Objectives: There is an increasing body of literature documenting the efficacy of micronutrients (vitamins and minerals) interventions for the treatment of psychiatric problems in the short term; however, long-term safety is largely unexplored. The goal of this observational study was to investigate the safety of two commercially available broad-spectrum micronutrient formulas (EMPowerplus and Daily Essential Nutrients) given at doses above the Recommended Dietary Allowances for the long-term treatment of individuals with psychiatric symptoms. Design: Participants on long-term treatment with micronutrients (medication-free) for psychiatric problems (attention-deficit hyperactivity disorder [ADHD, n = 21], anxiety/depression [n = 13]) were identified from ongoing research studies and the community through purchasing records. Seventeen children and 17 adults had blood tests to assess their full blood count, coagulation profile, liver and kidney function, fasting glucose, iron studies, key nutrients, and prolactin. Questionnaires assessed psychological/psychiatric functioning. Seventeen of the participants had completed the same measures pretreatment. Results: The average length of consuming micronutrients was 2.66 years (standard deviation = 2.86). Excluding B 12 (which was elevated for almost all participants), 94.6% of all blood test results were within the test reference ranges. One participant was diagnosed with hemochromatosis based on iron studies. No other clinically relevant adverse changes in blood results were identified pre-and post-treatment. No clinically significant adverse effects were reported. Post-treatment psychometrics identified that 85% of the participants were in nonclinical ranges for measures of ADHD, depression, anxiety, and stress. Conclusions: We report preliminary evidence for the safety of long-term commercially available micronutrients, although questions remain. Overall, the substantial psychiatric benefits observed appear to outweigh the minimal observed risks in these participants. Screening for potential medical problems is recommended before initiating treatment. Long-term pharmacovigilance monitoring is required to ascertain any rare but significant adverse events.