This is a prospective, randomized, placebo-controlled, double blind, parallel-arm study in a two-staged approach that will assess the effect of two different doses of G-PUR® on enteral lead absorption in healthy adults using a stable lead isotopic tracer (204Pb).

Inclusion Criteria:

1. Healthy male and female subjects
2. Age 18-45 years
3. BMI 19-27 for males and BMI 17-25 for female
4. Blood lead (PbB) concentration < 40 μg/l
5. Serum ferritin concentration within the sex-specific normal range, i.e. ≥ 15 - 150 ng/ml for women and 30 - 400 ng/ml for men
6. Presence of scalp hair with a minimum length of 5 mm and willingness to remove 5 single hairs with hair roots at end of study visit
7. Subject is in good clinical and mental health as established by medical history and physical examination
8. Stable eating habits, within one month before the start of the study
9. Subject agrees to be compliant for study related diet schedule
10. Women of childbearing potential agree to use adequate birth control methods during the study (for all females, negative pregnancy test at screening and at Visit 3 before dosing of IMD is required. Females of childbearing potential must use adequate contraception during the entire study period. Acceptable methods of contraception include: oral contraceptives, intrauterine device, female or male condoms with spermicide, diaphragm with spermicide, contraceptive medication patch, contraceptive medication implant, contraceptive medication injection, abstinence, or surgical sterilization more than 3 months before randomization.
11. Written informed consent

Exclusion Criteria:

1. Pregnancy and breastfeeding
2. Lack of willingness or capacity to co-operate appropriately
3. Regular use of medications or iron supplements in the previous 2 months except intake of contraceptives
4. Planning to shave head during study
5. History of malignancies within the past two years or on current anticancer treatment
6. History of gastrointestinal pathology such as gastritis, gastric ulcers, irritable bowel disease, inflammatory bowel disease, chronic constipation
7. History of diarrhoea within the past 14 days of screening
8. History of gastrointestinal surgery with exception of appendectomy
9. History of chronic autoimmune disease requiring treatment within the past two months of screening
10. Known diabetes mellitus I or II or Hba1c >6.5%
11. Known symptomatic food allergies
12. Any clinically relevant laboratory abnormalities in screening test
13. Alcohol, cigarette or drug abuse
14. Mental condition rendering the subject unable to understand the nature, scope and possible consequences of the study
15. Presence of any condition that impacts compliance with the study procedures
16. Use of any regular medication (prescription or over the counter) for prevention or treatment of any medical condition
17. Use of any investigational or non-registered product (drug or device) within 30 days preceding the first study product administration, or planned use during the study period
18. Employee at the study site, spouse/partner or relative of any study staff (e.g. investigator, sub-investigators, or study nurse) or relationship to the sponsor
19. IMD should not be applied to patients that suffer from aluminium and/or silicon hypersensitivity or in case of renal failure that requires dialysis.