Thank you to everyone who attended my Selective Estrogen Receptor Modulator (SERM) lecture for Trans Care BC. Below are the resources and references we discussed during and after the session. I hope they're helpful as you continue exploring this evolving area of gender affirming care.

Raloxifene vs. Puberty Blockers

Clinicians asked about the role of raloxifene compared with GnRH agonists (puberty blockers) in transgender and gender diverse adolescents. When I discuss raloxifene with patients and families, I typically begin with a broad overview during the clinical visit, then ask them to review the article below before a follow-up conversation. The article is written for patients and families and serves as a foundation for shared decision-making—not as a recommendation for treatment. 

During our follow-up visit, we review questions and discuss the many uncertainties surrounding SERMs in gender affirming care, including the lack of FDA-approved indications for this use, the limited evidence base, the absence of long-term research in transgender and gender diverse populations, and whether raloxifene aligns with the individual's goals, anatomy, values, and barriers to care.

Patient & Family Resource: Raloxifene vs. Puberty Blockers in Adolescents with Ovaries

Evidence on Breast Size Reduction

Several people asked about evidence supporting raloxifene for reducing breast tissue.

One of the most frequently cited studies is:

Lawrence SE, et al. Beneficial effects of raloxifene and tamoxifen in the treatment of pubertal gynecomastia.

Key findings:

• Mean breast nodule diameter decreased by 2.5 cm with raloxifene.

• 91% of participants experienced some improvement.

• 86% had greater than 50% reduction in breast nodule size.

• No significant adverse effects were reported during treatment.

As discussed during the lecture, these findings are from adolescents with pubertal gynecomastia and should not be directly extrapolated to transgender patients.

Additional Resources

If you'd like to continue learning about transgender medicine with Dr. Beal and other guest educators:

• Free QueerCME preview

• Free podcast episodes

• Artwork by Liberal Jane

Healthcare professionals who complete accredited QueerCME activities earn AMA PRA Category 1 Credit™. Eligible Royal College of Physicians and Surgeons of Canada participants may claim these activities for MOC credit in accordance with Royal College guidance.

References

Below are the references shared during the lecture for anyone who would like to read further. They include foundational reviews of SERMs, studies on gynecomastia, osteoporosis, prostate cancer, McCune-Albright syndrome, and emerging literature on the role of SERMs in transgender and nonbinary care.

• Martinkovich, Stephen & Shah, Darshan & Lobo, Sonia & Arnott, John. (2014). Selective estrogen receptor modulators: tissue specificity and clinical utility. Clinical Interventions in Aging. 9. 1437-1452. 10.2147/CIA.S66690. 
• Duschek EJ, Gooren LJ, Netelenbos C. Effects of raloxifene on gonadotrophins, sex hormones, bone turnover and lipids in healthy elderly men. Eur J Endocrinol. 2004 Apr;150(4):539-46. doi: 10.1530/eje.0.1500539. PMID: 15080785.
• Uebelhart B, Herrmann F, Pavo I, Draper MW, Rizzoli R. Raloxifene treatment is associated with increased serum estradiol and decreased bone remodeling in healthy middle-aged men with low sex hormone levels. J Bone Miner Res. 2004 Sep;19(9):1518-24. doi: 10.1359/JBMR.040503. Epub 2004 May 3. PMID: 15312253.
• Nordt CA, DiVasta AD. Gynecomastia in adolescents. Curr Opin Pediatr. 2008 Aug;20(4):375-82. doi: 10.1097/MOP.0b013e328306a07c. PMID: 18622190.
• Lawrence SE, Faught KA, Vethamuthu J, Lawson ML. Beneficial effects of raloxifene and tamoxifen in the treatment of pubertal gynecomastia. J Pediatr. 2004 Jul;145(1):71-6. doi: 10.1016/j.jpeds.2004.03.057. PMID: 15238910.
• Kunath, F., Keck, B., Antes, G. et al. Tamoxifen for the management of breast events induced by non-steroidal antiandrogens in patients with prostate cancer: a systematic review. BMC Med 10, 96 (2012). https://doi.org/10.1186/1741-7015-10-96
• Farkas HS, Jee YH, Szymczuk V, Leschek EW. Persistent Gynecomastia due to Short-term Low-dose Finasteride for Androgenetic Alopecia. JCEM Case Rep. 2024 Apr 24;2(5):luae050. doi: 10.1210/jcemcr/luae050. PMID: 38660487; PMCID: PMC11040274
• Eugster EA, Rubin SD, Reiter EO, et al, “Tamoxifen Treatment for Precocious Puberty in McCune-Albright Syndrome: A Multicenter Trial,” J Pediatr, 2003, 143(1):60-6. [PubMed 12915825]
• Kreher NC, Eugster EA, Shankar RR. The use of tamoxifen to improve height potential in short pubertal boys. Pediatrics. 2005;116(6):1513-1515. doi:10.1542/peds.2005-0577 [PubMed 16322179]
• V. Craig Jordan; The Science of Selective Estrogen Receptor Modulators: Concept to Clinical Practice. Clin Cancer Res 1 September 2006; 12 (17): 5010–5013. https://doi-org.offcampus.lib.washington.edu/10.1158/1078-0432.CCR-06-1136
• Pang KC, Notini L, McDougall R, Gillam L, Savulescu J, Wilkinson D, Clark BA, Olson-Kennedy J, Telfer MM, Lantos JD. Long-term Puberty Suppression for a Nonbinary Teenager. Pediatrics. 2020 Feb;145(2):e20191606. doi: 10.1542/peds.2019-1606. PMID: 31974217.
• Xu JY, O'Connell MA, Notini L, Cheung AS, Zwickl S, Pang KC. Selective Estrogen Receptor Modulators: A Potential Option For Non-Binary Gender-Affirming Hormonal Care? Front Endocrinol (Lausanne). 2021 Jun 18;12:701364. doi: 10.3389/fendo.2021.701364. PMID: 34226826; PMCID: PMC8253879.
• Clark DBA, Metzger DL, Pang KC, St Amand C, Khatchadourian K. Individualized and innovative gender healthcare for transgender and nonbinary youth. Nat Rev Endocrinol. 2025 Jul;21(7):441-452. doi: 10.1038/s41574-025-01113-z. Epub 2025 May 7. PMID: 40335737.
• Lain. (2020). A Review of Selective Estrogen Receptor Modulators and their Potential for Transfeminine Hormone Therapy. Transfeminine Science. https://transfemscience.org/articles/serms-transfem/
• Ettinger B, Black DM, Mitlak BH, et al. Reduction of Vertebral Fracture Risk in Postmenopausal Women With Osteoporosis Treated With Raloxifene: Results From a 3-Year Randomized Clinical Trial. JAMA. 1999;282(7):637–645. doi:10.1001/jama.282.7.637
• Baseline characteristics of participants in the Raloxifene Use for The Heart (RUTH) trial RUTH Investigators et al. American Journal of Cardiology, Volume 90, Issue 11, 1204 - 1210
• Vogel VG, Costantino JP, Wickerham DL, et al. Effects of Tamoxifen vs Raloxifene on the Risk of Developing Invasive Breast Cancer and Other Disease Outcomes: The NSABP Study of Tamoxifen and Raloxifene (STAR) P-2 Trial. JAMA. 2006;295(23):2727–2741. doi:10.1001/jama.295.23.joc60074