Press kit · Last reviewed 2026-05-16

Press kit

For journalists, editorial offices and researchers: key figures, key claim, background sources and contact information.

Key claim of this dossier

The Dutch Protocol — a phased pathway with puberty blockers, cross-sex hormones and surgery in adolescents — is built on one Dutch cohort study (n=55, 2014) without a control group and without randomised verification. On that basis it has been applied worldwide to tens of thousands of minors. Independent evaluators (NICE 2020, SBU 2022, COHERE 2020, Cass 2024, Ukom 2023) classify the evidence base as "very low certainty". The Netherlands — the country of origin — is the only originator that has not yet conducted an independent evidence review.

Key figures

Figure	Context
1987	First GnRHa treatment in a 13-year-old adolescent (VUmc), without a formal protocol
1998	First publication (Cohen-Kettenis & van Goozen) — case report
2006	Formal protocol description (Delemarre & Cohen-Kettenis)
n = 70	First follow-up study (de Vries 2011)
n = 55	"Amsterdam study" (de Vries 2014) — the global evidence base
0	RCTs supporting the protocol
96–98%	Continuation from GnRHa to CSH — "diagnostic pause" does not exist
~7.8%	ASD comorbidity in original VUmc cohort; many times higher internationally
5,000+	Referrals per year to Tavistock GIDS (UK) at peak 2021/22
2024-03	NHS England withdraws routine GnRHa reimbursement
2024-04	Cass Review final report — international turn
2022-2027	ZonMw research programme on transgender care NL (ongoing)

Topics on which this site supplies sources

The protocol — what it claims, and what the assumptions really are.
Scientific basis — the narrow evidence base exposed.
Evaluations — Cass, SBU, COHERE, Karolinska, Ukom, Florida, Levine, WPATH Files.
International rollout + comparative table.
Criticism, harm, legal battles.
Timeline · People index · Glossary.

Tone and methodology

The site is a critical research project — not neutral, but source-faithful. Every claim has a Vancouver footnote. Independent systematic reviews weigh more heavily than publications from the original clinic. Full account at /methodology/. The position of Amsterdam UMC has its own, integrally reproduced page: /debate/response-vumc-amsterdam-umc/.

Contact

Stichting Genderinfo i.o. — editorial office. For substantive questions, background interviews or corrections: see /contact/. Response time for editorial enquiries: within 48 hours.