Clinical Cases in Pharmacology Clinical Cases  ·  Endocrinology, Diabetes and Metabolism IV  ·  Male Reproduction  ·  A Shot That Isn't on the Market Yet
Endocrinology, Diabetes and Metabolism IV, Case EndoMaleRepro-0016 — Male Reproduction

A Shot That Isn't on the Market Yet

A 36-year-old asking for a male birth control shot he saw discussed online, in a field where the most promising candidate has completed only Phase 2 and nothing is actually FDA-approved yet.

Abbreviations, terms, and other agents mentioned in this case NES/T — Nestorone/testosterone transdermal gel, an investigational male contraceptive  ·  RAR-alpha — retinoic acid receptor alpha  ·  FSH — follicle-stimulating hormone
Presentation

Preston H. and his wife have two children and have relied on her hormonal contraception for the past nine years, a decision she raised wanting to revisit after a difficult year of side effects that finally prompted the conversation Preston is having today. He is not interested in a vasectomy, describing real ambivalence about a procedure he perceives as more permanent than he wants to commit to right now, even knowing reversal is sometimes possible. He mentioned, somewhat tentatively, having seen discussion online of a male birth control shot or gel, and a passing reference to a friend of a friend who he believes obtained something similar through an online source outside a formal medical setting.

What Preston is describing, once the conversation moves past the vague online references, is almost certainly a version of the same unregulated hormonal-suppression pattern discussed with a different patient, and a different goal, elsewhere in this volume: no FDA-approved male hormonal contraceptive currently exists on the market, in the United States or anywhere else. The furthest-along real candidate is NES/T, a combination transdermal gel containing Nestorone and testosterone that suppresses spermatogenesis through the same LH- and FSH-suppressing mechanism at issue in several fertility-related cases in this volume, deliberately turned toward contraception rather than treated as an unwanted side effect. A large Phase 2 trial presented in 2024 found that 86% of the 222 enrolled men achieved adequate sperm suppression by fifteen weeks of daily application, at a median of under eight weeks, a genuinely promising result. Its contraceptive-efficacy phase, in which couples relied on the gel alone, has since completed in 462 couples, but a Phase 3 program is still only in planning rather than underway.

A second, non-hormonal candidate, YCT-529, works through an entirely different mechanism, blocking a vitamin A receptor in the testes required for normal sperm maturation without altering testosterone, LH, or FSH at all — an approach that, if it succeeds through further trials, would avoid the mood, libido, and metabolic side effects hormonal methods can carry. It remains in early-stage Phase 1b/2a human trials as of this year, evaluating safety and tolerability over repeated dosing periods, with no efficacy data yet established. Neither product is available for prescription or purchase outside these formal trial protocols, and anything obtained through an unregulated online source claiming similar effects carries the same unverified dosing and purity concerns, and the same absence of any confirmed contraceptive reliability, as the compounded hormone products discussed elsewhere in this volume — with the added, specific consequence here that a false sense of contraceptive security carries real stakes for an unplanned pregnancy, not only for Preston's own health.

Preston H. · 36 Contraceptive Counseling
History
Married, 2 children, wife discontinuing hormonal contraception after adverse effects
Stated preference
Wants to avoid vasectomy; interested in a hormonal male contraceptive option
Exposure described
Vague reference to an online source outside formal medical care
Current contraception
None reliable currently in place while this is discussed
Testosterone / fertility labs
Not yet indicated; no diagnosis being evaluated here

Counseling visit, separating real research from an unverified shortcut

Andrologist Opening

I want to be direct with him before anything else: no FDA-approved male hormonal contraceptive exists anywhere right now, in the U.S. or elsewhere. Whatever he's describing obtaining through an online source outside formal care is almost certainly the same unregulated-hormone pattern we've seen carry real, documented risk elsewhere — unverified dosing, no monitoring, and here, on top of that, no confirmed contraceptive reliability at all. A false sense of security on that front has real consequences beyond his own health.

Primary Care Physician Response

I agree with every word of that warning, and I don't want it softened. What I don't want to happen is for him to leave here with only a no. He and his wife have a real, legitimate reason to be having this conversation, and if there's an actual trial site enrolling nearby, that's a genuine, monitored way to be part of exactly the research he's curious about, rather than an unregulated approximation of it.

Turning him away with a warning and nothing else is how men end up going back to the source we're warning him about.

Clinical Pharmacologist Final

Then let's give him the real picture. NES/T, the furthest-along candidate, showed 86% of men reaching adequate sperm suppression by fifteen weeks, median under eight, in the Phase 2b trial presented at ENDO 2024; its contraceptive-efficacy portion has since completed in 462 couples, and Phase 3 is in planning but has not started. YCT-529, a non-hormonal option, is still in early Phase 1b/2a safety testing with no efficacy data yet. Neither is available outside those trials. I'd check whether an active site is enrolling near him, and in the meantime recommend a reliable existing method — condoms, or revisiting vasectomy once his stated ambivalence has had a real conversation behind it, not simply as a fallback.

Regimen selected
Clinical Trial Referral (NES/T or YCT-529, if enrolling)
Referral · Investigational, monitored
Connects Preston with the actual, supervised research he's interested in, if a site is geographically accessible, rather than an unregulated approximation of it.
Condoms, Interim Reliable Method
Non-hormonal · Immediate
A reliable, immediately available option while longer-term decisions about vasectomy or trial enrollment are made, ensuring he isn't left without contraception in the meantime.
Unregulated Compounded Hormonal Suppression — Ruled Out
Not offered or endorsed
Carries the same unverified dosing and monitoring risks as compounded testosterone products discussed elsewhere in this volume, with no confirmed contraceptive reliability behind it at all.
Vasectomy — Discussed, Not Decided Today
Procedure · Revisit at follow-up
Remains a reliable, available option; deferred today specifically to give his stated ambivalence about permanence a fuller conversation rather than defaulting to it as the only real alternative.
Where this was left

Agreed: a search for active NES/T or YCT-529 trial enrollment near Preston, condoms recommended as a reliable interim method, and a follow-up visit scheduled specifically to continue the vasectomy conversation once his stated ambivalence has been discussed more fully rather than resolved in a single visit.

The andrologist's caution about the unregulated source Preston described was not softened by the group's effort to also give him a real path forward — both were delivered together, in the same visit, rather than the warning being traded off against the offer of help.

Educational content only — a composite teaching case, not a real patient encounter or a substitute for clinical guidance. About These Cases →