Anastrozole is a drug that blocks the conversion of testosterone to estrogen. It was originally developed to treat breast cancer in women, but is also used in men to control estrogen levels during testosterone therapy or in cases of excessive aromatization. Elevated estrogen in men may lead to gynecomastia, fluid retention, and suppression of natural testosterone production. Anastrozole helps maintain a proper androgen-to-estrogen balance and supports hormonal stability. Main Effects Reduces estradiol levels in the blood; Prevents gynecomastia and estrogen-related side effects; Maintains a healthy testosterone-to-estrogen ratio; Reduces fluid retention and edema; May increase endogenous testosterone via LH and FSH stimulation Administration Oral administration; Typically started 1–2 weeks after beginning an androgen cycle; May be initiated earlier (5–7 days) when using short esters or strongly aromatizing compounds; Blood testing for estradiol and testosterone is recommended before initiation Dosage 0.5 mg every other day - standard preventive dose; 0.5 mg twice per week - for moderate aromatization or TRT; 1 mg every other day - only in cases of significantly elevated estradiol (>40 pg/mL); Dosage should be adjusted based on laboratory results and individual response Duration Used throughout the androgen cycle; May be continued for 2–4 weeks after the cycle if estradiol remains elevated; Discontinued once hormonal balance is restored Compatibility Can be combined with testosterone preparations (enanthate, cypionate, sustanon); Compatible with hCG; May be used with post-cycle therapy agents (clomiphene, tamoxifen) under medical supervision; Not recommended to combine with other aromatase inhibitors (letrozole, exemestane) Precautions Use only after hormone testing; Avoid use without clear indication; Excess estrogen suppression may cause joint pain, mood decline, and reduced bone density; Requires monitoring when combined with hormonal agents; Contraindicated in premenopausal women Side Effects Joint pain or stiffness; Increased cholesterol levels; Reduced libido and fatigue; Mood changes or irritability; Possible decrease in bone density with long-term use Contraindications Hypersensitivity to anastrozole; Pregnancy and breastfeeding; Premenopausal women without medical indication Storage Store in a dry, dark place at temperatures up to 25 °C; Protect from moisture; Keep out of reach of children Mechanism of Action Anastrozole inhibits the aromatase enzyme responsible for converting testosterone into estradiol. By blocking this pathway, estrogen levels decrease while androgen levels relatively increase, reducing estrogen-related effects and stabilizing hormonal balance. Pharmacological Profile Half-life: approximately 40–50 hours; Allows dosing once daily or every other day; Provides stable suppression of estrogen levels; Widely used in both clinical and performance-related hormonal management