It is also notable that, of the original 143 eligible participants, only 75 completed this research. Of those who left the cohort, 6 (4%) had discontinued cross-sex hormone treatment and 27 (19%) could not be reached. These figures are consistent with high loss to follow up in other studies of so-called “gender-affirming care.”  

1. van der Loos MATC, Vlot MC, Klink DT, Hannema SE, den Heijer M, Wiepjes CM. Bone Mineral Density in Transgender Adolescents Treated With Puberty Suppression and Subsequent Gender-Affirming Hormones. JAMA Pediatrics. 2023 Dec 1;177(12):1332-1341. doi: 10.1001/jamapediatrics.2023.4588. PMID: 37902760; PMCID: PMC10616766. ︎

The post Bone mineral density that declines during puberty blockade may not fully recover with cross-sex hormone treatment. appeared first on Stats for Gender.

Samples were gathered as part of “fertility preservation surgery,” in which testicular tissue is harvested and preserved in hope that it will be able to produce sperm later. Every boy with gender dysphoria in the study had elected for this surgery due to inability or reluctance to ejaculate. This suggests the possible presence of various psychological and physical conditions that are unexplored in the research.

1. Murugesh V, Ritting M, Salem S, Aalam SMM, Garcia J, Chattha AJ, Zhao Y, Knapp DJ, Kalthur G, Granberg CF, Kannan N. Puberty Blocker and Aging Impact on Testicular Cell States and Function. bioRxiv [Preprint]. 2024 Mar 27:2024.03.23.586441. Doi: 10.1101/2024.03.23.586441. PMID: 38585884; PMCID: PMC10996503. ︎

The post Boys receiving puberty blockers for gender dysphoria experienced irreversible changes to their testes. appeared first on Stats for Gender.

1. https://sex-matters.org/wp-content/uploads/2022/12/Teenagers-medication-vs-placebo.pdf ︎

The post Psychological effects of puberty blockers on young people may be worse than placebo. appeared first on Stats for Gender.

This study was conducted from 2016 to 2021 by Dr. Johanna Olson-Kennedy. In 2024, the New York Times reported² Dr. Olson-Kennedy saying that publication of this research had been delayed because she feared that research showing that puberty blockers did not improve patients’ mental health would be “weaponized” against the use of puberty blockers by opponents of the practice. The report appeared as a pre-print, not peer-reviewed, in May 2025.

1. Johanna Olson-Kennedy, Liyuan Wang, Carolyn F. Wong, Diane Chen, Diane Ehrensaft, Marco A. Hidalgo, Amy C. Tishelman, Yee-Ming Chan, Robert Garofalo, Asa E. Radix, Stephen M. Rosenthal, Emotional Health of Transgender Youth 24 Months After Initiating Gender-Affirming Hormone Therapy, Journal of Adolescent Health, Volume 77, Issue 1, 2025, Pages 41-50, ISSN 1054-139X, https://doi.org/10.1016/j.jadohealth.2024.11.014. ︎
2. https://www.nytimes.com/2024/10/23/science/puberty-blockers-olson-kennedy.html
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The post Depression symptoms got worse in children taking puberty blockers. appeared first on Stats for Gender.

1. Christopher Newton, Dianne Slota, Albert A. Yuzpe, Ian S. Tummon, Memory complaints associated with the use of gonadotropin-releasing hormone agonists: a preliminary study, Fertility and Sterility, Volume 65, Issue 6, 1996. ISSN 0015-0282. https://doi.org/10.1016/S0015-0282(16)58351-4. ︎

The post Women taking GnRH agonists for endometriosis experienced memory problems during treatment. appeared first on Stats for Gender.

In another study² of 30 children experiencing early puberty and treated with puberty blockers, IQ fell by around seven points.

1. Wojniusz S, Callens N, Sütterlin S, Andersson S, De Schepper J, Gies I, Vanbesien J, De Waele K, Van Aken S, Craen M, Vögele C, Cools M, Haraldsen IR. Cognitive, Emotional, and Psychosocial Functioning of Girls Treated with Pharmacological Puberty Blockage for Idiopathic Central Precocious Puberty. Frontiers in Psychology. 2016 Jul 12;7:1053. doi: 10.3389/fpsyg.2016.01053. PMID: 27462292; PMCID: PMC4940404. ︎
2. Mul D, Versluis-den Bieman HJ, Slijper FM, Oostdijk W, Waelkens JJ, Drop SL. Psychological assessments before and after treatment of early puberty in adopted children. Acta Paediatrica. 2001 Sep;90(9):965-71. doi: 10.1080/080352501316978011. PMID: 11683207. ︎

The post The IQ of girls given puberty blockers for precocious puberty fell by eight points. appeared first on Stats for Gender.

