Last reviewed: May 12, 2026 Last updated: May 12, 2026

Written by: Jay Hastings , CEO of PlexusDx

Jay Hastings is the CEO of PlexusDx, a precision health company focused on genetic testing, blood biomarker insights, and personalized wellness recommendations. He has more than 20 years of experience across healthcare innovation, genomics, laboratory operations, healthcare investing, and strategic finance. His work has included scaling healthcare startups, leading CLIA lab integrations, and helping expand consumer access to precision health tools.

Medically reviewed by: Jayden Lee, PharmD, EMBA

Jayden Lee, PharmD, EMBA, is the PlexusDx Medical Science Liaison with a PharmD and MBA specializing in pharmacogenomics and clinical product development, with a proven ability to bridge the gap between genomic research and practical patient outcomes. Dr. Lee has more than 10 years of professional experience in clinical pharmacy, academia, and research.

Understanding GSTP1 and Phase 2 Detoxification

Phase 2 detoxification is a crucial part of how your body neutralizes and removes potentially harmful compounds. During this phase, enzymes like glutathione S-transferases attach water-soluble groups such as glutathione to toxic molecules, making them easier to excrete. The GSTP1 gene encodes one of these enzymes, glutathione S-transferase P1, which is especially active in the liver and lungs. Variations in GSTP1 can change how well this enzyme works and influence individual sensitivity to environmental toxins.

What the rs1695 (Ile105Val) Variant Means

The rs1695 variant, also known as Ile105Val, changes the GSTP1 enzyme structure and can affect how effectively it binds toxins to glutathione. The G allele (Val) is associated with reduced enzyme activity compared with the A allele (Ile). Depending on whether you carry 0, 1, or 2 copies of the effect allele, your Phase 2 detox capacity may be higher or lower. Below are practical explanations of each genotype and evidence-based steps you can take to support detoxification pathways.

Practical Diet, Supplement, Lifestyle and Testing Recommendations

Regardless of genotype, supporting your body's detox systems is beneficial. The suggestions below are educational and intended to help you discuss appropriate steps with your healthcare provider.

Dietary Recommendations

  • Eat a variety of colorful fruits and vegetables daily to provide antioxidants that reduce oxidative stress and support detox enzymes.
  • Prioritize cruciferous vegetables (broccoli, Brussels sprouts, kale, cauliflower) to boost Phase 2 enzyme activity and support glutathione-related pathways.
  • Include allium vegetables (garlic, onions, leeks) which contain sulfur compounds that aid glutathione production.
  • Consume adequate high-quality protein (fish, poultry, legumes) to supply amino acids cysteine, glycine and glutamate for glutathione synthesis.
  • Include healthy fats (olive oil, avocados, nuts, fatty fish) to support cell membranes and reduce inflammation.
  • Limit processed foods, excessive fried or charred foods, and reduce processed sugars which can increase oxidative stress.

Supplements to Consider

Discuss these options with your healthcare provider. Supplements may help when diet alone is insufficient.

  • L-Glutathione or N-acetylcysteine (NAC) to support glutathione levels and Phase 2 conjugation.
  • Alpha-lipoic acid for antioxidant support and regeneration of glutathione.
  • Vitamin C and vitamin E as complementary antioxidants.
  • Sulfur-containing supplements such as milk thistle or SAMe may support liver detox pathways.
  • Multivitamin with adequate B vitamins, particularly B6, B12 and folate, which support methylation and detox cofactor needs.

Lifestyle Recommendations

  • Minimize exposure to toxins: avoid smoking and secondhand smoke, limit consumption of high-mercury fish, reduce use of plastic food containers and canned foods that may leach BPA, and choose lower-pesticide produce when possible.
  • Improve indoor air: use ventilation, HEPA filtration, and avoid idling vehicles or heavy chemical use near living spaces.
  • Maintain regular physical activity to support circulation, lymphatic flow and sweat-mediated elimination of some toxins.
  • Stay well hydrated to promote renal clearance of water-soluble conjugates.
  • Practice safe food preparation: avoid charring meats and reduce consumption of heavily grilled or smoked foods.
  • Manage stress and get sufficient sleep, as recovery supports efficient detox and cellular repair.

Blood Tests and Monitoring

  • Basic metabolic panel and liver function tests (ALT, AST, GGT) to screen organ systems involved in detox.
  • Urinary or blood heavy metal testing if exposure is suspected.
  • Nutrient panels to check levels of vitamins, selenium, and markers related to oxidative stress and glutathione status if clinically indicated.
  • Discuss targeted testing with your healthcare provider based on exposure history and symptoms.

Genetic Interpretation: GSTP1 rs1695

Two effect alleles (GG) — Reduced GSTP1 activity

Individuals with the GG genotype have two copies of the G (Val) allele for rs1695. This genotype is associated with reduced GSTP1 enzyme activity. As a result, Phase 2 conjugation with glutathione may be less efficient, which can lead to decreased capacity to neutralize and eliminate common environmental toxins. Substances that may be more challenging to process include:

  • Polycyclic aromatic hydrocarbons from air pollution and charred foods
  • Organophosphate pesticide residues
  • Mercury from certain fish and dental amalgams
  • Benzene from vehicle exhaust and industrial sources
  • BPA and other plastic-derived chemicals
  • Heavy metals such as cadmium and arsenic

Actionable steps:

  • Emphasize cruciferous and allium vegetables, adequate protein, and sulfur-rich foods to support glutathione production.
  • Consider discussing supplements such as NAC, glutathione, and alpha-lipoic acid with your provider.
  • Reduce known exposures at home and work, improve indoor air quality, and choose lower-toxin personal care and household products.
  • Monitor liver function and heavy metals if exposure risk is present.
One effect allele (AG) — Moderately reduced GSTP1 activity

With the AG genotype, you carry one copy of the G (Val) allele and one copy of the A (Ile) allele. This tends to result in a modest reduction of GSTP1 activity compared with the AA genotype but generally better activity than GG. You may have slightly lower efficiency in conjugating glutathione to toxins, which could translate to increased sensitivity to environmental pollutants including cigarette smoke, pesticides, mercury, and BPA.

