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Tamoxifen citrate Reference

Educational, not medical advice reference for Tamoxifen citrate: Hormonal; regulatory status, evidence posture, source review, and schedule note…

Plain English

What it is
Tamoxifen (sold as Nolvadex and Soltamox) is a prescription medicine approved by the U.S. FDA. It is a type of drug called a SERM, which blocks the hormone estrogen's effects in some body tissues.
What people use it for
Doctors prescribe it to treat breast cancer and to lower the chance of breast cancer in people at high risk. Some people in lifting and testosterone-therapy circles also take it off-label, a use the FDA has not approved, to manage estrogen-related side effects or to help the body restart its own testosterone after anabolic-steroid use.
What the science shows
The evidence behind its approved breast-cancer uses is strong and well-studied. The off-label use in men rests on much smaller studies, and reviews point out that long-term safety data in men are still lacking.
The catch
It carries the FDA's strongest 'boxed' warning: it can cause uterine cancer, stroke, and dangerous blood clots in the lungs and legs, and some of these can be deadly. The blood-clot risk applies to men too, even those who never had a clot, and liver and vision problems are also reported. It is banned in sports, and any off-label use has no agreed-on plan and is left to a prescriber.

Reference summary

On-label breast-cancer evidence is mature. The off-label male use cases (gynecomastia treatment, HPTA-recovery contexts) have small randomized and case-series data; Wibowo 2016 Andrology reviewed adverse events in men. Tamoxifen has documented thromboembolic risk in women and the same class concern applies to off-label male use.

Regulatory and posture

Categories
Hormonal
Aliases
Nolvadex, Soltamox, Selective estrogen receptor modulator (small molecule, not a peptide)
Evidence posture
human - Off-label male gynecomastia and HPTA-recovery use is investigational. Thromboembolic risk is real even in men. Hepatotoxicity at high doses.
Regulatory status
FDA-approved for the treatment of metastatic breast cancer, adjuvant treatment of breast cancer, and reduction in breast-cancer incidence in high-risk women. Off-label use in men for treatment of gynecomastia and HPTA-recovery contexts after anabolic-androgenic-steroid exposure exists in clinical practice but is not an FDA-approved indication. WADA-prohibited at all times under S4.
Content review status
label verified

Selected public sources

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