Iron release from the Lucky Iron Fish®: safety considerations

Asia Pac J Clin Nutr. 2017 Jan;26(1):148-155. doi: 10.6133/apjcn.102015.14.


Background and objectives: The principal objective was to explore in greater detail safety issues with regard to the use of the Lucky Iron Fish® (fish) as a treatment for iron deficiency and iron deficiency anaemia in women in rural Cambodia.

Methods and study design: Experiments were done to determine: (1) purity of the iron in the fish by mass spectroscopy; (2) release of iron and contaminants released during boiling in water using inductive-ly-coupled plasma optical emission spectroscopy; (3) the impact of cooking time, acidity and number of fish in acidified water and two types of Khmer soups; and (4) drinkability of the water after boiling with different num-bers of fish.

Results: The fish is composed primarily of ferrous iron with less than 12% non-ferrous iron. Contaminants were either not detectable or levels were below the acceptable standards set by the World Health Organization. The length of time boiling the fish and the acidity of the water increased iron release but even with 5 fish boiled for 60 minutes, iron levels only approached levels where side effects are observed. Boiling one fish in water did not affect the perception of colour, smell or taste of the water but boiling in water with two or more fish resulted in the water being unpalatable which further limits the potential for iron toxicity from using the fish.

Conclusions: The results suggest that the Lucky Iron Fish™ may be a safe treatment for iron deficiency.

MeSH terms

  • Anemia, Iron-Deficiency / drug therapy*
  • Cambodia
  • Cooking / methods*
  • Dietary Supplements
  • Female
  • Ferrous Compounds / administration & dosage
  • Food Contamination / analysis
  • Food Safety*
  • Hot Temperature
  • Humans
  • Hydrogen-Ion Concentration
  • Iron / administration & dosage*
  • Iron / chemistry
  • Iron / deficiency*
  • Rural Population
  • Taste
  • Time Factors
  • Water


  • Ferrous Compounds
  • Water
  • Iron