If you have been diagnosed with osteoporosis, you already know the goal: keep your bones strong enough that a stumble does not become a fracture. Red light therapy for osteoporosis works at the level where that outcome is actually decided: inside the cells that build and maintain bone. It delivers specific wavelengths of red and near-infrared light that reach bone tissue and switch on the biological processes that support bone formation, calm the inflammation that drives bone loss, and restore the cellular energy that bone repair depends on. The human research is early but consistent, and it now includes a randomized clinical trial that measured bone density directly in people with osteoporosis.
Key Takeaways
- A randomized clinical trial (Mohammadi et al., 2022) found that red light therapy produced significant increases in bone mineral density and in two blood markers of active bone building in people with osteoporosis. It is the first published randomized trial to test this therapy on bone density outcomes in osteoporosis patients.
- The finding repeats in other human research. A second study in spinal cord injury patients (Mohammadzadeh et al., 2024) found bone density gains at the hip and forearm that held at follow-up, and a controlled trial in elderly osteoporosis patients (Abdelaal et al., 2017) found significant bone density gains at treated sites while the untreated group showed no change.
- Red light therapy works through seven biological mechanisms that address the root causes of bone loss: restoring cellular energy, building new bone, slowing bone breakdown, reducing chronic inflammation, defending bone cells from oxidative stress, improving blood flow to bone, and supporting the estrogen-related pathways disrupted at menopause.
What Is Osteoporosis, and Why Do Current Treatments Leave Gaps?
Osteoporosis means “porous bone.” It is a disease of low bone mass and weakened bone structure that raises the risk of fracture. It develops quietly, and most people do not know they have it until a bone breaks. In the United States, an estimated 10.2 million adults over 50 have osteoporosis, with another 43.3 million living with low bone mass (Sarafrazi et al., 2021).
Bone is living tissue in constant renewal. One set of cells, called osteoclasts, breaks down old bone. Another set, called osteoblasts, builds new bone to replace it. In healthy bone these two processes stay balanced. In osteoporosis the balance tips toward breakdown, bone density drops, and fracture risk climbs. The disease affects women most, because the drop in estrogen after menopause speeds bone loss, though about one in five cases occurs in men.
Standard treatment relies on three main drug types. Bisphosphonates slow bone breakdown. Denosumab, an injection, blocks a signal that bone-destroying cells need to form. Teriparatide and similar drugs stimulate bone building. All three work, and all three carry limits: bisphosphonates carry rare but serious risks with long-term use, stopping denosumab can trigger rapid bone loss, and teriparatide is costly, requires daily injections, and is usually limited to two years. Each of these manages the disease from one direction. None of them restores the cellular energy that bone cells need to function. They do not quiet the chronic inflammation that accelerates breakdown, and the blood supply that feeds bone tissue, already diminished in aging bone, falls outside their reach entirely.
That gap in what current treatments address is what draws clinical attention to red light therapy.
Standard treatments for osteoporosis work, and they should stay in the picture. But they manage one piece of the problem at a time, and none of them restores the energy that bone cells need to do their job. That is where photobiomodulation gets interesting. The mechanism is solid: you are boosting cellular energy, lowering inflammation, and giving bone-forming cells a better environment to work in. The clinical data in osteoporosis is still thin, a few small trials, but every one of them has pointed the same direction. And the preclinical work is deep enough now that I would not call this speculative. I would call it early.— Dr. William Carter, MD
How Red Light Therapy Addresses Osteoporosis: Seven Biological Mechanisms
Red and near-infrared light in the 630 to 940 nanometer range passes through skin and into the tissue beneath, including bone. There it is absorbed by a light-sensitive molecule inside the cell’s energy factories, the mitochondria. That single absorption event sets off a chain of responses that matter for bone health. For a fuller explanation of the underlying biology, see our article on how red light therapy works at the cellular level.
1. Restoring Cellular Energy to Bone Cells
Every step of bone renewal runs on cellular energy, a molecule called ATP. Bone-building cells need it to produce the collagen framework and mineral deposits that make new bone. The cells embedded in bone that sense strain and direct repair need it to send their signals. In osteoporosis, these cells are chronically low on energy. Aging energy factories produce less ATP, and cell damage makes them less efficient. Bone cells cannot keep up with the demands of renewal when the energy is not there.
