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.

How PDE8B and rs6885099 Affect Thyroid Health

The thyroid gland produces hormones that regulate metabolism, energy, and overall hormone balance. These hormones play a crucial role in men's hormone and fertility health. The PDE8B gene influences levels of thyroid-stimulating hormone, or TSH, which signals the thyroid to make hormones. Variations at rs6885099 in PDE8B can slightly change baseline TSH. Those changes may alter risk for thyroid-related issues, but lifestyle, diet, environment, and medical care are important modifiers.

What TSH Changes Mean

  • Lower TSH generally suggests the body maintains thyroid hormones at a lower-stimulated baseline and is often associated with a reduced risk of hypothyroidism.
  • Average TSH indicates typical baseline regulation and standard risk for thyroid conditions.
  • TSH results must be interpreted with thyroid hormone levels and symptoms. Genetic tendencies are one piece of the picture.

Genetic Interpretation

2 effect alleles (AA) — decreased TSH

You carry two copies of the A allele at rs6885099 in PDE8B. This genotype is associated with decreased TSH levels, which generally indicates a lower risk for developing hypothyroidism. Your thyroid likely maintains a lower baseline TSH while producing adequate thyroid hormones. Despite this genetic tendency, lower TSH can sometimes mask underlying issues, so watch for symptoms and consider routine monitoring.

1 effect allele (AG) — mildly decreased TSH

You carry one copy of the A allele at rs6885099. This genotype is associated with slightly decreased TSH compared to typical levels, suggesting a mildly reduced risk for hypothyroidism. Effects are subtle and lifestyle, environment, and other genes can change actual thyroid function. Pay attention to symptoms and check labs if concerns arise.

0 effect alleles (GG) — typical TSH

You carry two copies of the G allele at rs6885099, associated with average TSH levels and typical thyroid regulation. Your genetic baseline does not suggest a protective or elevated risk related to this variant. Standard preventive measures and symptom-based monitoring are appropriate.

Diet and Nutrients to Support Thyroid Function

A balanced diet helps the thyroid do its job. Focus on whole foods and adequate intake of key nutrients rather than high-dose supplements unless recommended by a healthcare provider.

  • Iodine — Needed for thyroid hormone production. Sources: iodized salt, seafood, dairy, and eggs. Avoid excessive iodine from supplements unless guided by a clinician.
  • Selenium — Supports conversion and antioxidant protection of the thyroid. Sources: Brazil nuts (1–2 nuts per day), seafood, eggs.
  • Zinc — Helps hormone conversion and cellular signaling. Sources: shellfish, red meat, poultry, pumpkin seeds.
  • Vitamin D — Important for immune and endocrine health. Sources: sunlight, fatty fish, fortified foods. Check levels before supplementing.
  • Vitamin A — Supports thyroid hormone action and immune balance. Sources: liver in moderation, eggs, colorful vegetables with beta-carotene.
  • Cruciferous vegetables and soy — Moderate intake is generally safe for most people. Cooking reduces any mild goitrogenic effects. Those with iodine deficiency should be mindful of very high raw intakes.

Supplement and Food Guidance

  • Avoid routine high-dose iodine supplements unless a provider confirms deficiency.
  • Limit single-source reliance on supplements; aim to get nutrients largely from food.
  • Small amounts of Brazil nuts provide selenium; do not exceed recommended serving regularly to avoid excess selenium.
  • Consider vitamin D supplementation if blood tests show insufficiency. Work with your healthcare provider to pick the right dose.

Lifestyle, Environment, and Stress

  • Minimize exposure to endocrine-disrupting chemicals found in some plastics, personal care products, and household items. Choose glass or stainless steel for food storage when possible and avoid heating plastic containers.
  • Reduce chronic stress through sleep, regular exercise, and stress-management practices. High stress can affect thyroid regulation and overall hormonal balance.
  • Maintain a balanced, anti-inflammatory diet rich in vegetables, fruits, healthy fats, lean proteins, and whole grains.
  • Aim for consistent sleep patterns and regular moderate exercise to support metabolism and hormonal health.

When to Test and What to Monitor

Genetic tendencies are informative but not diagnostic. Monitoring with blood tests and symptom tracking is important.

  • Primary labs: TSH, free T4, and free T3. For some people, thyroid antibodies (TPO and Tg antibodies) are useful to screen for autoimmune thyroid disease.
  • Check vitamin D and, if indicated, selenium or iodine status with a provider before supplementing.
  • If you have symptoms like unexplained fatigue, weight changes, cold sensitivity, low libido, or changes in mood, discuss testing with your healthcare provider.
  • Regular routine screening intervals depend on age, symptoms, and medical history. Discuss a plan with your clinician.

Putting This Result Into Context

Your PDE8B rs6885099 genotype may nudge baseline TSH up or down slightly. This can influence predicted risk for hypothyroidism, but it does not determine your thyroid health alone. Diet, nutrient status, environmental exposures, stress, other genes, medications, and medical conditions all interact to shape thyroid function.

Practical Next Steps

  • Review your diet to ensure adequate iodine, selenium, zinc, vitamin D, and vitamin A from food sources.
  • Limit exposure to plastics and avoid unnecessary endocrine-disrupting chemicals.
  • Manage stress with sleep, exercise, and relaxation techniques.
  • Discuss thyroid symptom monitoring and appropriate lab testing with your healthcare provider, especially if you notice changes in energy, weight, mood, or sexual function.

Important Disclaimer

PlexusDx provides educational information about genetic predispositions only. This content is not medical advice. Always consult your healthcare provider before making changes to diet, supplements, or medical care, and before interpreting genetic or laboratory results in the context of your personal health.

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 Thyroid and PDE8B rs6885099

How does PDE8B rs6885099 influence thyroid health?

PDE8B affects thyroid-stimulating hormone (TSH), which signals the thyroid to produce hormones. Variations at rs6885099 can slightly shift your baseline TSH, which may subtly influence thyroid-related risk. However, actual thyroid function depends on many factors, including nutrients, stress, environment, medical history, and other genes.

What do different rs6885099 genotypes mean for TSH and hypothyroidism risk?

Two effect alleles (AA) are associated with decreased TSH and generally a reduced risk of hypothyroidism, but lower TSH can sometimes mask underlying issues—so symptoms and monitoring matter. One effect allele (AG) is linked to mildly decreased TSH and a slightly reduced hypothyroidism risk. Zero effect alleles (GG) is associated with typical TSH and typical thyroid regulation related to this variant.

What should I do to support thyroid function if I carry rs6885099 in PDE8B?

Focus on a balanced diet with adequate iodine, selenium, zinc, and vitamins D and A (avoid routine high-dose iodine supplements unless guided by a clinician). Support thyroid regulation with consistent sleep, regular moderate exercise, and stress-management. Minimize exposure to endocrine-disrupting chemicals (e.g., by avoiding heating food in plastic). If you have symptoms like unexplained fatigue, weight changes, cold sensitivity, low libido, or mood changes, discuss appropriate lab testing with your healthcare provider (commonly TSH, free T4, and free T3, and sometimes thyroid antibodies).

What tests can help me learn more about Thyroid and PDE8B rs6885099?

The Hormone, Thyroid, and Reproductive Health Genetic Test delivers over 85 personalized genetic insights through a comprehensive Hormone & Fertility Genetic Report, explaining inherited tendencies related to hormonal balance, reproductive function, and endocrine signaling. The Mens Hormone and Fertility Health 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.