Each NPI file in the NPI Registry has been submitted by a practitioner or researcher through the dedicated platform hosted by the NPIS. Each file undergoes review by an independent and integrated scientific committee. This committee invites relevant scientific societies and health authorities to validate the NPI files and/or to oversee the decisions made. Each validated file is then reviewed by a committee of users and professionals. Once labeled NPIS©, the file is translated into at least English and French and integrated into the NPI Registry.

The file contains standardized content supported by scientific studies that align with the NPIS definition of NPI, the expected specifications (Table 2), and the consensual evaluation framework for NPI, known as the NPIS Model. It includes a manual for professionals, an information notice for users, a section on funding options, and an area for anonymous user feedback. This ensures the file remains dynamic and part of a virtuous cycle of continuous improvement for the NPI.

A minimum of one prototypical study, one mechanistic study, two interventional studies, and one implementation study published in a peer-reviewed journal is required for an NPI proposal to be accepted by the expert committee tasked with validating the NPI file and awarding the NPIS© label. Specifically, experts must have evidence to anonymously vote on each criterion of the NPI file proposed to the NPIS by a submitter:

• Described (≥ 1 prototypical study)
• Explainable (≥ 1 mechanistic study)
• Effective (≥ 2 interventional studies)
• Safe (≥ 2 interventional studies)
• Implementable (≥ 1 implementation study in the country)

A professional must understand all the specifics of the NPI, the criteria justifying its use, how to implement its protocol, whom to contact, useful tips, required materials, and any prerequisite training needed.

A scientific validation model for medications has existed since the 1960s, with specific regulations recognized worldwide (e.g., FDA, EMA, ANSM). A similar procedure has recently been implemented for medical devices in Europe. However, until now, no consensual model existed for nutritional, bodily, and psychosocial health services due to confusions between approach, protocol, and technique/ingredient. A participatory, pragmatic, and multidisciplinary consensus work followed international scientific health recommendations to address this for NPI (Ninot et al., 2023).

This work took into account the specificities of NPI, health risks, the balance between internal and external validity, the justification of explanatory mechanisms, ethical considerations in health, and respect for contexts of use. The NPIS Model accelerates research through the harmonization of methodological and ethical expectations in NPI. It also enhances the identification, referencing, transferability, and implementation of NPI for the benefit of user health and safety, improving the quality of training.

Ultimately, the NPIS Model distinguishes between individualized, science-based services aimed at addressing known health issues in Western medicine and occupational practices (lifestyle, art of living, work, sociocultural activity, personal development, pursuit of happiness, spiritual practice, etc.). In this sense, the model does not impede individuals' freedom to choose a particular lifestyle. It aims to address a specific health issue for an individual or a group of people within a limited timeframe and a framework regulated by the health sector. The NPIS Model encourages innovations across all other health sectors, particularly in health organizations and early identification actions for health problems.

NPI are a field in which many amalgamations occur between scientific knowledge and opinion, due to their objective—human health—and their operational mode, which involves immaterial protocols. However, it is essential to learn to distinguish science from research amidst the multiplication of tools and information channels (Klein, 2020), particularly on the subject of NPI. The same communication channels transmit both scientific knowledge and beliefs, opinions, comments... Information of different statuses becomes intertwined. Knowledge can turn into the belief of a particular community, and vice versa.

Research, on the other hand, pertains to questions for which we do not yet have answers. These well-defined questions still have no answer. A researcher works on the subject using various methods and strategies. Research fosters doubt. Scientific societies work to advance research within a specific territory and theme.

Given that NPI are universal health protocols centered on individuals and administered by humans, an international multidisciplinary scientific society needed to be created. This has been achieved since 2021. This society is called the Non-Pharmacological Intervention Society (NPIS).