Best Retatrutide Brand UK 2026: Remedium vs Alluvi vs Synedica vs ProPeptide

ProPeptide Retatrutide — the highest verified triple-agonist pen purity

The ProPeptide-branded Retatrutide 20mg Pen carries the strongest single piece of evidence in this comparison: the finished-cartridge Janoshik report for batch RET-20-C-2604-001 — 99.841% HPLC, Task 150762, verify key APSLYZGYW4KA. That is the highest published retatrutide pen purity of the four brands, tested on the finished pen cartridge rather than raw material, and it is confirmable directly with Janoshik Analytical — the report is published in the COA library, so the route from carton to lab is public end to end.

ProPeptide is sold by Remy Peptides, the publisher of this page — and it holds the same top position in our Dubai supplier guide, weighed against 30+ suppliers in open market context. The test that puts it first here is the same one every brand below either passes or fails: not the number a seller quotes, but whether that number can be checked.

• Verified: Janoshik Task 150762 with a public verify key; batch-matched to the finished pen cartridge, not just raw material.
• Context: panels for endotoxin, residual TFA and heavy metals are published on the related vial-line batch (RET-20-V-2604-001), not on the 20mg pen batch — each report stays tied to its own batch.

Remedium Retatrutide Pen — the verifiable benchmark UK buyers actually meet

The Remedium retatrutide 30mg pen is Remy Peptides’ flagship research-use format: a prefilled FlexiPen with a 300-click dial mechanism, shipped cold-chain from Dubai. It ranks second on the raw purity number — its flagship batch tests at 99.262% against ProPeptide’s 99.841% — but not on proof quality: every published batch in the range resolves to a batch-specific Janoshik Analytical report you can confirm yourself, without trusting the seller. And because Remedium is the name UK resellers list — and counterfeiters copy — it is the brand where verification matters most.

• Verified: published retatrutide batches with Janoshik reports in the public COA library, batch numbers printed on cartons, verify keys where issued.
• Verified: official format range 10mg–40mg pens plus 10mg and 40mg vials; as of July 2026 the 30mg pen is the in-stock format, with the others listed reference-only until restocked.
• Caution: Remedium pens circulate in the UK through third-party resellers Remy Peptides does not operate — including listings for a “Remedium 50mg” pen, a format that has never existed. Verify any UK-bought pen’s batch number before trusting it (how to verify below).

Synedica Retatrutide — a real brand with nothing to check

Synedica is a real, currently active UK-market brand — commonly searched as “synedica retatrutide 40mg” — selling a retatrutide 40mg pen alongside a tirzepatide pen, through its own storefront and UK resellers. What we could not find is any evidence: as of 7 July 2026, its site publishes no certificate of analysis, no laboratory report and no purity claim of any kind — not even an unverifiable one. Product pages lean on customer star-reviews and describe the brand name as a “documentation reference” while disclaiming MHRA approval.

The press record is worse than the missing paperwork: Channel 4 News reported in October 2025 that it could not verify where Synedica is based, and that when its reporter contacted Eli Lilly — the developer of retatrutide (LY3437943) — the company confirmed the Synedica-branded product examined was a fake. Channel 4 said Eli Lilly was taking action against both Synedica and Alluvi. Synedica did not respond to the programme’s findings.

• Not verifiable: no COA, no named lab, no batch route — on the ranking rule, an unproven product regardless of what is actually inside.
• Sourced caution: named in Channel 4’s fake-retatrutide investigation (15 October 2025), with Eli Lilly reported as confirming an examined product fake.
• Why #3 and not #4: unlike Alluvi, Synedica has no regulator enforcement action on record. That is the entire gap — neither brand offers proof a researcher can check.

Alluvi Retatrutide — the brand in the MHRA raid coverage

Alluvi is the most-searched name on this page for the worst reason. In October 2025 the MHRA raided an illicit weight-loss-medicine production facility in Northampton and, per its 24 October announcement, seized “more than 2,000 unlicensed retatrutide and tirzepatide pens” branded Alluvi, along with tens of thousands of empty pens awaiting filling — describing it as the largest single seizure of trafficked weight-loss medicines recorded worldwide. The MHRA added that outside authorised clinical trials, any product sold in the UK claiming to contain retatrutide is likely to be illegal and potentially dangerous, and that a product sold online as retatrutide without regulatory approval may be counterfeit.

The Guardian then reported on 7 December 2025 that Alluvi-linked Telegram channels advertised being “still fully in stock via telegram” shortly after the raid became public, and that an Alluvi website remained up and selling retatrutide bundles as of early December. BBC reporting describes an Alluvi Telegram following in the tens of thousands and a test purchase that never arrived, underscoring the risks and possible adverse effects tied to unregulated supply. Alluvi’s own sites carry a self-claimed “≥99% purity” COA line — but name no laboratory and expose no batch, task or key a buyer could confirm. Channel 4’s October 2025 investigation named Alluvi alongside Synedica.

• Sourced caution: MHRA-announced seizure of Alluvi-branded pens (24 October 2025); continued post-raid sales reported by The Guardian (7 December 2025).
• Not verifiable: purity claim with no named lab and no confirmable batch route; BBC reported a test order that never arrived.
• Fairness note: every statement above is an attributed, dated citation of the MHRA, The Guardian, the BBC or Channel 4 News — the full trail is in the claims CSV.