From the Research
Red light therapy stimulates hair growth at the follicular level by increasing cellular energy production, improving blood circulation, and promoting the transition of hair follicles from the telogen to anagen phase, as demonstrated by a study published in 2021 1.
Mechanism of Action
The exact mechanism of red light therapy on hair growth is complex and involves multiple biological processes. However, it is believed that red light wavelengths, typically between 630-670nm, penetrate the scalp and are absorbed by mitochondria in hair follicle cells, stimulating the production of adenosine triphosphate (ATP) 1. This increase in cellular energy helps to promote hair growth by:
- Enhancing blood flow to the scalp, delivering more oxygen and nutrients to hair follicles while removing waste products
- Reducing inflammation around hair follicles
- Decreasing oxidative stress that can damage follicles
- Upregulating the production of proteins and growth factors necessary for hair growth
Key Findings
A study published in 2021 found that low-level 650 nm red light promoted the proliferation of human hair follicles in an experimental cultured-tissue model, and significantly delayed the transition of hair cycle from anagen to catagen in vitro 1. Another study published in 2013 demonstrated that low-level laser therapy (LLLT) at 655 nm significantly improved hair counts in males with androgenetic alopecia 2. Similar results were observed in females with androgenetic alopecia, with a 37% increase in hair growth in the active treatment group compared to the placebo group 3.
Treatment Recommendations
For optimal results, treatments typically involve 10-20 minute sessions, 3-4 times weekly, using devices with appropriate wavelengths and power density (3-6 J/cm²) 1, 2, 3. Consistency is key, with visible improvements often requiring 3-6 months of regular use. It is also recommended to combine red light therapy with other treatments, such as minoxidil 5% solution, to enhance its effectiveness 4, 5.