Every number, approval date, and trial reference on this site is traced to a cited primary source. This page explains how we choose sources, handle conflicting evidence, and keep the data current.
If a claim cannot be verified against an authoritative source, it does not appear on NonHormonal.com. We would rather show a missing field than an unverified number. When a data point is unknown or contested, we say so explicitly in the relevant details field rather than filling the gap with a guess.
This applies to every data type we publish: efficacy percentages, FDA approval dates, clinical trial IDs, manufacturer names, and cost ranges.
We use a fixed source hierarchy so the same kind of claim is always traced to the same kind of authority. When a newer authoritative source supersedes the one listed here, we update the hierarchy first, then update the affected pages.
Every cited source URL must be freely accessible, with no paywall or login wall, so readers can verify anything we cite. We prefer PubMed over journal pages because PubMed is always free and contains the abstract with the headline numbers, and we avoid rate-limited or paywalled sources in favor of freely accessible equivalents.
Primary sources often report annual failure rates (for example, 13% typical failure for external condoms). We mathematically invert these to a consistent "effectiveness rate" format for consumer scannability (87% effective), while preserving the original measurement context in the details field so the inversion is traceable.
Every efficacy entry has either a numeric value, an efficacy tier (which we call a bucket), or both. The bucket gives readers an immediate "does this work?" signal without requiring a single percentage that may not exist.
Contraception tiers follow the CDC classification. The CDC groups contraceptive methods into three tiers by typical-use failure rate: Tier 1 (at least 99% effective, labeled "Most effective"), Tier 2 (90 to 99% effective, labeled "Moderately effective"), and Tier 3 (under 90% effective, labeled "Least effective"). These boundaries are authoritative and we do not adjust them. When a product has its own typical-use number, the tier is derived automatically. When it does not, the product inherits the tier of its method class, with the Guttmacher URL cited as the source.
Menopause tiers follow NAMS recommendation status. The Menopause Society 2023 Nonhormone Therapy Position Statement assigns each treatment a recommendation level: Level I ("Recommended"), Levels I-II or II-III ("Recommended, limited evidence"), or Not Recommended. For genitourinary syndrome treatments, the NAMS 2020 GSM Position Statement is used instead. The bucket is independent of the numeric efficacy value: a treatment can be "Recommended" with a modest percentage, or "Recommended" with no percentage at all.
"Limited evidence" is honest, not a judgment of failure. It means we cannot verify efficacy for a specific product. It does not mean the product does not work. "In trials" is used for investigational treatments that are still in preclinical or early clinical stages with no published human efficacy data.
Every clinical trial listed on a product or method page includes the trial name, phase, recruitment status, registry ID, and a direct URL to the registry record. Registry IDs are checked to confirm they resolve before they are added. Trial status is checked against ClinicalTrials.gov and updated when it changes. Trial URLs always link directly to the specific study record, not the registry homepage.
For approved products, side effects and contraindications are verified against the Contraindications and Adverse Reactions sections of the FDA label on DailyMed. For class-level methods, they are verified against CDC U.S. MEC or NAMS guidelines. We do not list speculative or unsourced safety details.
Cost figures are estimates, not guarantees. They go stale as prices change, so we review them quarterly and always include context about what each figure represents: list price, cash price, with-savings-card, insurance copay, App Store price, and so on.
Every cost entry has two labels that together tell you exactly what you are looking at. The first describes how often the product is consumed or repurchased: per act (condoms, spermicide), per month (a daily pill), per year (an app subscription), weekly (Saheli), or one time (a device or procedure). The second describes what the price number itself covers: a single unit (one condom), a retail package (a can of foam, a box of applicators), one billing period (a month's supply), or the total cost (a device, a procedure). A spermicide used per act but sold in a multi-dose can is labeled "per act / per package" so the price is not mistaken for a single dose.
When two authoritative sources report different numbers for the same claim, we prefer the higher-quality evidence type (randomized controlled trial over cohort, cohort over survey, survey over expert opinion) and the source closer to the data (the FDA label over a secondary summary, the primary trial publication over a review). If quality is equal, the more recent source wins.
Commercial relationships do not influence the data. Affiliate links, provider partnerships, and sponsorships never shape efficacy numbers, efficacy tiers, approval dates, side effect listings, or editorial prose. The commercial call-to-action link on a product page is added only after the clinical content is finalized, and it is the only commercial surface on that page. Payments from partners, including commissions and referral fees, have no influence on which methods or products we list, how we describe them, or the numbers we publish. The methodology described here is applied the same way regardless of whether a product has an affiliate link or not.
Each content file carries two dates that track its lifecycle. The "Last verified" date is when the data was last checked against its primary sources: efficacy numbers traced to the cited trial, FDA approval dates confirmed against DailyMed, trial statuses confirmed against ClinicalTrials.gov, and manufacturer names confirmed against the current label. The "Updated" date is when the content was last edited. "Last verified" is the primary trust signal and appears alongside the schema.org MedicalWebPage metadata that search engines use to assess content freshness.
The fixed source hierarchy itself is formally audited every 12 months. This ensures the foundational guidelines — the CDC U.S. MEC and SPR, The Menopause Society position statements, WHO fact sheets, and others — are systematically checked against the latest national or international consensus updates. When a newer edition supersedes a canonical source, we update the hierarchy first, then update every page that cites the superseded source.