Stem Cell Activation & Photobiomodulation: What the Science Shows

What is photobiomodulation?

Photobiomodulation (PBM) is the use of specific light parameters to influence biological activity. It is also referred to in the literature as low-level laser therapy or low-level light therapy. The central idea is that light, delivered at the right wavelength and dose, can act as a biological stimulus rather than a source of heat or damage.

Published research describes several mechanisms through which PBM may act on cells, including cellular signaling, mitochondrial function, adenosine triphosphate (ATP) production, reactive oxygen species, nitric oxide, and downstream biological signaling pathways. These mechanisms are the subject of ongoing laboratory and clinical study.

A key point, often overlooked, is that biological responses to light depend on factors such as wavelength, irradiance, dose, exposure duration, tissue type and cell type. Different parameters can produce different, and sometimes opposite, effects. Not all forms of light exposure produce the same biological effects, and a result observed under one set of conditions cannot be assumed to apply to a different device or protocol. For a broader overview of how this technology is applied in wearable form, see our page on LifeWave light technology.

What does photobiomodulation have to do with stem cells?

Researchers have investigated the effects of photobiomodulation on several types of stem and progenitor cells. The published literature reports effects on:

• proliferation
• migration
• differentiation
• mitochondrial activity
• cellular signaling
• tissue-regenerative processes
• paracrine and secretome activity

It is important to be precise about the kind of evidence this represents. Much of it is laboratory, cell-culture or preclinical research. Reviews of the field note that parameters such as wavelength, dose and cell source change the outcome, and that translating these findings into consistent clinical results requires further study.

The 2025 World Association for Photobiomodulation Therapy (WALT) position paper on photobiomodulation and stem cells reviews this body of work directly. The authors identify a substantial need for additional clinical research before laboratory findings can be translated into reliable clinical guidance.

Is photobiomodulation the same as stem cell therapy?

Conventional stem-cell therapies involve administering, transplanting or otherwise using cells. Photobiomodulation uses light as a biological stimulus. These are fundamentally different approaches, and the distinction matters.

What is GHK-Cu?

GHK is the naturally occurring tripeptide glycyl-L-histidyl-L-lysine, first isolated from human plasma. It can bind copper to form GHK-Cu (also called copper tripeptide-1), and the two forms exist in balance in the body. GHK-Cu has been studied for decades, most extensively by the biochemist Loren Pickart and colleagues.

Published, peer-reviewed research reports that GHK and GHK-Cu are involved in:

• cellular signaling
• tissue remodeling
• extracellular matrix regulation
• collagen-related processes
• repair biology

This literature is drawn from primary peer-reviewed sources, including work in the Journal of Biomaterials Science, FEBS Letters, BioMed Research International and Brain Sciences.

Where does LifeWave X39 fit into this?

LifeWave X39 is a wearable, non-transdermal patch. The manufacturer describes it as a photobiomodulation device that reflects specific wavelengths of light at the skin. It does not deliver drugs, chemicals or cells into the body. You can browse the full lineup on our LifeWave products page, or read the overview on the LifeWave page.

It would be inaccurate to describe X39 as conventional photobiomodulation unless the terminology is scientifically and technically appropriate for its demonstrated mechanism. The relevant scientific question is not whether X39 is "stem-cell therapy." It plainly is not. The relevant question is whether wearing the technology can influence biological signaling or measurable biomarkers associated with regenerative physiology.

Does X39 increase GHK-Cu?

One published study reports a change in circulating GHK-Cu in adults who wore the X39 patch for one week. The trial was described as double-blind and randomized, with 60 participants aged 40 to 80, and it reported a statistically significant increase in GHK-Cu concentration in the active group compared with control. It is registered as a clinical trial on ClinicalTrials.gov.

Transparency requires stating clearly that this research is manufacturer-associated. The study was published in an open-access journal, and the same research group has authored other LifeWave-associated work. It should be treated as preliminary product-specific evidence, not as independent replication. Company-hosted or company-funded research is not equivalent to independent confirmation.

Larger studies, independent replication, longer follow-up and clinically meaningful endpoints would strengthen the evidence. Until then, the most accurate statement is that X39 has been associated with a reported change in GHK-Cu in a small, manufacturer-associated trial, and that the clinical significance of that change is not yet established. For a comprehensive review of all publicly accessible LifeWave research, see our LifeWave research library.

Does X39 activate stem cells?

What we know vs. what we're still investigating

Is X39 FDA approved?

It is important to use regulatory terms precisely. FDA approval, FDA clearance, FDA registration or listing, and the FDA framework for low-risk general-wellness products are different things.

"FDA approval" generally refers to the premarket approval process for high-risk devices, such as life-sustaining or implantable devices. "FDA clearance" typically refers to the 510(k) process for moderate-risk devices. "Registration and listing" means a facility and its products are registered with the FDA, which is not the same as the agency reviewing or validating a product's efficacy.

The FDA's "General Wellness: Policy for Low Risk Devices" guidance describes a framework for products that promote a healthy lifestyle and present a low risk to users. Products that fall within this policy are not required to obtain FDA premarket approval. This is a statement about the regulatory pathway, not about efficacy.

Lack of a requirement for FDA premarket approval does not mean the FDA has independently validated a product's efficacy or its marketing claims. Consumers should not interpret the absence of a premarket approval requirement as evidence of effectiveness.

Dr. Staci's perspective

Frequently asked questions

Scientific references