Frequently asked questions

Research peptides are short chains of amino acids synthesised for use in laboratory research, studying receptor signalling, tissue models, metabolism and more. They are chemical reference materials, not medicines: nothing sold on this site is approved for human or veterinary use, and everything is supplied strictly for in-vitro research by qualified researchers.

Retatrutide (LY3437943) is Eli Lilly's investigational "triple agonist" peptide, a single molecule that activates the GIP, GLP-1 and glucagon receptors simultaneously. Phase 2 results published in the New England Journal of Medicine reported the largest weight reductions seen in an obesity trial to date, which has made it the most studied metabolic research compound of the moment. It remains investigational: it is in phase 3 trials and holds no MHRA or FDA marketing authorisation, so it is available in the UK only as a research compound or within regulated clinical trials.

They differ in how many incretin-axis receptors they activate. Semaglutide is a selective GLP-1 receptor agonist, the reference compound of the field. Tirzepatide is a dual agonist, adding GIP receptor activity. Retatrutide is a triple agonist, adding glucagon receptor activity on top of GIP and GLP-1. In published clinical research, each added receptor pathway has been associated with progressively greater metabolic effects. All three are supplied here for laboratory research into these pathways only.

Because these compounds are not licensed medicines. Selling them for human consumption would be unlawful; supplying them as chemical reference materials for laboratory research is not. This is why we never provide dosage guidance or human-use instructions, why our labels state "not for human consumption", and why you confirm researcher status at checkout. It protects you, and it protects us.

Every compound is synthesised to a ≥99% purity specification and supplied as lyophilized powder in a sealed glass vial. The specification for each compound is listed on its product page.

Yes, where the manufacturer supplied one for the batch we hold. It is shown on the product page for that size, and every one is listed on our Quality page, with the supplier's details blurred. The full certificate is available on request: send us a message naming the product and size.

Lyophilized (freeze-dried) peptides are best stored at -20°C, protected from light and moisture; short-term storage at 4°C is acceptable for most compounds. Lyophilized powder is stable at ambient temperature for typical transit periods, which is how vials ship. Storage guidance is printed on each vial and listed on every product page.

Orders placed and paid before 2pm on a business day (Monday to Friday, excluding UK public holidays) are dispatched the same day via Royal Mail Tracked 24 in discreet, protective packaging, and arrive usually the next working day after dispatch. Standard shipping is £4.99, free on orders over £80, and orders over £120 arrive with a free research vial. We ship within the United Kingdom only.

A vial you did not pay for, on every order with a subtotal over £120. It is a full vial from the same stock we sell, not a sample. We choose which compound it is and it changes from order to order, so it cannot be requested, picked or swapped. It is added to your order as a £0 line and forms part of the order. It carries the same research-use-only conditions as everything else in the parcel. It is subject to availability and has no cash alternative, and we can change or withdraw the offer at any time before you place an order. So the only thing you do not know in advance is which compound it is, and you find out when you open the box.

You can pay instantly by bank transfer through our open-banking checkout (powered by fena, an FCA-regulated payment institution), you approve the payment in your own banking app, and no card or banking details ever touch our site. Alternatively, place the order and we email payment instructions; orders ship once payment is confirmed.

Yes. Until your order is packed and labelled you can cancel it yourself: open the order from your confirmation email or your account and press Cancel order. Nothing is sent, and if you had already paid we refund the full amount to the account it came from. Once the parcel is packed or on its way the button is gone, and the right to change your mind below applies instead.

If you are buying as a consumer, yes: you have 14 days from delivery to cancel, without giving a reason, under the Consumer Contracts Regulations 2013. Tell us within 14 days, send the sealed vials back within 14 days, and we refund the goods plus the original delivery charge within 14 days. Return postage is at your cost unless the item was faulty or wrong. Opened vials are the one exception: our vials are sealed sterile, and regulation 28(3)(b) puts sealed goods that cannot be resold once unsealed, for health and hygiene reasons, outside the cancellation right.

That is not a change of mind and it is on us. Tell us with your order number, the batch number and a photo if the problem is visible. Under the Consumer Rights Act 2015 you can reject faulty goods for a full refund within 30 days of delivery, and we pay return postage on anything faulty, damaged or wrongly supplied.

Yes. Every price on the site includes UK VAT at the applicable rate, currently 20%, so the figure you see is the figure you pay. A VAT invoice is available on request: email us your order number.

No, guest checkout works fine, and you can still view your order confirmation afterwards. An account adds order history, saved addresses, faster checkout, and instantly-published verified reviews, so it's worth having if you plan to reorder.

Yes, research peptides can be lawfully supplied in the UK as chemical reference materials for laboratory research. What is not lawful is supplying or buying them for human consumption: they are not MHRA-authorised medicines. By purchasing you confirm you are buying for laboratory research only, and our terms of sale make the same restriction binding on every order.

No. Nothing sold on this site is for human or veterinary use. Our products are not drugs, foods, cosmetics or dietary supplements. They are supplied exclusively for in-vitro laboratory research by qualified professionals, and we do not provide dosage or administration guidance of any kind.

Pepts is a UK company, and our registered name, company number, registered office and VAT number are in the footer of every page and at the top of the terms of sale. The contract for every order is with that company, it is governed by the law of England and Wales, and your statutory rights as a consumer apply in full.

No marketing email you did not sign up for, and no cross-site tracking, retargeting or advertising pixels of any kind. The only optional cookies we set are Google Analytics, which counts visits, and a Google Ads tag, which tells us when one of our own adverts led to an order; both stay switched off unless you accept them in the banner, and declining changes nothing about how the shop works. The cookie policy lists every cookie by name.