Buserelin
Aliases: Suprefact · Suprecur
Last verified: 2026-09-23
The short version
A GnRH agonist — prostate cancer, endometriosis, IVF protocols; available nasally and injectable.
Identity & type
- Molecular type
- analog
- Origin
- A GnRH agonist — prostate cancer, endometriosis, IVF protocols; available nasally and injectable.
Mechanism of action
GnRHR agonism → desensitization.
Dosing & routes
Official / clinical context
Approved drug — indications, dosing and warnings are defined by the official label. Nasal 300–400 mcg 3×/day; depot IM monthly.
Regulator-approved labeling and published study designs — never a recommendation.
Community-reported practice
Nasal 300–400 mcg 3×/day; depot IM monthly. Depot/nasal GnRH agonist: effective hormonal suppression in prostate cancer/endometriosis; patients report flashes and mood changes.
Unverified self-reports. Not medical advice. Not endorsement.
Expected effects (community)
Depot/nasal GnRH agonist: effective hormonal suppression in prostate cancer/endometriosis; patients report flashes and mood changes.
Protocol — official vs community
Official / label
Suprefact (prostate cancer): depot 3.75 mg SC every 4 weeks (or 11.25 mg every 12 weeks) after an initial phase of daily short-acting dosing to blunt the flare. IVF short protocols: 300–600 mcg SC daily. Nasal 300–400 mcg 3×/day is an older, adherence-dependent option.
- 01Prostate cancer: begin with daily SC short-acting doses (or co-administer an antiandrogen) before the first depot to cover the LH/testosterone flare
Duration: Prostate cancer: continuous, years. IVF: days per stimulation cycle.
The agonist flare is pharmacologically real — testosterone rises before pituitary desensitization, and in metastatic prostate cancer that flare must be covered.
Community (anecdotal)
Same niche as nafarelin: GnRH agonist suppression appears in PCT and fertility-recovery circles, using nasal or SC daily dosing (300–600 mcg SC/day) rather than depot.
- Cycle:
- Weeks to a few months, usually as one component of a multi-drug recovery stack.
- Break:
- Reversible on stopping; community logic treats suppression duration as a trade-off against symptom burden.
Choosing an agonist over an antagonist in an unsupervised setting buys a flare period that needs managing — the community literature on this is thin, which is itself telling.
Human evidence
Long clinical use.
Preclinical evidence
The preclinical phase was completed and submitted to regulators as part of registration; pharmacology and toxicology details are part of the official label.
Known risks
- Hypogonadal symptoms with long use.characterized
Teal: characterized in clinical/labeling contexts. Amber: theoretical or reported outside controlled settings.
Unknowns & evidence gaps
- Real-world data outside controlled trials