Can you buy retatrutide in the USA?

Not as an approved drug — Eli Lilly's own FAQ says retatrutide "has not been approved by any regulatory agency and is legally available only through Lilly's clinical trials," and that "anything sold to consumers outside of those trials is illegal, with no way to verify its safety, purity or dosing" (Lilly, "What to know about retatrutide," last updated July 2026). Since then Lilly has opened a limited early-access program (announced August 3, 2026) for adults 18 or older with treatment-resistant obesity and at least two serious obesity-related complications who cannot enroll in a trial, so trials are no longer Lilly's only route. That doesn't stop retatrutide from being sold anyway, labeled "for research use only," through the same market that sells tirzepatide, BPC-157 and others outside the pharmacy system. If that's the retatrutide you're actually asking about, the rest of this article is for you: what independent lab reports, mostly paid for by buyers, on 341 vials from that market show, and what to check before you trust any of them.

What the lab reports show

As of September 30, 2026, our database includes 341 retatrutide vials from 37 vendors, drawn from 193 lab reports dated October 2024 through September 2026 (on September 28, 2026, those reports came from 12 labs). On purity, 322 of the 341 tested vials (94%) came in at 99% or higher, with a median purity of 99.70%. 7 vials tested under 95% purity — and every one of those is also a fail under our definition (empty, under 95% pure, more than 20% under label, or more than 50% over), because purity is the cleanest, least ambiguous way a vial can go wrong.

Dose against label is where the spread actually shows up. Across 295 vials with both a label amount and a measured amount, the median result ran 8.2% over label. 94 of those (32%) landed within ±5% of label; on September 28, 2026, widening that to ±10% gave 167 of 292 (57%). At the tails: 6 vials measured more than 20% under label, and 30 measured more than 20% over. Altogether, 14 of the 341 tested vials (4.1%) failed; as of September 28, 2026, the failures were spread across 9 of the 37 vendors, with no more than 3 at any single one — 28 of the 37 vendors had no failed retatrutide vial on file at all.

Where overfill shows up most

Overfill isn't evenly spread across vial sizes. Among sizes with enough vials to say something as of September 28, 2026, 12 mg vials ran a median +19.8% over label and 15 mg vials +13.3%, both well above the compound's overall +8.2% median. Vials at 20 mg (+4.8%) and 60 mg (+2.5%) ran much closer to label, with 60 mg vials landing within ±5% most often of any size group. The 30 mg group — the largest single size in our data at 81 vials — had a +6.5% median but also accounted for 5 of the 6 vials measured more than 20% under label. None of this is a claim about why a given vial reads high or low; it's simply what the label-versus-measured numbers show once you sort by size, and it's worth checking the size on the report in front of you against these patterns rather than assuming the compound's overall median applies evenly.

By year, as of September 28, 2026, overfill was highest in 2025 (median +10.9% across 163 vials) and came down somewhat in 2026 (+5.7% across 159 vials), with a larger share landing within ±5% in 2026 (48 vials, versus 38 in 2025) — a trend worth knowing if you're comparing an older report against a newer one for the same vendor.

Endotoxin and sterility: what the tests found

As of September 28, 2026, sixty-one retatrutide results in our data include an endotoxin test — an add-on buyers order separately, not part of the standard purity/dose panel. Of those, 24 came back below the lab's detection limit and 1 was reported simply "pass." Among the 32 that gave a precise number: 12 were under 2 EU, 11 were 2–10 EU, 6 were 10–20 EU, 1 was 20–100 EU, and 2 were 100 EU or more, with the highest reported result at 1,438 EU/vial. A further 3 results were reported only as ">10 EU" and 1 as ">1000 EU/vial" — a threshold, not a precise figure. Units aren't consistent across reports (per-vial versus an unstated basis), so results aren't always directly comparable, and these are the vials buyers specifically chose to test for endotoxin, not a random sample of everything sold.

Sterility testing (measuring total aerobic microbial count and total yeast/mold count) is rarer still: just 7 retatrutide samples in our data as of September 28, 2026, and all 7 failed at least one of the two counts. That's a genuinely small sample, likely skewed toward vials someone already suspected might be a problem, and a failed microbial count on a sample prepared for lab testing is a lab finding about that sample — not a medical diagnosis about a person. It's still worth knowing the pattern exists in the data we have, which is why we report it rather than leave it out.

TFA and heavy metals, by contrast, came back clean where tested as of September 28, 2026: 5 TFA results, all "0" or "not detected," and 4 heavy metals results, also all not detected. Six LC-MS impurity screens described "retatrutide and degradation products," several noting mannitol, a common bulking agent in freeze-dried vials.

How vendors spread out

As of September 28, 2026, 9 of the 37 vendors with retatrutide results had enough reports (five or more) to be ranked on this compound. Here's the live picture, which updates as reports come in:

That table updates as new reports come in, so it's a better check than anything printed in an article, including this one. For the full, continuously updated breakdown by vial size and by year, see the retatrutide results page and our companion article, retatrutide test results: what 336 lab-tested vials show.

Test your own vial

A strong vendor pattern still describes other people's vials, not necessarily yours, and the data above shows real spread even among vendors with otherwise clean records. How to get a peptide tested covers ordering independent identity, purity and quantity testing, and when the endotoxin or sterility add-ons above are worth the extra cost; endotoxin in research peptides goes deeper on reading that specific result, including why the unit inconsistency described above matters when you're comparing your own report to someone else's.

Given the vial-size pattern above, it's worth ordering a quantity test specifically if you have a 12 mg or 15 mg vial, since those sizes have run furthest from label in our data so far; a 20 mg or 60 mg vial has historically landed closer to label, though that's a pattern across many vials, not a promise about any one of them. If a report comes back with a purity fail, a large underfill, or a sterility miss, the practical next step is the same regardless of vendor: stop using that batch, tell anyone else who bought from the same run, bring the report to the vendor, and submit it to VendorVerify so it's part of the public record for the next buyer checking that vendor.

Know the risks

To be direct about the legal side, briefly: retatrutide is investigational, not approved by any regulatory agency, and Lilly's FAQ (last updated July 2026) states that it was legally available only through its clinical trials, with anything sold outside them illegal. Lilly has since opened a limited early-access program (announced August 3, 2026) for eligible patients who cannot enroll in a trial. That's Lilly's product and Lilly's trial program, entirely separate from the research-labeled market this article is mostly about; the trials themselves are listed at ClinicalTrials.gov, run by the National Library of Medicine, if that route is what you're after instead. Everything discussed above concerning the research-labeled market is sold "for research use only," with none of the manufacturing oversight or release testing an approved drug gets before it reaches anyone — which is exactly why independent lab data, mostly paid for by buyers, is the only real check available, and why we track it.

Quotes above are from Eli Lilly's "What to know about retatrutide" FAQ, last updated July 2026. Database figures without a date update automatically from VendorVerify's lab results; dated figures are snapshots. All database figures describe only research-labeled products, entirely separate from Lilly's clinical trial program. This isn't medical or legal advice.