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Understanding LIN28B and Testosterone

Testosterone is a key hormone that supports muscle mass, strength, mood, libido, and bone health. The LIN28B gene helps regulate timing of puberty and testosterone production. One common genetic variant near LIN28B, called rs7759938, is associated with differences in average testosterone levels and puberty timing. Carrying the C allele at this location tends to be linked with lower total and free testosterone compared with the T allele. This is a genetic predisposition, not a diagnosis.

How genetics relate to health

  • Genetic variants can shift your average hormone levels but do not determine your health destiny.
  • Lifestyle, nutrition, sleep, activity, and environmental exposures play a large role in how genes are expressed and how hormones perform.
  • Testing and personalized care from a healthcare provider are important when symptoms or lab abnormalities occur.

Practical ways to support healthy testosterone

Whether your genetic test shows a predisposition toward lower testosterone or not, these evidence-based lifestyle and dietary approaches can help support healthy hormone balance and overall wellbeing.

Nutrition

  • Prioritize protein: Include lean meats, fish, eggs, dairy, and plant proteins such as legumes to support muscle repair and testosterone production.
  • Include healthy fats: Monounsaturated and omega-3 fats from olive oil, avocados, nuts, seeds, and fatty fish (salmon, mackerel) support hormone synthesis.
  • Focus on micronutrients: Zinc and magnesium are important for normal testosterone levels. Eat nuts, seeds, leafy greens, whole grains, beans, shellfish, and lean red meat where appropriate.
  • Adopt an anti-inflammatory Mediterranean-style pattern: Emphasize vegetables, fruits, whole grains, fish, and olive oil while limiting processed foods and excess sugar.
  • Limit alcohol: Excessive alcohol intake can suppress testosterone production.

Exercise and body composition

  • Strength training: Regular resistance exercise increases muscle mass and supports testosterone. Aim for 2–4 sessions per week focusing on compound movements.
  • Manage body fat: Elevated body fat, particularly central adiposity, can lower free testosterone. Combine resistance training and aerobic activity with dietary changes to improve body composition.
  • Avoid excessive endurance training without adequate recovery, which can lower testosterone in some people.

Sleep and circadian health

  • Aim for 7–8 hours of quality sleep per night. Poor sleep is strongly linked to lower testosterone.
  • Seek morning sunlight exposure to help synchronize circadian rhythms and support hormonal balance.

Environmental and lifestyle considerations

  • Reduce exposure to endocrine-disrupting chemicals: Limit use of plastics for food storage and heating, especially polycarbonate and BPA-containing items.
  • Use glass or stainless steel containers for food and beverages when possible.
  • Maintain a balanced stress-management routine: chronic stress and high cortisol can negatively affect testosterone.

Supplements and mineral status

Supplements can be helpful when dietary intake or blood tests show deficiencies. Always consult your healthcare provider before starting supplements, especially if you take medications or have medical conditions.

  • Zinc and magnesium: Consider supplementation if dietary intake is low or labs indicate deficiency.
  • Consider vitamin D if deficient: Vitamin D insufficiency is common and can be associated with lower testosterone; check levels before supplementing.
  • Herbal supplements: Some people consider ashwagandha, shilajit, or boron. Discuss risks, benefits, dose, and interactions with your provider before use.

When to check lab tests and seek care

  • If you have symptoms such as persistent low energy, reduced libido, loss of muscle mass, or mood changes, speak with a healthcare provider about evaluation.
  • Important tests may include total and free testosterone, sex hormone binding globulin (SHBG), luteinizing hormone (LH), follicle-stimulating hormone (FSH), and vitamin D, zinc, and magnesium levels as indicated.
  • Interpretation of hormone tests depends on age, time of day, and clinical context. Your healthcare provider can help interpret results and guide next steps.

Genetic interpretation for rs7759938 (LIN28B)

The section below explains what each genotype at rs7759938 means for average testosterone tendencies and practical steps you can take. This is educational information only.

2 effect alleles (CC)

Having the CC genotype means you carry two copies of the C allele associated with lower average free and total testosterone compared with other genotypes. This genetic pattern has been linked with a tendency toward modestly lower testosterone and later puberty timing.

Potential impacts

  • Possible lower muscle mass and strength compared with peers with higher genetic testosterone tendency
  • Potential for reduced energy, libido, or mood in some people
  • Small increased risk for lower bone density over time if testosterone is chronically low

Actions to consider

  • Follow a high-protein diet with lean meats, fish, eggs, legumes, and dairy
  • Ensure zinc and magnesium intake from nuts, seeds, leafy greens, and whole foods; supplement if lab tests show deficiency
  • Prioritize 7–8 hours of sleep and morning light exposure
  • Include healthy fats such as olive oil and fatty fish
  • Engage in regular strength training and aim to improve body composition
  • Limit plastic exposure and follow an anti-inflammatory Mediterranean-style diet with limited alcohol
  • Consult a healthcare provider about labs and before trying supplements like ashwagandha, shilajit, or boron
1 effect allele (CT)

The CT genotype means you carry one C allele and one T allele, which is associated with a modest tendency toward lower free testosterone compared with TT. This represents a mild genetic influence rather than a certainty of low testosterone.

Potential impacts

  • Small tendency for slightly reduced testosterone-related traits in some people
  • Symptoms are not guaranteed and depend on lifestyle and health factors

Actions to consider

  • Prioritize adequate protein sources: lean meats, fish, eggs, legumes
  • Make sure zinc and magnesium come from foods like nuts, seeds, and leafy greens
  • Aim for good sleep hygiene (7–8 hours) and morning sunlight
  • Include healthy fats and regular strength training
  • Reduce exposure to plastics and follow an anti-inflammatory diet; limit alcohol
  • Discuss testing and supplements with your healthcare provider if you have symptoms
0 effect alleles (TT)

The TT genotype means you carry two T alleles and do not carry the C variant linked to lower testosterone. On average, people with the TT genotype have typical or higher average testosterone levels related to this specific genetic site.

Potential impacts

  • No increased genetic tendency from this variant toward reduced testosterone or delayed puberty
  • Typical hormone regulation related to this locus, though other genes and factors still matter

Actions to consider

  • Continue healthy habits to maintain hormone balance: balanced protein, healthy fats, micronutrient-rich foods
  • Maintain regular strength training, sufficient sleep, and low exposure to endocrine disruptors
  • Monitor symptoms and speak with a provider if concerns arise

Important notes and next steps

PlexusDx provides educational genetic information to help you understand predispositions and to support conversations with your healthcare provider. This information is not medical advice. If you have symptoms or laboratory concerns, consult your healthcare provider for personalized evaluation, testing, and treatment options before starting supplements or making major health changes.