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Understanding Your TSHR Gene and Thyroid Health

The thyroid gland regulates metabolism, body temperature, heart function, and reproductive health by producing hormones that control many body processes. The TSHR gene encodes the thyroid-stimulating hormone receptor, a protein on thyroid cells that receives signals from the pituitary gland and tells the thyroid to make hormones. Variations in TSHR can change how well this receptor works and may influence risk for hypothyroidism, which occurs when the thyroid does not produce enough hormone.

Why this matters for health

  • Thyroid hormones affect energy, weight, heat tolerance, mood, and menstrual cycles.
  • In women, altered thyroid function can contribute to irregular periods, fertility challenges, and changes in estrogen and progesterone balance.
  • Knowing your TSHR genotype can help you and your healthcare provider tailor monitoring and lifestyle choices to support thyroid function.

Key nutrients and lifestyle factors that support thyroid health

Regardless of genotype, supporting thyroid function centers on adequate intake of specific nutrients, avoiding factors that interfere with thyroid hormone production, and regular monitoring if you are at higher risk.

  • Iodine: Required to make thyroid hormones. Get iodine from iodized salt, seafood, and dairy. Avoid excess iodine from supplements or frequent consumption of certain seaweeds.
  • Selenium: Needed for conversion of thyroid hormones and antioxidant protection of the gland. Sources include Brazil nuts (1 to 2 small nuts daily is often sufficient), seafood, eggs, and mushrooms.
  • Vitamin A: Supports thyroid hormone action and metabolism. Eat colorful vegetables and liver in moderation if appropriate.
  • Zinc: Helps regulate the thyroid hormone pathway. Found in oysters, red meat, poultry, beans, and nuts.
  • Vitamin D: Many people are low in vitamin D. Adequate levels support immune and endocrine health. Check blood 25(OH)D and consider supplementation if low.
  • Melatonin: Proper sleep and circadian rhythm support hormonal balance. Avoid light at night and prioritize consistent sleep patterns.
  • Diet considerations: Moderate intake of soy and raw cruciferous vegetables if you have thyroid dysfunction. Cooking cruciferous vegetables reduces their potential to interfere with iodine uptake. Avoid very high intakes of kelp and other iodine-rich seaweeds.
  • Environmental factors: Reduce exposure to endocrine disruptors such as certain plastics, pesticides, and heavy metals. Regular testing for thyroid function helps identify changes early.

Clinical monitoring and testing

Regular thyroid testing is an important tool. Typical tests include TSH, free T4, free T3, and in some cases thyroid peroxidase antibodies. If you have symptoms or a higher genetic risk, work with your healthcare provider to set an appropriate testing schedule.

Genetic Interpretation for rs1991517 (TSHR)

2 effect alleles (GG) — Increased risk of hypothyroidism

Your genotype: GG. You carry two copies of the effect allele. This pattern is associated with an increased risk of hypothyroidism. The TSHR gene instructs cells how to build the thyroid-stimulating hormone receptor. With the GG genotype, receptor signaling to the thyroid may be less efficient, which can reduce thyroid hormone production over time.

Potential health effects

  • Lower energy, slower metabolism, weight gain, cold intolerance, and dry skin.
  • In women, possible menstrual irregularities, fertility challenges, and shifts in estrogen and progesterone balance.
  • Higher likelihood of developing clinical hypothyroidism or needing closer monitoring of thyroid function.

Recommendations

  • Schedule baseline thyroid testing and repeat testing periodically or if symptoms emerge. Include TSH and free T4 at minimum.
  • Optimize iodine and selenium through food. Limit high-dose iodine supplements unless directed by your provider.
  • Ensure vitamin D sufficiency. Check 25(OH)D and supplement if deficient.
  • Include selenium-rich foods like Brazil nuts (1 to 2 small nuts daily), seafood, and eggs.
  • Be mindful of environmental exposures. Reduce use of plastics with BPA, minimize pesticide residues, and avoid heavy metal exposure where possible.
  • Discuss fertility or menstrual concerns with your healthcare provider and consider earlier endocrine referral if problems arise.
1 effect allele (CG) — Likely increased risk of hypothyroidism

Your genotype: CG. You carry one copy of the effect allele. This genotype is associated with a likely increased risk of hypothyroidism. The G allele may subtly influence thyroid-stimulating hormone receptor signaling, which can translate into altered thyroid hormone levels over time.

Potential health effects

  • Possible symptoms include fatigue, changes in weight or temperature sensitivity, and menstrual changes in women.
  • Increased susceptibility to underactive thyroid function, though many people with this genotype maintain normal thyroid function.

Recommendations

  • Monitor thyroid function with periodic TSH and free T4 testing, especially if you experience symptoms.
  • Support thyroid health with dietary selenium and iodine from food sources. Include seafood, eggs, and a small number of Brazil nuts weekly.
  • Ensure adequate zinc and vitamin A from a balanced diet with colorful vegetables, lean proteins, and nuts.
  • Consider cooking cruciferous vegetables to reduce potential goitrogenic effects if you develop thyroid issues.
  • Maintain healthy sleep patterns to support melatonin and overall hormone balance.
0 effect alleles (CC) — Typical TSHR function

Your genotype: CC. You carry two copies of the non-effect allele. This genotype is associated with typical TSHR function and is not linked to the increased risk of hypothyroidism associated with the G allele. Your receptor signaling between the pituitary and the thyroid is expected to function within the usual range.

Potential health effects

  • Lower genetic predisposition from this variant toward hypothyroidism.
  • Thyroid function can still be affected by other genes, autoimmune conditions, nutritional status, medications, and environmental exposures.

Recommendations

  • Maintain a nutrient-rich diet with adequate iodine, selenium, zinc, and vitamin A from whole foods.
  • Keep vitamin D in the optimal range and sleep well to support hormonal balance.
  • Perform routine thyroid testing as part of general health care or if symptoms arise, and avoid high-dose iodine supplements without medical guidance.
  • Minimize exposure to endocrine disruptors and prioritize a healthy lifestyle to protect long-term thyroid and reproductive health.

Supplements and practical tips

  • Do not start iodine or selenium supplements without discussing with a healthcare provider. Excessive iodine can worsen some thyroid conditions.
  • If vitamin D is low, supplementation under provider guidance can support immune and endocrine health.
  • Prioritize whole foods: seafood, lean meats, eggs, nuts, dairy if tolerated, and colorful vegetables supply key micronutrients.
  • Manage stress and sleep. Chronic stress and disrupted sleep can influence hormone balance and thyroid function.
  • If you are trying to conceive or have menstrual irregularities, share your genetic result and thyroid test results with your reproductive healthcare provider.

Important note

PlexusDx provides genetic information to help you understand potential predispositions. This content is educational and not medical advice. Always consult your healthcare provider before making changes to your diet, supplements, or medical care. Your provider can interpret genetic results alongside clinical tests, symptoms, and medical history to guide personalized care.