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.

FOXE1 and Thyroid Health: What Your rs965513 Genotype Means for Men’s Hormone and Fertility Health

The thyroid gland plays a central role in regulating metabolism, energy, and reproductive hormones. The FOXE1 gene helps guide thyroid development and function. A common genetic variant near FOXE1, called rs965513, is associated with differences in thyroid-stimulating hormone or TSH and with varying risk of thyroid-related conditions. Below is an easy to read guide to what each genotype means and practical steps to support thyroid health.

Why the thyroid matters for men

  • Thyroid hormones influence metabolic rate, energy, mood, libido, and sperm production.
  • Even subtle thyroid changes can affect testosterone balance and fertility.
  • Early recognition and management of thyroid issues supports overall well being and reproductive health.

How FOXE1 and rs965513 affect thyroid function

The rs965513 variant near FOXE1 can influence TSH levels. Certain versions of this variant are linked to lower TSH and a higher risk of thyroid conditions, including papillary thyroid carcinoma and goiter. Knowing your genotype can help you and your clinician decide how aggressively to monitor thyroid health and which lifestyle or nutritional steps may be most useful.

AA genotype — two effect alleles

If you have the AA genotype you carry two copies of the effect allele. This is associated with decreased TSH levels and a higher risk of thyroid cancer, especially papillary thyroid carcinoma. You may also have an increased susceptibility to goiter.

What to watch for

  • Neck swelling or lumps
  • Persistent hoarseness or voice changes
  • Unexplained weight gain or loss
  • New fatigue, changes in libido, or fertility concerns

Recommended monitoring and actions

  • Discuss baseline and periodic blood tests with your provider: TSH, free T4, free T3.
  • Consider thyroid ultrasound if you have symptoms, nodules, or family history.
  • Maintain a balanced iodine intake. Avoid both deficiency and excess.
  • Ensure adequate selenium and zinc from diet or supplements if deficient.
  • Optimize vitamin D and vitamin A through safe sun exposure and diet.
  • Reduce exposure to endocrine disruptors such as certain plastics and household chemicals.
  • Follow an anti-inflammatory diet and avoid smoking.
AG genotype — one effect allele

If you have the AG genotype you carry one copy of the effect allele. This is associated with a modest decrease in TSH compared to people with no A allele. Your risk of thyroid cancer and goiter is higher than someone without any A alleles but lower than someone with two.

What to watch for

  • New or persistent neck lumps or fullness
  • Changes in voice, energy, weight, or libido
  • Family history of thyroid disease or thyroid cancer

Recommended monitoring and actions

  • Periodic screening with TSH, free T4, and free T3 as advised by your healthcare provider.
  • Discuss ultrasound imaging if you develop symptoms or if family history is present.
  • Support thyroid health with balanced iodine, adequate selenium and zinc, and sufficient vitamins D and A.
  • Limit exposure to endocrine disrupting chemicals, cook goitrogenic vegetables, and follow an anti-inflammatory diet.
  • Avoid smoking and maintain regular clinical follow up if symptoms arise.
GG genotype — zero effect alleles

If you have the GG genotype you carry two copies of the common non-effect allele. This is associated with typical TSH levels and normal baseline risk for thyroid conditions. Your FOXE1 variant does not raise your genetic predisposition to thyroid cancer.

What to watch for

  • Routine signs of thyroid dysfunction such as fatigue, weight change, mood shifts, or changes in libido or fertility
  • Any neck lumps, pain, or voice changes

Recommended monitoring and actions

  • Maintain routine clinical screening as recommended by your provider. Periodic TSH checks are standard for many adults.
  • Support thyroid health through diet, nutrient adequacy, and lifestyle measures described below.
  • Seek evaluation if symptoms or family history suggest a higher thyroid risk.

