Retatrutide 10mg / 20mg / 30mg / 40mg
Also known as Reta
Investigational triple agonist targeting GLP-1, GIP and glucagon receptors — 20mg, 30mg and 40mg lyophilised vials at ≥98% purity for in vitro research.
We reconstitute your peptide under sterile conditions and load it into a dial-a-dose Quick Pen, cold-shipped with screw-on needles and a clicks-per-mg guide.
For In Vitro Use Only — Not for Human Use
Every batch is independently HPLC & mass-spec tested. Certificate of Analysis is batch-numbered and matched to the vial you receive.
Overview
Retatrutide (LY-3437943) is an investigational triple-receptor agonist that combines activity at the GLP-1, GIP and glucagon receptors in a single 39-residue peptide backbone. Supplied as a sterile lyophilised powder in 20mg, 30mg and 40mg vials, each batch is verified to ≥98% purity by RP-HPLC and mass spectrometry.
Research
Retatrutide is used in vitro to study the combined pharmacology of incretin (GLP-1, GIP) and glucagon receptor signalling in a single molecule. Research groups compare it head-to-head against dual agonists (e.g. Tirzepatide) to characterise receptor bias, cAMP response, and peptide stability across long incubation windows.
Reta Pen UK — how to use a Retatrutide pen
Select the Pen format above and we prepare your 20mg, 30mg or 40mg Retatrutide vial as a pre-filled, calibrated dial-a-dose Reta pen in the UK, cold-shipped with a clicks-per-mg card.
- Step 1Bring the pen to room temperature
Take the pen out of the fridge 10–15 minutes before use. Cold solution is thicker and dispenses less accurately. Never microwave, warm in hot water or shake the pen.
- Step 2Inspect the cartridge
Hold the pen up to the light. The reconstituted Retatrutide should be clear and colourless with no visible particles or cloudiness. If it looks off, stop and contact us.
- Step 3Attach a fresh needle
Wipe the rubber septum with an alcohol swab, then screw on a new 32G 6mm pen needle. Always use a new needle each time — reused needles blunt, contaminate and cause dose loss.
- Step 4Prime the pen
Dial 2 units, point the needle upwards and press the plunger until a droplet appears at the tip. Priming clears the air gap so your first dose is a full dose. Repeat if no droplet appears.
- Step 5Dial the dose in clicks
Each click equals a fixed volume, and the mg-per-click depends on the vial strength and fill volume. Use the calibrated clicks-per-mg card in your box, or cross-check on our free reconstitution calculator.
- Step 6Dispense and hold
Press the plunger fully and hold for 6–10 seconds before withdrawing so the full dialled volume is delivered rather than left in the needle.
- Step 7Remove the needle and refrigerate
Unscrew and dispose of the needle in a sharps bin — never store the pen with a needle attached, as that lets solution leak and air enter. Return the pen to 2–8°C.
Reta pen FAQs (Retatrutide pens)
Bring the pen to room temperature, attach a fresh 32G 6mm needle, prime with 2 units until a droplet appears, dial your dose in clicks using the calibrated card supplied, dispense and hold for 6–10 seconds, then remove the needle and refrigerate at 2–8°C.
Peptides UK 4U supplies Reta pens (Retatrutide pens) from our UK facility. Choose your strength (20mg, 30mg or 40mg) and select the Pen format on this page — we handle reconstitution and bacteriostatic water and cold-ship it ready to use.
The Reta pen price is the vial price plus the Quick Pen preparation, shown as an all-in price when you select the Pen format on this page.
A Reta pen is a standard dial-a-dose injection pen pre-loaded with reconstituted Retatrutide, prepared in a controlled UK environment at a set concentration so the clicks-per-mg are calibrated before it reaches you. Reta is simply the common short-hand for Retatrutide.
Clicks-per-mg vary with vial strength. A calibrated clicks-per-mg card is included with every Reta pen we dispatch, and you can cross-check any dose with our free online calculator.
Reta pens ship in insulated cold packaging via Royal Mail Tracked 24. Orders placed before 2pm on a working day are dispatched the same day from our UK premises.
Once reconstituted, Retatrutide should be refrigerated and is generally stable for around 4–6 weeks. Keep the pen at 2–8°C between uses and away from direct light.
Yes — the pen uses standard screw-on pen needles. We recommend 32G 6mm needles and stock them on-site so you can add a pack at checkout.
Also researching Tirzepatide? See our Tirz pen guide and Tirzepatide vials UK and Semaglutide vials UK pricing page — 20mg, 40mg and 60mg, UK stock, same-day dispatch before 2pm.