LED light at 670 and 830 nanometers can reactivate the cell’s main light-absorbing energy molecule and restore ATP production even in cells whose energy systems have been shut down. Wong-Riley et al. (2005) demonstrated this in The Journal of Biological Chemistry, confirming that the most effective wavelengths matched the natural absorption pattern of that molecule.
The effect has since been measured in living people. Fear et al. (2023) used a specialized MRI scan to track energy production in the brains of older adults before and after a single session of red light therapy and recorded a significant rise in the rate of ATP synthesis after just one treatment.
This energy effect follows a dosing rule worth knowing: low to moderate doses stimulate cells, while excessive doses can work against you. Huang et al. (2009) documented this pattern across many cell types, making it one of the most reliably repeated findings in the field. For bone health, this means more light is not always better, and the right dose matters.
For osteoporotic bone, this energy restoration is the foundation. A bone cell short on energy cannot build collagen, deposit minerals, or respond to the signals that tell it where new bone is needed. Restore its energy, and you restore its ability to take part in renewal.
2. Stimulating the Cells That Build Bone
Red light therapy stimulates bone-building cells to multiply, mature, and get to work. It has been measured in bone-forming cells themselves.
Three wavelengths were tested head-to-head on human bone-building cells and their precursors (Tani et al., 2018). Red light at 635 nanometers increased the markers of active bone formation in both cell types, and the treated cells went on to deposit hard, bone-like mineral nodules, the functional end product of bone building. A related study by Li et al. (2019) found that near-infrared light at 808 nanometers helped bone precursor cells multiply and protected them from programmed cell death.
Red light therapy also helps stem cells develop into bone-building cells. A review of the stem cell evidence (De Freitas and Hamblin, 2016) documented that the therapy boosts the growth and development of several stem cell types, including the precursors that become bone builders. This gives the body a larger supply of the cells that make new bone.
The human data confirms this is not confined to the lab. In the clinical trial by Mohammadi et al. (2022), patients showed a measured rise in osteocalcin, a protein made only by active bone-building cells during bone formation. Osteocalcin does not rise unless those cells are working. At the tissue level, Bossini et al. (2012) showed in osteoporotic rats that near-infrared laser produced significantly more newly formed bone and better-organized collagen at a bone repair site, with both treatment doses outperforming untreated controls.
3. Slowing the Cells That Break Down Bone
The other half of the osteoporosis problem is too much bone breakdown. The bone-dissolving cells become overactive, clearing bone faster than it can be rebuilt.
Red light therapy slows these cells through a specific structural effect. Lim et al. (2014) found that 635 nanometer LED light significantly reduced the formation of mature bone-dissolving cells. The light disrupted the internal scaffolding these cells need to seal onto a bone surface and dissolve it. Without that scaffolding, the cells cannot attach and cannot break bone down. Both the number of active cells and their actual bone-dissolving activity dropped significantly.
This is a direct anti-breakdown effect, the same general action as the leading osteoporosis drugs, reached through a completely different biological route.
4. Reducing the Chronic Inflammation That Drives Bone Loss
Low-grade, ongoing inflammation is now recognized as a central driver of osteoporosis. The same inflammatory signals that cause pain and damage in arthritis also push bone-dissolving cells into action while holding back bone builders. This inflammatory bone loss happens to everyone with age but speeds up sharply after menopause, with chronic inflammatory conditions, and with long-term steroid use.
Red light therapy lowers these specific inflammatory signals. A randomized, double-blind, placebo-controlled trial by Marashian et al. (2022) found that red LED light produced roughly an 82 percent drop in two key inflammatory signals in treated patients compared to their starting levels, while the placebo group showed no such drop. This was a small pilot-sized trial built to detect a signal; the effect was large, and larger studies will strengthen the finding.
Red light also shifts the body’s cleanup cells away from their inflammatory, tissue-damaging state and toward their repair state. Hamblin (2017) documented this shift, which matters for bone because the inflammatory state drives bone destruction while the repair state supports bone building. At the molecular level, Lim et al. (2013) showed that 635 nanometer light quieted the body’s master inflammatory switch in human gum tissue cells, the same switch that triggers the signal driving bone-dissolving cell formation.
For a deeper look at how red light therapy calms inflammation, see our complete article on red light therapy for inflammation.
5. Defending Bone Cells Against Oxidative Stress
Oxidative stress, the buildup of unstable molecules that damage cells, is an established driver of both bone-builder death and bone-dissolver activation in osteoporosis. Aging bone cells produce more of these damaging molecules and have weaker defenses against them. The environment that follows kills the cells that build bone while activating the ones that destroy it.