Actionable steps:

  • Follow a detox-supportive diet rich in cruciferous and allium vegetables and ensure adequate high-quality protein intake.
  • Hydrate well and maintain regular exercise and sleep habits.
  • Consider antioxidant support and discuss targeted supplements with your healthcare provider if needed.
  • Minimize exposures by choosing safer household products and reducing consumption of high-mercury fish and heavily processed foods.
Zero effect alleles (AA) — Typical or enhanced GSTP1 activity

The AA genotype indicates two copies of the A (Ile) allele and is associated with favorable GSTP1 enzyme function. This genotype generally supports effective Phase 2 conjugation with glutathione, enabling more efficient neutralization and elimination of many environmental toxins. While this is a protective factor, maintaining healthy lifestyle and exposure-reduction practices remains important.

Actionable steps:

  • Continue a balanced diet rich in antioxidants, cruciferous and allium vegetables, and adequate protein to preserve optimal detox capacity.
  • Maintain healthy lifestyle habits—exercise, hydration, sleep, and stress management—to support ongoing detoxification.
  • Practice exposure minimization strategies even when genetic capacity is favorable.

Important Disclaimer

PlexusDx provides educational information about genetic predispositions only. This content is not medical advice and should not replace consultation with a qualified healthcare professional. Discuss genetic results, testing, or any changes to diet, supplements, or medications with your healthcare provider to determine what is safe and appropriate for your individual health circumstances.

If this genetic variant is present in your PlexusDx results, the following tests and reports are commonly used to explore it further:

🧬 Genetic Tests:

🧪 Blood Tests:

📄 Genetic Report:

Frequently Asked Questions About PHASE 2 DETOX and GSTP1 rs1695

How does the GSTP1 rs1695 (Ile105Val) variant affect Phase 2 detoxification?

GSTP1 helps drive Phase 2 detoxification by conjugating water-soluble groups like glutathione to toxins so they can be excreted. The rs1695 (Ile105Val) variant can change how effectively the GSTP1 enzyme binds toxins to glutathione, which may influence individual sensitivity to environmental toxins depending on whether you carry 0, 1, or 2 copies of the effect allele (G/Val).

What do GSTP1 rs1695 genotypes (AA, AG, GG) mean for my detox capacity and toxin sensitivity?

AA (zero effect alleles) is generally linked to typical or more favorable GSTP1 activity, supporting more efficient glutathione conjugation. AG (one effect allele) is associated with a modest reduction in GSTP1 activity, which may mean slightly increased sensitivity to pollutants such as cigarette smoke, pesticides, mercury, and BPA. GG (two effect alleles) is associated with reduced GSTP1 activity, which may make Phase 2 conjugation less efficient and potentially increase difficulty processing toxins such as charred food compounds (polycyclic aromatic hydrocarbons), organophosphate residues, mercury, benzene, BPA/plastic-derived chemicals, and heavy metals.

What diet, supplement, and testing steps can support detoxification with the GSTP1 rs1695 variant?

Regardless of genotype, you can support detox pathways by eating a variety of colorful fruits and vegetables, emphasizing cruciferous vegetables and allium vegetables, and ensuring adequate high-quality protein to supply amino acids for glutathione synthesis; healthy fats can also support anti-inflammatory health. If diet alone isn’t enough, some people discuss supplements like L-glutathione or NAC, alpha-lipoic acid, vitamins C and E, and sulfur-containing options (such as milk thistle or SAMe), as well as a multivitamin with sufficient B vitamins (including B6, B12, and folate) with their healthcare provider. For monitoring, commonly discussed options include liver function tests (ALT, AST, GGT) and, when exposure is suspected, urinary or blood heavy metal testing and nutrient panels related to oxidative stress and glutathione status.

What tests can help me learn more about PHASE 2 DETOX and GSTP1 rs1695?

The Functional Health Genetic Test delivers over 750 personalized genetic insights across 10 in-depth genetic reports to support whole-body, systems-level health understanding. The Detoxification Genetic Report translates your results into personalized, actionable guidance. Your healthcare provider can also recommend targeted blood tests based on your specific pathway results and health history to complement your genetic insights with current biomarker data.

Medical and Editorial Standards

Medical review process: This article was reviewed for medical accuracy, scientific clarity, evidence alignment, and appropriate discussion of genetics, medications, supplements, biomarkers, and health-related claims.

Sources and evidence: PlexusDx educational content is developed using peer-reviewed research, clinical literature, reputable medical references, and, where applicable, public health or regulatory guidance. References are included at the end of the article when scientific, medical, or health-related claims are discussed.

Commercial transparency: PlexusDx offers genetic testing, blood biomarker testing, personalized supplement recommendations, and related precision wellness services. Product mentions are intended to help readers understand available options and should not be interpreted as medical advice.

Important disclaimer: PlexusDx educational content is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about medications, supplements, genetic testing, lab testing, or health-related care.