Myo-inositol + Selenium (combo)

What It Is

Myo-inositol is a naturally occurring compound—technically a carbohydrate—found in many foods such as fruits, beans, grains, and nuts. It is a structural basis for several secondary messengers in cells and plays a major role in insulin signaling, nerve function, and cell membrane health. It is often referred to as “vitamin B8,” although it is not an essential vitamin because the body can synthesize it.

Selenium is a trace mineral essential for numerous biological processes. It acts mainly through its incorporation into selenoproteins, which function as antioxidants and enzymes supporting thyroid function, immune health, and reproduction. Selenium is found in foods like Brazil nuts, seafood, meat, and eggs.

When combined, Myo-inositol and Selenium are frequently used as a therapeutic supplement for supporting thyroid health and female reproductive function, particularly in conditions such as polycystic ovary syndrome (PCOS) and subclinical hypothyroidism.

How It Works

1. Hormonal and Metabolic Regulation (Myo-inositol): Myo-inositol acts as a key component in insulin signal transduction pathways. It helps cells respond properly to insulin, improving glucose uptake and reducing insulin resistance. In women with PCOS, this can normalize ovulatory cycles, lower testosterone levels, and support fertility.
2. Thyroid Function and Antioxidant Protection (Selenium): Selenium is crucial for the proper functioning of thyroid peroxidase and deiodinase enzymes, which are involved in thyroid hormone synthesis and conversion (e.g., T4 to T3). It also protects thyroid tissue from oxidative damage through antioxidant selenoproteins like glutathione peroxidase.
3. Synergistic Effect on the Thyroid: The combination of Myo-inositol and Selenium has been shown to reduce thyroid-stimulating hormone (TSH) levels and improve thyroid autoantibody profiles in autoimmune thyroiditis (such as Hashimoto’s thyroiditis). Myo-inositol supports signaling pathways in thyroid cells, while selenium mitigates oxidative stress, together contributing to better thyroid regulation.
4. Reproductive Health Benefits: In reproductive contexts, the combo supports oocyte quality, menstrual regularity, and fertility. Myo-inositol enhances insulin sensitivity in ovarian tissue, while selenium supports antioxidant balance and hormone metabolism in reproductive organs.

Why It’s Important

1. Supports Thyroid Health: Optimal selenium status is vital for preventing thyroid inflammation and maintaining hormone balance. Myo-inositol complements this by optimizing intracellular signaling, aiding in the regulation of TSH secretion.
2. Improves Metabolic Health: In individuals with metabolic syndrome or PCOS, Myo-inositol enhances insulin sensitivity and reduces hyperandrogenism, which helps improve symptoms like irregular periods, acne, and weight gain.
3. Enhances Fertility and Reproductive Outcomes: The combination is used to promote ovulation and improve oocyte (egg) quality in women undergoing fertility treatment. Selenium’s antioxidant role further protects ovarian cells from oxidative stress.
4. Supports Overall Antioxidant Defense: Selenium’s inclusion ensures that oxidative damage—often elevated in hormonal and metabolic disorders—is mitigated, supporting cellular integrity across multiple systems.

Considerations

Dosage:

• Common clinical formulations contain around 600 mg Myo-inositol with 83 µg Selenium daily, though dosage may vary depending on the specific product and therapeutic goal. Always follow medical guidance for individualized dosing.

Potential Side Effects:

• Myo-inositol is generally well tolerated; mild gastrointestinal discomfort may occur at high doses. Selenium, however, can be toxic at high levels—chronic intake above 400 µg/day may lead to selenosis (symptoms include hair loss, nail brittleness, and nervous system issues).

Interactions:

• Selenium supplementation should be used cautiously with other antioxidants or mineral supplements to avoid excessive accumulation.
• Individuals already taking thyroid medication (e.g., levothyroxine) should consult their doctor before starting, as it can influence thyroid function tests.

Population Considerations:

• Pregnancy and fertility: Safe and often beneficial under medical supervision.
• Thyroid disorders: Beneficial in autoimmune thyroiditis, but dosage must be closely monitored.
• Metabolic conditions: Helpful for PCOS, insulin resistance, and prediabetes management.

Quality and Form:

• Choose supplements from reputable manufacturers with clear ingredient transparency. Selenium is best absorbed in organic forms such as selenomethionine.