Verbal comprehension showed a continuous decline. Other measurements showed some improvement after an initial decline, but never recovered to baseline levels. Processing speed index scores initially improved, but then fell below baseline.

1. Schneider MA, Spritzer PM, Soll BMB, Fontanari AMV, Carneiro M, Tovar-Moll F, Costa AB, da Silva DC, Schwarz K, Anes M, Tramontina S, Lobato MIR. Brain Maturation, Cognition and Voice Pattern in a Gender Dysphoria Case under Pubertal Suppression. Frontiers in Human Neuroscience. 2017 Nov 14;11:528. doi: 10.3389/fnhum.2017.00528. PMID: 29184488; PMCID: PMC5694455. ︎

The post IQ fell in a male patient whose puberty was blocked due to gender distress. appeared first on Stats for Gender.

1. Baxendale S. The impact of suppressing puberty on neuropsychological function: a review. Acta Paediatrica. 2024; 113(6): 1156-1167. doi:10.1111/apa.17150 ︎

The post Animal studies suggest puberty blockers may impair brain development, sometimes irrevocably. appeared first on Stats for Gender.

The highest rate of deterioration (34%) was recorded at the 12 month evaluation, when the sample size was at its largest. Evaluations at 24 and 36 months were affected by significant loss to follow-up, which compromises the data.

1. McPherson, S., & Freedman, D. E. P. (2023). Psychological Outcomes of 12–15-Year-Olds with Gender Dysphoria Receiving Pubertal Suppression in the UK: Assessing Reliable and Clinically Significant Change. Journal of Sex & Marital Therapy, 50(3), 315–325. https://doi.org/10.1080/0092623X.2023.2281986 ︎

The post More patients on puberty blockers saw their distress deteriorate than improve. appeared first on Stats for Gender.

This study is compromised by the lack of follow-up once patients reached the age of 16, meaning there were significant effective drop-out rates at 24 and 36 months.

1. Carmichael P, Butler G, Masic U, Cole TJ, De Stavola BL, Davidson S, Skageberg EM, Khadr S, Viner RM. Short-term outcomes of pubertal suppression in a selected cohort of 12 to 15 year old young people with persistent gender dysphoria in the UK. PLoS One. 2021 Feb 2;16(2):e0243894. doi: 10.1371/journal.pone.0243894. PMID: 33529227; PMCID: PMC7853497. ︎

The post Rates of suicidality and self-harm did not improve in teenagers taking puberty blockers. appeared first on Stats for Gender.

1. Carmichael P, Butler G, Masic U, Cole TJ, De Stavola BL, Davidson S, Skageberg EM, Khadr S, Viner RM. Short-term outcomes of pubertal suppression in a selected cohort of 12 to 15 year old young people with persistent gender dysphoria in the UK. PLoS One. 2021 Feb 2;16(2):e0243894. doi: 10.1371/journal.pone.0243894. PMID: 33529227; PMCID: PMC7853497. ︎

The post The height of teenagers taking puberty blockers did not increase at an age-appropriate rate. appeared first on Stats for Gender.

This study is compromised by the lack of follow-up once patients reached the age of 16, meaning there were significant effective drop-out rates at 24 and 36 months.

1. Carmichael P, Butler G, Masic U, Cole TJ, De Stavola BL, Davidson S, Skageberg EM, Khadr S, Viner RM. Short-term outcomes of pubertal suppression in a selected cohort of 12 to 15 year old young people with persistent gender dysphoria in the UK. PLoS One. 2021 Feb 2;16(2):e0243894. doi: 10.1371/journal.pone.0243894. PMID: 33529227; PMCID: PMC7853497. ︎

The post Teenagers taking puberty blockers report more negative mood changes over time. appeared first on Stats for Gender.

This study is compromised by the lack of follow-up once patients reached the age of 16, meaning there were significant effective drop-out rates at 24 and 36 months.

1. Carmichael P, Butler G, Masic U, Cole TJ, De Stavola BL, Davidson S, Skageberg EM, Khadr S, Viner RM. Short-term outcomes of pubertal suppression in a selected cohort of 12 to 15 year old young people with persistent gender dysphoria in the UK. PLoS One. 2021 Feb 2;16(2):e0243894. doi: 10.1371/journal.pone.0243894. PMID: 33529227; PMCID: PMC7853497. ︎

The post The bone mineral density of teenagers taking puberty blockers did not increase to age-appropriate levels appeared first on Stats for Gender.

This study is compromised by the lack of follow-up once patients reached the age of 16, meaning there were significant effective drop-out rates at 24 and 36 months.

