● Drugs that can increase T3 measurements include: birth control pills, clofibrate, estrogens, Methadone.
● Drugs that can decrease T3 measurements include: amiodarone, anabolic steroids, androgens, anti-thyroid drugs (for example, propythiouracil and methimazole), lithium, phenytoin, beta-blockers (propanolol).
● Factors that causes an inability to convert T4 to T3, leading to a preferential conversion to reverse-T3:
○ Nutrient deficiencies: Iodine, Iron, Selenium, Zinc, Vitamin A, B2, B6, B12.
○ Medications: beta blockers, birth control pills, estrogen, iodinated contrasts agents, lithium, steroids, phenyltoin, theophylline.
○ Goitrogenic food: cruciferous vegetables, soy products.
○ Other factors: aging, alcohol, alpha-lipoic acid, diabetes, fluoride, lead, mercury, pesticides, radiation, stress and surgery.