NES/T Transdermal Gel
Nestorone (Segesterone Acetate) + Testosterone Gel - the Current Lead Candidate
Evidence grade 3 of 5, Mixed. Read how the Atlas grades evidence.
The written rationale for this grade is still being prepared.
- FDA
- Investigational; in Phase 2b efficacy trial (NICHD / Population Council). Not FDA-approved (2026)
Reference only. Not medical advice.
What can go wrong
As an androgen-progestin gel, reported effects include acne, weight change, mood changes, libido shifts, and altered lipids/HDL; transdermal products carry a skin-transfer caution. Reversibility is expected but, as with all hormonal candidates, recovery of fertile sperm counts takes months. Long-term safety data are still being generated through the ongoing trial.
This is something to take to a clinician. The Atlas can tell you what is known about nes/t transdermal gel in general. It cannot tell you what is happening in your body, and the difference matters most for exactly the symptoms that bring people to this page.
NES/T is a daily transdermal gel combining Nestorone (segesterone acetate), a potent non-androgenic, non-estrogenic progestin, with testosterone. Applied to the shoulders/upper arms each day, the progestin drives gonadotropin (and thus spermatogenesis) suppression while the testosterone maintains serum androgen levels. It is the furthest-advanced reversible candidate, run by the NIH's NICHD with the Population Council, in a multinational Phase 2b contraceptive efficacy trial. Earlier studies reported that a large majority of men reached the suppression threshold, generally within several months.
A gel you rub on your shoulders each morning - and the closest thing to a male pill we have.
What people take it for
These are the reasons people give for taking it. They are not effects it has been shown to have.
How it is supposed to work
Nestorone is a 19-nor progestin with strong progestational activity but minimal androgenic, estrogenic, or glucocorticoid effects, so it suppresses LH/FSH efficiently without adding its own androgenic burden. The co-formulated testosterone replaces the suppressed endogenous androgen to keep serum testosterone physiological. Together, transdermal daily dosing collapses intratesticular testosterone and halts spermatogenesis, with the gel format avoiding injections and allowing rapid washout if discontinued.
Why the gel format matters
A daily gel is more easily stopped than an 8-weekly depot injection, addressing reversibility concerns: if a man stops applying it, hormone levels fall and the axis can recover. The tradeoff is adherence - daily application and a skin-transfer caution (avoiding contact transfer to partners/children) - versus the convenience and forgiveness of a long-acting injectable. NES/T's progestin-driven design also aims to suppress more men than testosterone-only regimens.
What it does to fertility
Designed for reversible contraception via suppressed spermatogenesis. Earlier-phase data and the trial design assume return to fertile sperm concentrations after discontinuation; confirming the reversibility timeline is part of the program.
What has to be monitored
The bloodwork this needs, and the reason it belongs with a clinician rather than a website.
- Serum testosterone
- Semen analysis (suppression and recovery)
- Lipid panel (HDL)
- Mood, weight, acne, skin-transfer counseling
What people get wrong
Often saidNES/T is approved and you can ask a doctor for it
ActuallyIt is investigational and only available within the clinical trial; it is not FDA-approved or prescribable as of 2026.
Often saidA gel can't suppress sperm as well as an injection
ActuallyCombination Nestorone/testosterone gel studies reported a large majority of men reaching the suppression threshold, comparable in goal to injectable regimens.
Who profits, and who pushes back
Nobody is named here yet, because we have not done that work on this entry. Read that as unfinished. Somebody almost certainly sells this, and somebody almost certainly disputes it. Assume both until we have checked.
At a glance
- Components
- Nestorone (segesterone acetate) progestin + testosterone
- Route
- Daily transdermal gel to shoulders/upper arms
- Sponsors
- NICHD (NIH) and the Population Council
- Stage (2026)
- Phase 2b multinational contraceptive efficacy trial (ongoing)
What this entry does not yet cover
What follows is unfinished work on our side, not a finding about NES/T Transdermal Gel. A short entry is not a safe entry.
- Timeline. We have not built the dated record of research and regulatory events.
- Cost and market. We have not documented what it sells for or who sells it.
- Supply chain. We have not mapped where it is made.
- Who uses it. We have not documented the user groups.
- What could change. No forward-looking summary yet.
- How it compares. We have not set it against the alternatives.
- Children and teenagers. We have not checked what is known about younger people.
- Where we land. We have not taken a position on this yet.
Sources
The studies below are named and described, but not linked. You cannot open them from here and check our reading against them, which means this page is our summary of the literature rather than a document you can verify. Weigh it accordingly until the links exist.
The studies that matter
Ilani et al., JCEM - Nestorone/testosterone gel suppression study2012
Combined Nestorone + testosterone gel suppressed sperm output more effectively than testosterone gel alone, supporting the combination
NICHD/Population Council NES/T Phase 2b efficacy trial2018-2026 (ongoing)
Large multinational trial evaluating daily NES/T gel for contraceptive efficacy and reversibility - the lead reversible candidate