1. Carmichael P, Butler G, Masic U, Cole TJ, De Stavola BL, Davidson S, Skageberg EM, Khadr S, Viner RM. Short-term outcomes of pubertal suppression in a selected cohort of 12 to 15 year old young people with persistent gender dysphoria in the UK. PLoS One. 2021 Feb 2;16(2):e0243894. doi: 10.1371/journal.pone.0243894. PMID: 33529227; PMCID: PMC7853497. ︎

The post Puberty blockers did not improve psychological functioning of GIDS patients. appeared first on Stats for Gender.

1. Little Athletics Australia. (2018). Australian best performances as at August 2018 [PDF]. https://www.littleathletics.com.au/wp-content/uploads/2019/03/ABP-as-at-August-2018-V1.pdf
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The post Boys show a clear athletic advantage over girls even before puberty. appeared first on Stats for Gender.

1. Baxendale, S. (2024). The impact of suppressing puberty on neuropsychological function: A review. Acta Paediatrica, 113(7), 1156-1167. [Link] ︎

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This finding aligns with the previous 2020 review by the British National Institute for Clinical Excellence (NICE) on puberty blockers², which described the supporting evidence as “very low” quality. The review noted minimal changes in key outcomes like gender dysphoria, mental health, and quality of life due to small, uncontrolled observational studies. Furthermore, a 2024 review from Germany by Zepf et al.³, adhering to NICE criteria, confirmed the absence of new studies on puberty blockers for gender dysphoria since the NICE review.

1. Taylor, J., Mitchell, A., Hall, R., Heathcote, C., Langton, T., Fraser, L., & Hewitt, C. E. (2024). Interventions to suppress puberty in adolescents experiencing gender dysphoria or incongruence: a systematic review. Archives of disease in childhood, archdischild-2023-326669. [Link]  ︎
2. National Institute for Health and Care Excellence (2021). Evidence review: Gonadotrophin releasing hormone analogues for children and adolescents with gender dysphoria. National Institute for Health and Care Excellence (NICE); NHS England; NHS Improvement. [Link] ︎
3. Zepf, F. D., König, L., Kaiser, A., Ligges, C., Ligges, M., Roessner, V., … & Holtmann, M. (2024). Beyond NICE: Aktualisierte systematische Übersicht zur Evidenzlage der Pubertätsblockade und Hormongabe bei Minderjährigen mit Geschlechtsdysphorie. Zeitschrift für Kinder-und Jugendpsychiatrie und Psychotherapie. [Link] ︎

The post There is no high-quality evidence supporting the use of puberty blockers for gender distress appeared first on Stats for Gender.

1. Ma, L., Tan, E. C., Goudey, B., Jin, L., & Pan, Y. (2025). Unraveling the bidirectional link between cancer and dementia and the impact of cancer therapies on dementia risk: A systematic review and meta‐analysis. Alzheimer’s & Dementia, e14540. [Link] ︎

The post Suppressing sex hormones in males, using treatments like those prescribed as puberty blockers, is linked to an increased risk of dementia appeared first on Stats for Gender.

Suppression of puberty with gonadotropin-releasing hormone agonist analogs (GnRHa) in the pediatric transgender patient can pause the maturation of germ cells, and thus, affect fertility potential. Testosterone therapy in transgender men can suppress ovulation and alter ovarian histology, while estrogen therapy in transgender women can lead to impaired spermatogenesis and testicular atrophy. The effect of hormone therapy on fertility is potentially reversible, but the extent is unclear.

On surgeries, the study noted that cross-sex surgery that includes hysterectomy and oophorectomy in transmen or orchiectomy in transwomen results in permanent sterility.

1. Cheng, P.J., Pastuszak, A.W., Myers, J.B., Goodwin, I.A. & Hotaling, J.M. (2019). Fertility concerns of the transgender patient. Transl Androl Urol. 8 (3): 209-218. [Link] ︎

The post Medical transition puts both males and females at risk of infertility appeared first on Stats for Gender.

However, as expected, the children experienced reduced growth in height and bone strength by the time they finished their treatment at age 16.

1. Carmichael, P., Butler, G., Masic, U., Cole, T. J., De Stavola, B. L., Davidson, S., Skageberg, E. M., Khadr, S., & Viner, R. M. (2021). Short-term outcomes of pubertal suppression in a selected cohort of 12 to 15 year old young people with persistent gender dysphoria in the UK. PLOS ONE 16 (2). [Link] ︎

The post One study found that puberty blockers did not alleviate negative thoughts in children with gender dysphoria appeared first on Stats for Gender.