Background: Advanced intermittent hypoxia-normoxia KZ-001 (manufactured in Japan under the Japanese Wellness Science and Technology) is a combination of a fine-tuned hypobaric (hypoxia) and hyperbaric (hyperoxia) chamber. It is a new Japanese method that uses both aerospace and high-terrestrial altitude research or training to stimulate the effects of high altitude on the human body, especially hypoxia and hyperoxia. Objectives: This study aimed to test two hypotheses in response to advanced intermittent hypoxianormoxia KZ-001 stratification based on its mechanism of action and to answer the following clinical question: Do patients’ glycated hemoglobin (HbA1c) levels decrease when undergoing advanced intermittent hypoxia-normoxia KZ-001 treatment? Material and methods: This was an observational clinical trial approved by, from January 2019 to August 2020. Outpatients from the endocrine and internal medicine clinics of who met the following criteria were included in the study: clinical diagnosis of type 2 diabetes mellitus (type2DM), ages ≥30 and ≤60 years, currently treated with one or two classes of oral glucose-lowering therapy (given either as separate or combined medications), diabetes duration ≥12 months, no change in diabetes treatment (new treatments or dose change) within the past 3 months, HbA1c level >58 mmol/mol (>7.5%) and ≤110 mmol/mol (≤12.2%), and able and willing to provide informed consent. A total of 100 patients (40 women and 60 men) were recruited. Period of treatment depends on given cases started from 48 to 480 hours seasons. Each treatment session lasted for 50 min thrice with 10-min breaks in between, making sure to drink water during sessions. These were repeated for 12 sessions that lasted for 4 weeks, taking 48 h for three sessions per week. The patients’ HbA1c levels were measured after completing the sessions for 2 days and after one year. Results: The initial HbA1c level (mean ± SD) was 8.30 ± 0.75 and at randomization was 6.27 ± 0.68 using the paired t-test. Significant differences were observed between patients before and after treatment (p = 0.001). The patients were followed up one year after treatment completion through random HbA1c testing (mean ± SD = 6.77 ± 0.8; p = 0.336, with no significant difference), without any change in their treatment regimen or even their lifestyle. Conclusions: Hypobaric/hyperbaric chamber treatment is an adjuvant to the standard therapy in insulin-independent T2DM patients, without replacing and/or delaying medical treatment, with favorable results. Provided that this therapeutic tool is available, it can contribute to decreased amputation rates and reduce the cost of standard treatment, hospitalization, drugs, and use of operating theaters.