Tamoxifen

Research records

Historical source snapshot. Not freshly verified, not a recommendation. Study findings, community accounts and app defaults are not interchangeable.

Publication suitability · 2026-10-15: Historical reference only; not a clinical verification. Clinical, regulatory, efficacy, safety and dose claims are not independently established by this review.

Tamoxifen

An FDA-approved selective estrogen receptor modulator used to treat hormone receptor-positive breast cancer.

Evidence category: Regulator / guideline. This describes the source category, not approval or certainty.

Regulatory statement in source: FDA-approved.

Tamoxifen was the first selective estrogen receptor modulator (SERM) approved by the FDA in 1977. It reduces cancer recurrence risk by 50% during the first 5 years and 33% during years 5-9 in estrogen receptor-positive early breast cancer. FDA-approved for early breast cancer, ductal carcinoma in situ, and risk reduction in high-risk women.

Benefits reported in the imported source

• Reducing recurrence and death in early-stage ER+ breast cancer.
• DCIS and risk reduction in high-risk women.

Risks and limits

• Endometrial cancer risk
• Thromboembolic events
• Hot flashes
• Sexual dysfunction

Source bottom line: First SARM approved by FDA with robust evidence of benefit in hormone receptor-positive breast cancer.

Uncertainty: Reference information only. Not medical advice.

Study protocols — reports, not instructions

Community and practice descriptions

Accounts of a practice are not evidence of safety or effectiveness. Words such as “standard”, “safe” or “recommended” describe the source account, not verified consensus or this wiki’s advice. Commercial and self-published citations are retained for traceability, not vendor endorsement or independent clinical corroboration.

Pharmacokinetic context

Historical half-life estimate: 120–168 hours. FDA label, tamoxifen citrate: terminal elimination half-life 5 to 7 days Population/route context and estimates may differ. This is not a schedule or a verified human dosing rule.

Source references

• DailyMed: tamoxifen
• Use of SERMs for Adjuvant Therapy - Johns Hopkins University
• Tamoxifen - StatPearls (availability check 2026-10-15: possible access barrier; not independently inspected; HTTP 200)
• Treating ER-positive breast cancer: SERMs and SERDs review (availability check 2026-10-15: possible access barrier; not independently inspected; HTTP 200)