Can red light therapy (Low-Level Laser Therapy (LLLT) or Photobiomodulation (PBM)) improve egg quality in women of reproductive age undergoing In Vitro Fertilization (IVF), particularly those with Polycystic Ovary Syndrome (PCOS) or endometriosis?

Red Light Therapy and Egg Quality in IVF

Red light therapy (photobiomodulation/LLLT) is not currently recommended as a standard treatment to improve egg quality in women undergoing IVF, as it is not included in any major fertility preservation or IVF guidelines from ASRM, ESHRE, or ASCO, and lacks robust clinical trial evidence demonstrating improved live birth rates.

Current Guideline-Based Approaches for Women with PCOS or Endometriosis

For PCOS Patients Undergoing IVF

Established first-line interventions focus on lifestyle modification and metabolic optimization:

• Weight loss of 5-10% of initial body weight through diet (1,200-1,500 kcal/day with 500-750 kcal/day deficit) and exercise (≥250 minutes/week moderate-intensity activity) significantly improves ovulation and pregnancy rates 1
• Clomiphene citrate remains the first-line medical treatment for ovulation induction in PCOS patients without other infertility factors, achieving 80% ovulation rates and 50% conception rates 2
• Metabolic screening including fasting glucose, 2-hour glucose tolerance test, and lipid profile must be completed before initiating fertility treatment 1
• For patients requiring IVF, immature oocyte harvesting followed by in vitro maturation (IVM) is an established option for PCOS patients unable to undergo standard controlled ovarian stimulation 2

For Endometriosis Patients Undergoing IVF

Current evidence-based approaches target the underlying pathophysiology:

• Anti-inflammatory agents and antioxidant supplementation may improve oocyte quality, implantation rates, and clinical pregnancy rates in endometriosis patients 3
• Women with endometriosis face increased risk of premature ovarian insufficiency (POI), with approximately 50% experiencing infertility 2
• Fertility preservation through oocyte or embryo cryopreservation should be considered for women with bilateral unoperated endometriomas or those requiring repeat surgery for contralateral recurrence 2

Emerging Research on Red Light Therapy: Preliminary but Insufficient Evidence

Limited Clinical Data

The only available clinical evidence consists of a small case series without controlled comparison:

• A 2024 case series of three women with unexplained infertility reported successful pregnancies following multiwavelength red/near-infrared PBM (600-1000 nm) administered weekly or biweekly 4
• This study included women with multiple miscarriages, non-viable IVF embryos, and failed PGT-A embryo implantation 4
• Critical limitation: This is a case series without controls, randomization, or blinding—the lowest level of clinical evidence

In Vitro Laboratory Studies

Laboratory research suggests potential mechanisms but lacks clinical validation:

• A 2018 in vitro study demonstrated that 635 nm LLLT at 4.27 J/cm² increased proliferation and functional gene expression (MUC1, ITGA5, ITGB3, LIF, PTEN) in cultured endometrial cells 5
• Multiple exposures showed greater effects on cell surface area and PTEN tumor suppressor gene expression compared to single exposure 5
• However, in vitro cellular responses do not necessarily translate to improved clinical outcomes such as live birth rates

Why Red Light Therapy Cannot Be Recommended

Absence from Clinical Guidelines

No major reproductive medicine society includes PBM/LLLT in their treatment algorithms:

• The 2025 ASCO fertility preservation guidelines comprehensively review all evidence-based fertility preservation procedures but make no mention of red light therapy 2
• The 2017 ESHRE-ASRM expert meeting on fertility preservation identifies oocyte/embryo cryopreservation and IVM as first-line methods, with no discussion of photobiomodulation 2
• The 2024 ESHRE guidelines on embryo transfer and the 2003 ACOG guidelines on PCOS management do not reference light therapy 2

Lack of Outcome Data on Morbidity, Mortality, and Quality of Life

The existing evidence does not demonstrate improvements in the outcomes that matter most:

• No randomized controlled trials have evaluated red light therapy's effect on live birth rates, miscarriage rates, or maternal/neonatal complications
• The case series 4 lacks comparison groups to determine whether outcomes differ from natural conception rates or standard IVF protocols
• No data exist on potential harms, optimal dosing protocols, treatment duration, or which patient populations might benefit

Established Alternatives with Proven Efficacy

For both PCOS and endometriosis patients, evidence-based interventions already exist:

• Lifestyle modification, metabolic optimization, and clomiphene citrate for PCOS have decades of supporting evidence 2, 1, 6
• Antioxidant supplementation and anti-inflammatory agents for endometriosis patients show promise in improving IVF outcomes 3
• Advanced techniques like IVM for PCOS patients and PGT-A for embryo selection in older women have established roles 2, 7

Clinical Approach: What to Recommend Instead

For PCOS Patients

1. Initiate lifestyle modification immediately: 5-10% weight loss target, 1,200-1,500 kcal/day diet, ≥250 min/week exercise 1
2. Complete metabolic screening: Fasting glucose, 2-hour GTT, lipid profile; ensure BMI ≥18.5 kg/m² before ovulation induction 1
3. First-line ovulation induction: Clomiphene citrate (up to 150 mg/day for maximum 6 cycles) 2, 1
4. If clomiphene fails: Low-dose gonadotropin therapy or consider IVM if standard COS is contraindicated 2

For Endometriosis Patients

1. Consider fertility preservation: Oocyte/embryo cryopreservation before surgical treatment, especially for bilateral disease 2
2. Optimize follicular environment: Antioxidant supplementation and anti-inflammatory agents to address oxidative stress and inflammation 3
3. Address multiple mechanisms: Target dysregulated steroidogenesis, cell cycle progression, and impaired angiogenesis 3
4. Standard IVF protocols: Single embryo transfer with PGT-A when appropriate 2

Important Caveats

Avoid premature adoption of unproven therapies:

• The enthusiasm for novel interventions must be tempered by the lack of rigorous clinical trial data demonstrating safety and efficacy
• Women with PCOS and endometriosis already face significant emotional and financial burdens; unproven treatments may delay effective interventions
• If patients inquire about red light therapy, acknowledge the preliminary laboratory data but emphasize the absence of clinical trial evidence and guideline support

Monitor for emerging evidence:

• Future randomized controlled trials with adequate sample sizes, proper controls, and live birth as the primary outcome would be necessary to change this recommendation
• Any such trials should also evaluate cost-effectiveness, optimal treatment protocols, and patient selection criteria