Diet and nutrient guidance to support thyroid health

  • Iodine: Aim for adequate but not excessive iodine. Good sources include iodized salt, seaweed (use cautiously), seafood, and dairy. Excessive iodine can worsen some thyroid conditions, so stick to recommended amounts and discuss supplements with your clinician.
  • Selenium: Important for conversion of T4 to T3 and for antioxidant protection in the thyroid. Sources include Brazil nuts (eat sparingly), seafood, eggs, and legumes. Typical supplementation should be guided by testing and provider advice.
  • Zinc: Supports thyroid hormone production and immune function. Found in oysters, shellfish, meat, seeds, and nuts.
  • Vitamin D: Maintain adequate vitamin D for immune regulation and overall endocrine health. Sun exposure and vitamin D rich foods or supplements as needed after testing.
  • Vitamin A: Necessary for thyroid hormone receptor function. Obtain from colorful vegetables, liver in moderation, and dairy products.
  • Goitrogens: Vegetables like broccoli, cauliflower, kale, and soy contain compounds that can interfere with thyroid function when consumed raw in very large amounts. Cooking reduces these compounds. For most people, normal consumption is safe.
  • Anti-inflammatory eating: Emphasize whole foods, healthy fats, lean proteins, vegetables, and lower processed carbohydrate intake to reduce inflammation and support hormone balance.

Supplements and tests to consider

  • Baseline blood tests: TSH, free T4, free T3, and if indicated, thyroid peroxidase and thyroglobulin antibodies. Discuss ultrasound if nodules or family history exist.
  • Selenium and zinc supplements: Consider only if dietary intake is inadequate or testing shows deficiency; take under healthcare supervision.
  • Vitamin D: Test 25(OH)D level before supplementing and follow provider recommendations.
  • Iodine supplements: Use caution. Do not supplement with iodine unless directed by a clinician.

Lifestyle steps to reduce risk and support thyroid function

  • Limit exposure to endocrine disruptors: Replace plastics with glass or stainless steel for food storage, avoid microwaving food in plastic, choose fragrance free personal care products when possible, and reduce exposure to pesticides.
  • Quit smoking: Smoking is linked with adverse thyroid outcomes and impacts overall hormone health.
  • Manage inflammation and stress: Regular sleep, physical activity, and stress reduction practices support thyroid and reproductive hormones.
  • Regular medical follow up: If you have symptoms, family history, or the AA or AG genotypes, maintain closer monitoring as suggested by your clinician.

When to contact your healthcare provider

  • New or growing neck lumps or persistent neck fullness
  • Persistent hoarseness or changes in voice
  • Unexplained weight changes, fatigue, changes in libido, or fertility concerns
  • Abnormal thyroid blood tests

PlexusDx provides education about genetic predispositions and does not provide medical advice. This information is intended to help you discuss genetics and thyroid health with your healthcare provider. Always consult your provider before making medical decisions, starting supplements, or changing treatments or testing plans.

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 FOXE1 rs965513

What does the FOXE1 rs965513 variant mean for men’s thyroid and TSH levels?

The FOXE1 rs965513 variant is associated with differences in thyroid-stimulating hormone (TSH). Some rs965513 genotypes are linked to lower TSH and a higher risk of thyroid conditions, which matters for men because thyroid hormones influence energy, mood, libido, metabolic rate, testosterone balance, and sperm production.

How do the AA, AG, and GG genotypes of rs965513 differ in thyroid risk?

AA (two effect alleles) is linked to decreased TSH and a higher risk of thyroid cancer (especially papillary thyroid carcinoma) and increased susceptibility to goiter. AG (one effect allele) is linked to a modest decrease in TSH with higher risk than GG, but lower than AA. GG (zero effect alleles) is associated with typical TSH levels and baseline genetic predisposition to thyroid conditions.

What monitoring and lifestyle steps are recommended for rs965513-associated thyroid health?

Discuss baseline and periodic thyroid blood tests (TSH, free T4, free T3) with your clinician, and consider thyroid ultrasound if you have symptoms, nodules, or family history. Support thyroid function with balanced iodine intake (avoid deficiency and excess), adequate selenium and zinc, and sufficient vitamin D and vitamin A. Reduce endocrine disruptor exposure (e.g., plastics/household chemicals), avoid smoking, and follow an anti-inflammatory diet while managing stress. Contact your healthcare provider for symptoms like new neck lumps, persistent hoarseness, unexplained weight change, fatigue, libido changes, or fertility concerns.

What tests can help me learn more about Thyroid and FOXE1 rs965513?

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.