Is distilled water good or bad?
Executive summary
Distilled water is chemically very pure and generally safe to drink for most healthy adults, but it lacks minerals like calcium and magnesium that appear in other water sources and that some studies link to health benefits, so long-term exclusive use may carry risks without dietary compensation [1][2]. Public-health authorities and clinicians often advise that distilled water is acceptable if a balanced diet supplies necessary minerals, while some industry and advocacy pieces emphasize risks or benefits depending on their agenda [3][4].
1. What distilled water is and what it removes
Distilled water is produced by boiling water into vapor and condensing it, a process that removes bacteria, protozoa, viruses and dissolved inorganic contaminants such as lead, arsenic, nitrates and sulfate, leaving a demineralized product [1][4]. That high level of contaminant removal is why distilled water is used in medical devices, laboratory settings and some industrial applications where “pure” water is required [4][5].
2. Hydration and short‑term safety — generally fine
Multiple consumer‑health outlets report that distilled water hydrates like other waters and is safe in the short term for the average person, and can be a calorie‑free replacement for sugary drinks [1][6]. Clinical caveats are narrowly focused: distilled water does not supply electrolytes lost during severe dehydration from vomiting or diarrhea, where oral rehydration solutions are recommended instead [7].
3. The mineral argument — what the evidence and agencies say
A recurring theme in scientific and public health coverage is that drinking water contributes some calcium and magnesium to the diet, and epidemiological studies have linked low mineral levels in drinking water to fatigue, muscle cramps and — in some analyses — greater cardiovascular risk, so habitual consumption of demineralized water without dietary compensation could matter over the long term [2][3]. WHO reviews and consumer health outlets caution that the absence of minerals may alter nutrient balance, and they advise ensuring minerals come from food if one drinks distilled water regularly [3][8].
4. Claims of harm and industry or sensational sources
A number of blogs and vendors frame distilled water as actively harmful — alleging tooth decay, leaching of body minerals, or bone loss — but those assertions often overreach the evidence and sometimes serve commercial agendas (e.g., companies selling remineralizing filters or alkaline ionizers) [9][10]. Independent warnings about storage and leaching from plastics are credible: demineralized water can more readily dissolve materials from containers, so glass storage is safer than some plastics [5].
5. Where distilled water can be preferable
Distilled water can be a clear advantage when source water is contaminated with pathogens or heavy metals, or for people on sodium‑restricted diets since it contains virtually no dissolved sodium, and for specific uses such as CPAP machines, steam irons, and laboratory work where mineral deposits are problematic [4][8]. In those contexts, the benefits of removing contaminants or minerals outweigh the lack of trace electrolytes [4].
6. Practical guidance and the bottom line
For most healthy adults who eat a balanced diet, occasional or even regular consumption of distilled water is unlikely to cause harm, but exclusive lifelong reliance on distilled water without monitoring dietary mineral intake could increase the risk of subtle deficiencies or electrolyte imbalance, so consultation with a healthcare professional is sensible for vulnerable groups such as infants, pregnant people, older adults, or those with chronic illnesses [3][7][2]. Where possible, choose commercially produced distilled water from potable sources or use glass storage and consider remineralization or dietary adjustments if distilled water is the main beverage [8][5].