Red light therapy counters this in bone cells. Zuo et al. (2022) found that near-infrared light at 808 nanometers protected bone precursor cells from oxidative damage, rescued them from cell death, boosted bone-forming proteins, and switched on the cell’s internal repair system. The researchers concluded that their results lay the groundwork for using this therapy in osteoporosis treatment. Fu et al. (2023) added that red light at 625 nanometers protected bone cells from a form of stress that leads to cell death, connecting the energy-restoration effect to bone cell survival.
The broader pattern is well established. A systematic review by Dos Santos et al. (2017) found that red light therapy consistently reduced oxidative damage and raised the body’s antioxidant defenses across many animal models, making this one of the most reproducible findings in the field. In humans, a randomized trial in elite athletes (Tomazoni et al., 2019) showed that pre-exercise treatment significantly raised antioxidant defenses and lowered markers of oxidative damage. That study was set in exercise, but the same protective pathways apply to the oxidative stress that drives bone cell death in osteoporosis.
6. Improving Blood Flow and Building New Blood Vessels in Bone
Bone is living, blood-fed tissue. Oxygen, nutrients, and the signals that coordinate renewal all reach bone cells through blood vessels. In osteoporotic bone, that blood supply is often reduced, which starves bone cells of the raw materials they need.
Red light therapy improves blood flow in two ways. The fast effect works through nitric oxide, a molecule that widens blood vessels. When near-infrared light reaches the cell’s energy molecule, it releases nitric oxide that had been bound there, and blood vessels open. A randomized controlled trial by Gavish et al. (2020) measured a 27 percent rise in small-vessel blood flow from near-infrared light, building to 54 percent over twenty minutes.
Beyond that immediate effect, red light therapy stimulates the growth of new blood vessels. In the osteoporotic rat study by Bossini et al. (2012), the laser-treated groups showed a significant rise in the signal that drives new vessel growth directly into healing bone. New vessels mean better oxygen and nutrient delivery and faster clearance of waste from the repair site. For osteoporotic bone, that matters: bone formation needs a steady supply of calcium, phosphate, and the building blocks of collagen, and even active bone cells cannot build if those materials cannot reach them.
7. Supporting Estrogen-Related Bone Pathways
Loss of estrogen is the main driver of osteoporosis after menopause. Estrogen normally keeps renewal in balance by restraining bone-dissolving cells and supporting the ones that build. When estrogen falls, that balance collapses.
Most preclinical osteoporosis research on red light therapy uses the estrogen-depleted (ovariectomized) animal model, and the results in this model are strikingly consistent. The Shokri et al. (2023) study tested three wavelengths in these animals, and all three improved bone density. Bossini et al. (2012) showed improved bone repair in the same model, and Alibakhshi et al. (2024) found that laser therapy prevented bone loss in estrogen-depleted animals. Together these show that red light therapy produces bone benefits specifically in the estrogen-depleted state most relevant to postmenopausal osteoporosis.
Supporting this at the blood-vessel level, Silva et al. (2025) found that red light therapy in estrogen-depleted animals lowered blood pressure, raised nitric oxide, and reversed the blood-vessel dysfunction caused by estrogen loss. The heart and the skeleton share vascular biology, so the same improvements that restore blood vessel function also improve the blood supply to bone.
For more on how red light therapy supports the hormonal systems disrupted at menopause, see our article on red light therapy for women’s hormone health.
What the Human and Animal Evidence Shows
Human Clinical Trials
The anchor study is the Mohammadi et al. (2022) randomized clinical trial, published in Lasers in Surgery and Medicine. It is the first published randomized trial to test red light therapy on bone density and bone-formation markers in people diagnosed with osteoporosis. The trial found significant increases in all three of its main measures: bone mineral density rose at treated sites, and both blood markers of active bone building increased.
The Mohammadzadeh et al. (2024) study provides a second human dataset. Using a matched-pair design in eight patients with spinal cord injury and osteoporosis, researchers applied 830 nanometer laser three times weekly for eight weeks, using each patient’s untreated side as the comparison. Bone density rose significantly at the hip and forearm at both week 8 and week 15, meaning the gains were not only achieved during treatment but held after it ended. Vitamin D levels also rose significantly, a finding the authors flagged for further study. This study did not find changes in the two blood markers or in bone density at two other sites, a pattern consistent with effects that vary by skeletal location.
