When developing a light therapy device, manufacturers must demonstrate that the product is safe and performs as intended. One of the key questions in this process is how that evidence is generated. Should a company conduct its own clinical investigation or can it rely on existing scientific literature?

Both approaches are valid under certain conditions, but they serve different purposes and carry different regulatory implications. Understanding the distinction helps brands choose the most efficient and defensible evidence strategy.

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What Is a Clinical Investigation?

A clinical investigation is a structured study conducted on human subjects to evaluate a specific device. It is designed to collect device-specific data under controlled conditions.

Clinical investigations are typically required when:

• the device is novel or significantly different from existing products
• existing literature does not sufficiently support the intended claims
• higher-risk classification applies
• regulators request direct clinical data

For light therapy devices, clinical investigations can provide strong, targeted evidence but they also require time, ethical approvals and significant investment.

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What Is Literature-Based Evidence?

Literature-based evidence relies on existing peer-reviewed studies, clinical data and scientific consensus relevant to the device’s technology, mechanism of action and intended use.

This approach is often appropriate when:

• the technology is well established
• the device is similar to existing products
• claims align closely with published evidence
• risks are well understood

In light therapy, photobiomodulation mechanisms and wavelength-specific effects are widely documented, making literature-based evidence a common and accepted component of clinical evaluation.

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How Regulators View the Difference

Under the European MDR, manufacturers must perform a clinical evaluation that assesses all available clinical data. This evaluation may be based on literature, clinical investigations, or a combination of both.

The FDA follows a similar principle: if existing evidence sufficiently demonstrates safety and effectiveness for the intended use, new clinical studies may not be required. However, gaps in evidence or novel claims often trigger requests for additional data.

In both systems, the key question is not which method is used, but whether the evidence is sufficient, relevant and proportionate to the risk and claims.

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Choosing the Right Evidence Strategy

Deciding between a clinical investigation and literature-based evidence depends on:

• device novelty and technological differences
• risk classification
• strength and relevance of existing literature
• scope of intended claims

Many successful light therapy devices use a hybrid approach, combining established scientific literature with targeted testing or post-market clinical follow-up to strengthen their evidence base over time.

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Evidence Strategy in a Maturing Field

As light therapy becomes more widely adopted, regulators are expecting greater clarity in how evidence supports claims. Simply citing general photobiomodulation research is no longer sufficient if a device introduces new features, protocols, or use cases.

At Light Tree Ventures, evidence strategy is considered early in the development process. Devices are developed and manufactured within ISO 13485-certified quality systems, with regulatory and clinical expertise guiding the balance between literature-based justification and the need for device-specific investigations.

This ensures light therapy products are supported by appropriate, defensible clinical evidence, aligned with both MDR and FDA expectations.

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Final Thoughts

Clinical investigations and literature-based evidence are not opposing options, they are complementary tools. The right balance depends on the device, its claims and its risk profile.

Brands that define their evidence strategy early avoid unnecessary studies, reduce regulatory uncertainty and build stronger, more credible products.

Because in regulated markets, approval depends not only on innovation, but on how well that innovation is proven.

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References

• European Commission – MDR Clinical Evaluation Requirements (MEDDEV 2.7/1 rev. 4)
  https://ec.europa.eu/docsroom/documents/17522
• International Medical Device Regulators Forum (IMDRF) – Clinical Evidence and Evaluation
  https://www.imdrf.org/documents/clinical-evaluation
• Hamblin, M.R. (2017). Photobiomodulation or Low-Level Laser Therapy.
  Journal of Biophotonics
  https://onlinelibrary.wiley.com/doi/10.1002/jbio.201700113

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