Retatrutide price UK: what a vial costs, vendor by vendor
Every UK vendor we could verify, the retatrutide cost per vial and per milligram at each size, how each one tests, and where the stock sits. Checked 18 September 2026; updated monthly.
| Vendor | 10 mg | 20 mg | 30 mg | 40 mg | Testing | Stock and dispatch |
|---|---|---|---|---|---|---|
| ALTA PEPTIDES (this site) | – | – | – | £139.99£3.50/mg | Manufacturer certificate for lot 07022601 published; same lot independently tested by Janoshik (99.752%, via the pen) | UK stock, same-day before 1pm |
| ALTA PEPTIDES Retatrutide Pen (this site) | – | – | – | £159.99pen† £4.00/mg | Retatrutide from lot 07022601; manufacturer certificate and ALTA's independent Janoshik test (report 240684, 99.752%) published | UK stock, same-day before 1pm |
| Astra Labs | – | – | – | £139.99£3.50/mg | Janoshik Analytical, COA on request | UK, dispatch 24 to 48 h |
| Peptides UK 4U | £49.99£5.00/mg | £89.00£4.45/mg | £119.00£3.97/mg | £154.00£3.85/mg | European lab, batch COA published | UK stock, same-day before 1pm |
| Peptide Products | – | – | – | pen £125.00* | Not stated on listing | UK |
| UK Peptide Lab | – | – | – | – | n/a | Discontinued |
* A pen listed by another vendor is a solution the vendor has prepared and loaded into a drug-delivery device itself, not a research vial, and its price includes that preparation; it is shown for completeness only. † Our Retatrutide Pen is a sealed Synedica pre-filled 40 mg pen with needles, filled by the manufacturer and supplied as received, with the certificate for the loaded retatrutide (lot 07022601) published; it is priced per pen, so the per-mg figure includes the device. Vendors that have withdrawn the product are listed so the picture is complete.
How much does retatrutide cost in the UK?
On 18 September 2026 the retatrutide price for a 40 mg research vial from a UK vendor ran from £139.99 to £154.00, which is £3.50 to £3.85 per milligram. Smaller vials cost more per milligram everywhere they are sold: a 10 mg vial at £49.99 is £5.00 per mg, a 20 mg vial at £89 is £4.45 per mg, and the 40 mg size is the cheapest way to buy the compound at every vendor that offers it. That is why our own listing is 40 mg only.
The retatrutide cost quoted by a vendor is only half the comparison. The other half is what you get for it: whether the lot has been tested by a named laboratory, whether the certificate is published or only "on request", whether the vial physically ships from the UK, and whether the vendor is a registered company. A cheap vial with no certificate is not cheap. Our guide to reading a certificate of analysis explains what to look for, and our UK buying checklist covers the rest.
Why the retatrutide price is falling
Twelve months ago a 40 mg vial in the UK was typically £180 to £220. Manufacturing capacity has caught up with demand, several vendors now compete on the 40 mg size specifically, and the compound's move into phase 3 has made it a commodity research reagent rather than a rarity. At the same time at least one established vendor, UK Peptide Lab, has withdrawn it altogether, which reflects the regulatory pressure on the GLP-1 class rather than any change in demand. Expect the retatrutide UK price to keep drifting down while supply holds, and expect the vendor list to keep changing.
Vials, pens and what "price per month" means
Some vendors quote a retatrutide price per month or per dose. That is human-use language: it assumes the compound is being administered to a person on a schedule, which no vendor can lawfully supply it for, and it makes the price impossible to compare. The only honest unit for a research reagent is price per milligram of tested material, which is what the table shows. Pens are priced separately above because they are a different product from a vial: the compound already in solution in an injector device, with the preparation and the device included in the price. Where another vendor has reconstituted a vial and loaded the pen itself, there is no manufacturer or certificate behind what is in the cartridge. Our own Retatrutide Pen, marked †, is a sealed Synedica pre-filled 40 mg pen with needles, filled by the manufacturer and supplied as received, and the retatrutide in it is from the same published lot as our vial. Per milligram it costs more than our 40 mg vial because the price includes the device, which is why the vial remains the cheapest way to buy the compound from us. Our pen versus vial article sets out the formats.
How this page is compiled
We check each vendor's public product page, record the vial price displayed for each size including VAT, and note the testing and dispatch claims as stated. We do not adjust for discount codes, bundles or delivery. The list includes vendors that appear in UK search results for retatrutide; it is not exhaustive and we add vendors as we find them. Prices were last checked on 18 September 2026 and the page is rebuilt monthly. If you find a UK vendor listing we have missed, or a price that has changed, tell us and we will update it.
Retatrutide is an investigational medicine with no marketing authorisation anywhere. Every vial in the table is sold, by every vendor, as a research reagent for laboratory use only. Nothing on this page is a recommendation for any other use; see our research use policy and our explainer on UK law.
Between £139.99 and £154.00 for a 40 mg research vial as of 18 September 2026, or £3.50 to £3.85 per milligram. Smaller vials cost more per milligram.
40 mg, at every vendor that sells it. Per-milligram cost falls as the vial gets larger.
A pen is the compound already in solution in an injector device, so its price includes the device and the preparation; a pen another vendor has filled itself is a different product from a vial and carries no certificate for what is in the cartridge. Our own Retatrutide Pen is a sealed Synedica pre-filled pen from a named manufacturer with the lot certificate for the loaded retatrutide published, priced per pen, and costs more per milligram than the 40 mg vial because the device is included.
Only if the lot is tested by a named laboratory with a published certificate and ships from UK stock. Compare on those points as well as price.
Monthly. The date of the last check is shown at the top of the page.