with bleeding ulcers are all at risk of iron deficiency. Serious iron deficiency may require treatment with injectable Iron. Always speak with your doctor before taking iron since it is important to monitor improvements in your blood tests and taking too much iron can be harmful.

How to use it?

Iron supplements are available in oral dosage forms like tablets and liquid. You should not take Iron supplements with food.


If you are having an Iron deficiency, the usual adult dose is 10-200 mg elemental iron daily either in one dose or two doses. The exact dose will depend on your medical condition, the severity of Iron deficiency, and your age.


If you are pregnant, you are advised to take at least a daily 30 mg elemental Iron to ensure a sufficient Iron intake.


For Iron injection, the amount of iron injected depends on your body weight and the severity of iron deficiency.

What are the side effects of Iron?

The side effects of taking Iron are mainly gastrointestinal, including nausea, constipation and black stools. The side effects of Iron injection are headache, nausea, and low blood pressure.

Who should not take Iron?

  • People who are allergic or sensitive to iron salts or any ingredient of the formulation.
  • Patients with hemochromatosis (iron overload) or hemolytic anemia.

Pharmacist Tips:

Most people should obtain adequate amounts of Iron from a healthy diet. You can obtain Iron from liver, bread, pasta, red meat, poultry, legumes, lentils and vegetables.


Common dosing schedule:
You can take Iron with food to prevent an irritated stomach.

Do not take cereals, dietary fibre, tea, coffee, eggs, milk with Iron.


This schedule is for reference only, adjustments may be made according to individual needs.


Some common medications Iron may interact with:

Please notify your doctor or pharmacist if you are taking the above medication, dosage adjustments might be needed.

Where to buy Iron in Hong Kong?

In Hong Kong, Iron supplements can be purchased without a prescription from any retail outlet in Hong Kong. This includes grocery stores, convenience stores, medicine shops, and pharmacies. It can also be obtained from doctors. Injectable Iron is a prescription drug and requires a prescription from a doctor to be purchased in a pharmacy. It can also be obtained from doctors. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.


For more information about drug names and ingredients, you can visit Hong Kong’s Drug Office at https://www.drugoffice.gov.hk

Need more information?

For detailed information about the use of Iron (Supplement) in children, pregnancy and breastfeeding, and for questions about drug interactions, please check with your pharmacist or doctor.

Disclaimer: our goal is to provide you with the most relevant drug information and common dosage for Hong Kong. This information does not constitute medical advice. For specific treatment recommendations and advice, always discuss with your doctor or pharmacist, and follow the instructions included with your specific medicine.

Brands in Hong Kong
Available dosage
  • 36mg (Capsules)
Drug class
Sub class
Minerals & Electrolytes
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