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Feasibility, Tolerability and Adherence of Alternate-Day Ferrous Sulfate (Duroferon) in Adolescent Girls With Iron Deficiency

Registered drug
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What is this trial about?

A plain-language summary of the goals, design and what participants do

The study focuses on iron deficiency that commonly occurs in adolescent girls, a condition where the body does not have enough iron to make healthy red blood cells. Participants will receive an oral tablet taken every other day that contains ferrous sulfate, marketed as Duroferon, while a matching placebo tablet will be used for comparison.

The purpose of the trial is to assess how practical and well‑tolerated the alternate‑day iron supplement is, how consistently participants can follow the dosing schedule, and how accurately the screening tool IRON-5 can identify iron deficiency.

During the study, each girl will take the assigned tablet on alternate days for several weeks and will attend a few clinic visits where blood samples are drawn to check iron levels and related nutrients. She will also complete brief questionnaires about diet, menstrual patterns, fatigue and overall well‑being. All information collected will help determine the safety and ease of use of the supplement and the performance of the screening tool.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Baseline screening

    You will attend an initial visit where a short health questionnaire is completed and a small blood sample is taken to confirm iron deficiency.

    The blood test measures ferritin, haemoglobin and other routine values to determine eligibility for the study.

  2. Step 2

    Randomisation and receipt of study medication

    After eligibility is confirmed, you are randomly assigned to receive either duroferon (a tablet containing 100 mg of ferrous sulfate) or a matching placebo tablet.

    The tablets are supplied in a bottle labeled with your participant number and instructions for use.

  3. Step 3

    Start of alternate‑day dosing

    You begin taking one tablet by mouth every other day. For example, you might take the tablet on monday, skip tuesday, take it on wednesday, and so on.

    Each tablet is a modified‑release form, meaning the iron is released slowly after swallowing.

    The dosage of 100 mg of ferrous sulfate is taken each time you take a tablet.

  4. Step 4

    Maintaining the dosing schedule and recording intake

    You keep a simple diary in which you mark each day you take the tablet and any side effects you notice, such as stomach upset or constipation.

    The diary helps study staff assess how well the regimen is tolerated and whether the dosing schedule is followed.

  5. Step 5

    Mid‑study follow‑up visit

    Around the middle of the trial period, you return for a follow‑up visit.

    Another small blood sample is taken to check changes in ferritin and haemoglobin.

    You may be asked to complete a short questionnaire about fatigue, quality of life and any menstrual symptoms.

  6. Step 6

    Final assessment and study completion

    At the end of the study, you attend a final visit where a blood sample is drawn to evaluate the overall change in iron status.

    The final questionnaire repeats the earlier fatigue and quality‑of‑life items.

    After this visit the study medication is discontinued and the study concludes for you.

Who can join the trial?

6 criteria

  • Student at Polhemskolan, Lund
  • Age 15 years or older
  • Post‑menarcheal – meaning she has begun having menstrual periods
  • Written informed consent from the participant – a signed form showing she understands the study and agrees to join
  • Written informed consent from a legal guardian if the participant is younger than 18 years – a parent or guardian must also sign
  • Serum ferritin less than 30 µg/L – a blood test result showing low iron storage in the body

Who cannot join the trial?

9 criteria

  • Pregnancy – being pregnant at any time while the study is being conducted.
  • Chronic inflammatory disease – long‑lasting conditions that cause ongoing inflammation, such as rheumatoid arthritis (joint inflammation) or Crohn’s disease (inflammation of the digestive tract).
  • Acute infection – a recent, short‑term infection like tonsillitis (sore throat) or a urinary tract infection (bladder infection).
  • CRP >10 mg/L – a blood test called C‑reactive protein shows a level higher than 10, which means there is significant inflammation in the body.
  • Current iron supplementation – taking iron tablets or drops (multivitamins that contain only a small amount of iron are allowed, but regular iron pills are not).
  • Anemia – having low hemoglobin levels (less than 110 g/L for girls under 18 years old or less than 117 g/L for those 18 or older), which means the blood cannot carry enough oxygen.
  • Iron overload – having too much iron stored in the body, shown by a serum ferritin level higher than 150 µg/L (ferritin is a protein that stores iron).
  • Clinically significant vitamin B12 deficiency – very low vitamin B12 levels (less than 150 pmol/L) that need immediate medical attention, because vitamin B12 is important for nerve and blood health.
  • Use of medication that interferes with iron absorption – taking medicines regularly (at least three times a week) that can block iron from being absorbed, such as fluoroquinolones or tetracyclines (certain antibiotics), bisphosphonates (bone drugs), levodopa (used for Parkinson’s disease), methyldopa (blood pressure medication), or antacids that contain aluminum or magnesium.
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Investigated drugs

  • Duroferon

    is a tablet that contains ferrous sulfate, a type of iron. It is taken by mouth and is used to increase the amount of iron in the body. In this study the tablet is given every other day to see if it is easy for teenage girls to take, if they stick with the schedule, and whether it improves their iron levels.

  • Iron Smart

    is an educational and support program that helps participants learn about iron deficiency and how to manage it. It provides information on iron‑rich foods, reminders to take the iron tablet, and encouragement to follow the study plan. All girls in the trial receive Iron Smart, so researchers can see how the iron tablet works when combined with this guidance.

What is already known about the treatment

Duroferon depottabletter - It is taken by mouth as a modified‑release tablet, delivering 100 mg of ferrous sulfate on alternate days. Ferrous sulfate is a well‑known iron supplement that has been used for many years and is extensively described in medical literature. It is mainly used to treat iron‑deficiency anemia, especially in adolescent girls and women who need extra iron. The iron from the tablet is absorbed in the intestines, becomes part of hemoglobin, and helps red blood cells carry oxygen; it belongs to the class of iron salts, a type of nutritional supplement.

Investigated diseases

Iron deficiency - A condition in which the body does not have enough iron to meet its needs. It often begins with low iron stores, reflected by reduced ferritin levels. As the shortage continues, the amount of iron available for making hemoglobin may fall, leading to lower blood iron measures. This can cause symptoms such as tiredness and reduced exercise capacity. In adolescents, the condition may develop gradually due to rapid growth, menstrual blood loss, or inadequate dietary intake. Without sufficient iron, the body’s ability to transport oxygen efficiently can become increasingly limited.
Trial detailsLast updated 9 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2025-522498-12-00Estimated enrolment279 patientsSponsorRegion Skane

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