Reproductive & sexual health
Nafarelin
A GnRH agonist that has been an approved nasal-spray medicine for decades — the standing rebuttal to 'nasal peptide means research chemical'.
- How settled this rating is:
- high confidence in the current evidence rating
- Routes studied:
- Nasal
- Also known as:
- Synarel, nafarelin acetate
- Last reviewed:
- 2026-08-23
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Evidence passport
Nafarelin
A one-screen evidence identity for this compound. These fields describe research maturity, confidence and legal status. They are not a safety guarantee, efficacy percentage or recommendation.
- Evidence level
- L5Repeated human trials
- Confidence
- High confidence in rating
- Regulatory status
- Approved for a specific indication · See jurisdiction details
- Development status
- Approved
Evidence strength
Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.
Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number.
The 0-100 values rate the strength and maturity of evidence, not how effective or safe the compound is.
- Evidence base
- Includes human studies
- Furthest established stage
- Approved
- Human research maturity
- Long-approved medicine with extensive clinical history
- Source curation
- Sources fully curated
Routes recorded
Overview
Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.
Higher = more animal, tissue or cell research. Preclinical results are a starting point, not proof of a human benefit.
Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number.
How to read these scores
Every number here rates the evidence, not the compound. They are editorial 0-100 strength ratings, not percentages, and not a rating out of five stars.
- Human efficacy evidence strength — Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.
- Preclinical evidence strength — Higher = more animal, tissue or cell research. Preclinical results are a starting point, not proof of a human benefit.
- Human safety evidence strength — Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number. A score of 80 does not mean “80% safe”.
- Evidence level (L0-L5) — the strongest type of study behind the compound, from anecdote (L0) to large replicated human trials (L5). It is a description of the study evidence, not a quality, safety or recommendation rating.
- Confidence — how likely we think it is that this rating changes as new research lands. Low confidence means the picture is unsettled, not that the compound is bad.
None of these ratings is medical advice, a safety guarantee, or a recommendation to use anything. How we grade evidence.
How far human research has progressed: Long-approved medicine with extensive clinical history
Routes & formulations
Studied / approved routes
The approved product is a metered nasal spray — a demonstration that intranasal delivery is a legitimate regulated route for some peptides, not a marker of the grey market.
Route availability is not evidence of efficacy, and evidence from one route does not transfer to another. The Registry never provides dosing or sourcing information.
Peptide lifecycle
Discovery
Preclinical
Phase I
Phase II
Phase III
Approved
What it is
A synthetic GnRH agonist that, with continuous use, down-regulates the pituitary-gonadal axis rather than stimulating it.
What people claim
- Manages central precocious puberty
- Historical use in endometriosis depending on market
What the evidence actually says
Decades of regulated clinical use support its labelled indications. It is a useful calibration point in this registry: the same molecule class that appears in research-market catalogues also contains serious, long-established medicines.
Related evidence
Useful next reads based on this compound — not recommendations.
- Related compound
Triptorelin evidence profile
A long-acting GnRH agonist depot used in prostate cancer and central precocious puberty.
- Compare
Compare Nafarelin vs Triptorelin evidence
Same questions, same fields, side by side — including how much human evidence exists.
- Context
Safety Centre
What approved, investigational and unapproved actually mean for documented human safety.
- Context
Research Desk
How to read animal, early-phase and controlled human studies without over-reading them.
Human evidence
- Controlled trials supporting approval and long post-marketing experience.
Preclinical evidence
- GnRH receptor pharmacology and reproductive endocrinology studies.
Animal and cell findings are Level 1–2 evidence.
Mechanism and pathways
- Continuous GnRH-receptor agonism desensitises the pituitary, suppressing LH/FSH and gonadal steroids.
Safety and unknowns
- Effects are dominated by the intended hormone suppression (e.g. hypoestrogenic symptoms).
- Long-labelled medicine with defined contraindications and monitoring.
Cancer relevance
This section covers questions raised by how the compound works in the body, plus anything regulators and trial teams keep an eye on. It is not a statement that this compound causes cancer — for most compounds here, no human data exist in either direction.
No concern identified
Regulatory status
Regulatory decisions apply to specific jurisdictions, products, formulations and indications. An approval elsewhere is not automatically an approval in your country.
Named regulators: FDA (US)
FDA-approved nasal solution (Synarel) for central precocious puberty; endometriosis labelling has varied by market and label revision. Approval is indication-specific.
Evidence grade
Substantial, consistent controlled human evidence supporting a specified outcome, preferably independently replicated. Approval is reported separately.
What would change our rating?
- Not applicable at this evidence tier; routine pharmacovigilance continues.
References and sources
Source transparency
A provenance snapshot of this profile. Counts show what kinds of sources are cited, not how much scientific weight each source deserves.
- Last editorial review
- 2026-08-23
- Recently reviewed · 54 days ago
- Linked curated sources
- 2
- Sources still pending
- 0
- External specialist reviews
- 0
- None recorded for this profile
Review provenance
Registry editorial review: Colin Jackson-White, creator and editor, who is not a doctor or clinician. External specialist review is credited only when a named reviewer has completed a review of this exact profile.
Literature-discovery and AI tools may help locate or challenge candidate evidence, but they are not counted as evidence sources here. Registry judgements are tied to the underlying papers, trial records, regulator documents and official study records.
- Regulatory / labelFDA orphan drug record — nafarelin
- Regulatory / labelFDA label — Synarel (nafarelin acetate) nasal solution
Source hierarchy: regulatory documents and trial registries first, peer-reviewed work next, sponsor material flagged as non-independent. We never use supplier or clinic marketing as evidence, and where a verified source has not yet been curated we say so rather than inventing one.
Evidence change history
These entries record changes to our assessment of the published evidence — not changes to the compound itself.
No recorded changes yet. Baseline position set on 2026-08-23.