Tamoxifen
Also known as: Nolvadex, Tamoxifen citrate
A selective estrogen receptor modulator (SERM) used off-label to manage gynecomastia and in post-cycle therapy. Prescription medication (approved for breast cancer).
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Mechanism of Action
Tamoxifen blocks estrogen receptors in breast tissue (acting as an anti-estrogen there) while behaving as an estrogen agonist in bone and liver. At the pituitary it blocks estrogen negative feedback, raising LH and FSH and therefore endogenous testosterone — which is why it is used both to prevent/treat gynecomastia and to restart the HPG axis in post-cycle therapy. It does not lower total estradiol the way an aromatase inhibitor does.
- Half-life
- ~5-7 days
- Administration Routes
- Oral
- Research Status
- Clinical
Reported Benefits
- Prevents and reduces estrogen-related gynecomastia
- Raises endogenous testosterone in post-cycle therapy
- Favorable effect on bone density
Potential Side Effects
- Hot flashes, mood changes
- Increased thromboembolic (clot) risk — a SERM class effect
- Nausea; rare visual disturbance
Common Dosing
Off-label gynecomastia and PCT protocols use a low oral daily dose. Physician-directed; the clot risk means it is not a casual supplement.
The dosing information above is aggregated from research literature and anecdotal community reports for educational purposes only. It is not a recommendation, prescription, or medical advice. Peptides are sold as research chemicals only and are not intended for human use.
Contraindications
- History of blood clots / thromboembolism
- Hormone-sensitive conditions
- Pregnancy
- Use only under medical supervision
Clomiphene
A selective estrogen receptor modulator (SERM) used off-label to raise endogenous testosterone and to restart natural production in post-cycle therapy. Prescription medication (approved for female fertility).
HCG (Human Chorionic Gonadotropin)
A glycoprotein hormone produced in pregnancy that mimics luteinizing hormone, used clinically to stimulate gonadal function. It is studied to support testosterone production and fertility.
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Tamoxifen in men: a review of adverse events
2016
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Prevention and management of bicalutamide-induced gynecomastia and breast pain: randomized endocrinologic and clinical studies with tamoxifen and anastrozole
2005
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The effect of selective estrogen receptor modulator administration on the hypothalamic-pituitary-testicular axis in men with idiopathic oligozoospermia
2009
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Long-term effects of continuing adjuvant tamoxifen to 10 years versus stopping at 5 years after diagnosis of oestrogen receptor-positive breast cancer: ATLAS, a randomised trial
2013