A controlled trial by Abdelaal et al. (2017), published in the Bulletin of Faculty of Physical Therapy, compared red light therapy against pulsed electromagnetic field therapy in elderly patients with osteoporosis. Both therapies produced significant bone density gains at treated sites, while the untreated group showed no significant change. This adds further human evidence that red light therapy can meaningfully improve bone density in osteoporosis patients.
Animal and Laboratory Evidence: The Consistency Is the Signal
The preclinical evidence is substantial and remarkably consistent across independent research groups.
The Shokri et al. (2023) study is the most complete wavelength comparison to date. Testing 660, 810, and 940 nanometer light in estrogen-depleted rats, it found that all three wavelengths significantly improved bone density compared to untreated controls, with no meaningful difference among them. The bone-building effect held across the full red-to-near-infrared range. The light therapy groups matched the results of a standard osteoporosis drug (zoledronic acid), and combining the light with the drug produced the best results of all.
Other groups reinforce this at the tissue and mechanical level. Bossini et al. (2012) showed near-infrared laser stimulated new bone formation, collagen deposit, and new blood vessel growth. Bayat et al. (2016) found that laser therapy improved the mechanical strength of osteoporotic spine bone. Fridoni et al. (2015) and Mohsenifar et al. (2016) added mechanical and gene-level evidence that the therapy improved bone quality, and Scalize et al. (2015) showed improved bone formation using detailed tissue analysis. This breadth is itself a meaningful signal: different countries, wavelengths, dosing protocols, and measurement approaches, all arriving at the same conclusion.
Newer reviews continue the trend. A 2025 meta-analysis of fracture healing in animal models (Hazrati et al., 2025) pooled 27 studies and found that red light therapy supported bone healing, adding weight to the case that the therapy improves the bone quality that underlies fracture resistance.
Strong evidence. The biological mechanisms by which red light therapy affects bone cells are documented across dozens of studies from independent groups: building bone, slowing breakdown, restoring energy, calming inflammation, defending against oxidative stress. The Mohammadi (2022) randomized trial provides the first direct human evidence for bone density improvement in osteoporosis patients, and the Mohammadzadeh (2024) and Abdelaal (2017) studies repeat the human bone density finding in different populations.
Promising and building. The combination of red light therapy with standard osteoporosis drugs has so far been tested only in animals (Shokri et al., 2023), where it produced added benefit. No human trial has yet tested the therapy alongside standard medications, which is a logical next step. The vitamin D rise seen in the Mohammadzadeh study is a single finding that needs repeating.
What has not been tested. No large-scale analysis focused specifically on red light therapy for whole-body osteoporosis exists yet, though a systematic review by Russo et al. (2023) surveyed the evidence and found consistent positive signals. No head-to-head human trial has compared the therapy against a standard osteoporosis drug. The human evidence rests on three studies with relatively small sample sizes; the direction is consistently positive, but the volume is not yet enough for firm clinical guidelines. A 2025 review of bone-regeneration trials (Sadeghian et al., 2025) found the same unevenness: across 13 clinical studies, several showed clear bone benefit while others showed no significant effect, underscoring that treatment settings and dosing still need to be worked out.
Conclusion
Osteoporosis is a disease of cellular failure. The cells that build bone run short on energy, and the inflammatory signals that accelerate breakdown do not quiet. Meanwhile, the cells that dissolve bone outpace the ones trying to rebuild it, in a body where the blood supply has weakened and the defenses protecting bone cells have worn thin.
Red and near-infrared light therapy addresses these failures through documented biological mechanisms. It restores the energy that bone cells need and stimulates the ones responsible for building new bone. It slows the cells that break bone down, calms the chronic inflammation behind much of that breakdown, and protects bone cells from the oxidative damage that accumulates with age. It improves blood flow to bone tissue. And in estrogen-depleted models, the ones most relevant to postmenopausal osteoporosis, these effects hold.
The clinical evidence is early but positive. Multiple human studies have found significant improvements in bone density or bone-formation markers, and more than a dozen animal studies from independent groups consistently show the same. The mechanisms are well established and specific to how osteoporosis actually damages bone. For people managing osteoporosis or facing bone loss, this therapy supports the cellular processes that calcium, vitamin D, exercise, and medication all depend on. It is evidence worth bringing to your healthcare provider, so you can decide what belongs in your own plan.
