Vendor Safety Methodology: How GLP3Planner Evaluates Peptide Sourcing

Editorial methodology · v1.0 · May 2026

GLP3Planner publishes pharmacokinetic tools and educational content for an audience that sources peptides outside conventional pharmacy channels. The vendor safety methodology documents how we evaluate that sourcing landscape. It is not a buyer's guide and not a ranking. It is the framework we apply before any vendor data appears anywhere on this site.

01Why this is methodology, not a "best of"

Most online vendor lists are commercial. Affiliate revenue picks the order, and the rubric is invisible. We took the opposite approach. The rubric is published. The dataset is dated. The rankings live in a separate, internal artifact that never leaves the editorial team without our review of the methodology that produced it.

Two reasons. First, the underlying market is structurally unstable. Seven or more major vendors closed in the 12 months before May 2026, including Peptide Sciences, which had been estimated at roughly 7.4 million dollars per month in revenue at its peak^[1]. A static "best of" page goes stale in weeks. Second, the readers we serve are evaluating vendors themselves. They benefit far more from understanding the rubric than from being handed a name.

This page is therefore a research instrument, not a recommendation. If a clinician, journalist, or regulator wants to understand how we read this market, the answer is below.

02The 2026 trust-signal stack

No single source can verify a research-chemical vendor end-to-end. Our methodology layers three independent signals, each of which addresses a different failure mode. None of them require trusting the vendor's own marketing.

Finnrick Analytics, the volume signal

Finnrick Analytics, a third-party peptide testing service, has analyzed roughly 6,937 samples across 205 vendors through the date of this writing^[6]. Vendors that submit samples voluntarily produce one kind of signal. Vendors that have never appeared in a Finnrick result produce another. We use Finnrick's per-vendor pages as a baseline for purity and identity claims.

Janoshik Analytical, the verification signal

Janoshik Analytical operates a public certificate-of-analysis verification portal at janoshik.com/verification^[7]. Any party can paste a COA reference and confirm whether the certificate was issued by Janoshik for the specified batch. Vendors that link out to Janoshik for batch-level COAs are verifiable in real time. Vendors that publish PDFs without a verifiable issuer are not.

Vanguard Labs, the parallel-supply signal

In March 2026, Vanguard Labs tested 11 bacteriostatic-water products sold on Amazon and found that 9 of 11 failed USP <797> sterility standards^[3]. That result reframes adjacent supplies, not just the peptide itself, as part of the safety surface. A vendor delivering a perfectly compounded vial does not protect a user who reconstitutes with non-sterile diluent. Our methodology now scores supplies as a separate dimension rather than treating them as commodity.

03The four-tier framework

Every active vendor in the dataset lands in one of four tiers based on how much of the rubric they satisfy. Tiers are descriptive, not prescriptive. They describe what the publicly verifiable evidence supports as of the most recent review window.

Three additional vendors that appeared in earlier survey rounds are tracked separately as shutdown: Peptide Sciences (closed March 2026), Amino Asylum (FDA-raided June 2025), and Paradigm Peptides (founders pleaded guilty to federal charges December 2025)^[1][2]. They appear nowhere in the active framework but are retained in the dataset as historical reference points.

04The six-criterion rubric

Every vendor is scored 0 to 5 on each of six dimensions. Each score is paired with a plain-text evidence note and at least one source URL captured on the date of review. Scores without sources do not count.

Two additional flags sit alongside the rubric without being scored: a binary licensed / gray-market tag based on whether the vendor operates as a licensed telehealth or pharmacy entity, and a review window date that triggers re-verification on a 90-day cadence. Of the 40 active vendors, 22 carry the licensed tag and 23 carry the gray-market flag (overlap exists where a licensed parent operates a separate research-only line).

05What changed in 2025 and 2026

A safety methodology written in 2024 would have looked different. Three industry-level shifts forced a structural rewrite in early 2026.

Compounding pharmacy enforcement

On March 9, 2026, Hims & Hers announced a strategic shift away from compounded GLP-1 marketing in the United States, following a settlement with Novo Nordisk^[4]. The withdrawal of one of the largest direct-to-consumer compounded providers redistributed customers across smaller vendors with thinner operational track records, several of which are in the T-3 tier.

Vendor mortality

Peptide Sciences, the largest US peptide research-chemical vendor at its peak, shut down on March 6, 2026^[1]. Amino Asylum was raided by the FDA in June 2025 after repeated warning letters. Paradigm Peptides founders pleaded guilty to federal charges in December 2025. Three large exits in nine months changed the assumed baseline that "the vendor that exists today will exist next quarter."

Border and supply

US Customs and Border Protection seized more than 5,000 China-direct peptide shipments between December 2025 and March 2026^[5]. The seizure pattern shifted apparent risk away from US-warehoused vendors and toward direct-import channels. Our methodology now weights US warehousing in the shipping-integrity criterion.

Adjacent-supply quality

The Vanguard Labs analysis of Amazon BAC water in March 2026 (9 failures out of 11 samples) means the diluent is no longer a commodity step in the safety chain^[3]. Methodology v1.0 treats syringes, BAC water, and vials as scored alongside the peptide itself.

06What this methodology cannot do

Stating limits is part of methodology, not a footnote to it.

• It cannot certify a specific shipment. A third-party COA verifies a specific batch tested at a specific lab. The vial in a buyer's hand may or may not be from that batch.
• It cannot diagnose, dose, or treat. Tier and rubric data describe a vendor's transparency, not the medical appropriateness of a given compound for a given person. Clinical decisions belong with a clinician.
• It is point-in-time. The 90-day re-verification cadence is the maximum acceptable staleness. Anything older has not been re-checked.
• It does not score by community sentiment alone. Forum threads inform the research, but mention counts on r/Peptides or CompoundTalk are weighted as community signal, not evidence of vendor quality. Curated and inauthentic-review patterns are tracked as separate flags.

07Press-ready summary

The block below is the version of this methodology designed to be quoted directly. Every figure is sourced in the references list. Use of these figures is not gated by anything; attribution to GLP3Planner is appreciated.

08Tools that support this work

Vendor evaluation is upstream of the practical questions readers usually arrive with. Two free tools on the site sit downstream of it.

The GLP3Planner pharmacokinetic calculator models drug levels over time using clinical-trial parameters. It does not depend on vendor choice. The reconstitution calculator handles BAC-water mixing math for common vial sizes. Methodology for the PK model is documented separately at PK Methodology.

The full vendor research dataset is not publicly published as a page. Editorial, journalistic, and research access is available on request through [email protected]. Requests that include the publication, the angle, and the deadline get prioritized.

09Methodology change log

10References