Verified
Great documentation
Support answered a batch question within a few hours over email. Rare to get that level of response from a research supplier. Product itself is exactly to spec.
Marcus T.Berlin, DE · 21 Apr 2026
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In stockReta Pen
HPLC purity 99.75% · View certificate ↗40 mg · ≥99% purity
4.9
Pre-filled research auto-injector pen — 40mg.
£199.00GBP
£199.00 per pen · Tax calculated at checkout · Free tracked UK & EU shipping over £50
Bundle & saveVolume discount applied automatically
1
We accept
≥99% purity
3rd-party HPLC
CoA per batch
Fast UK shipping
Quality guarantee
Every batch is independently HPLC assayed. Certificate of Analysis available on request.
Every UK order includes — free
- ✓Bacteriostatic water — laboratory diluent
- ✓Batch certificate of analysis (HPLC)
- ✓Discreet, unbranded packaging
- ✓Tracked delivery — free on orders over £50
Full refund
if a batch is off-spec
Free reship
if lost or damaged in transit
Same-day dispatch
Mon–Fri, order before 12:00 UK
Research use only
for laboratory work
Analytical data
Specifications, documented.
Identity data cross-checked against PubChem; purity taken from the batch certificate of analysis.
CompoundRetatrutide
Also known asLY3437943
Molecular formulaC₂₂₁H₃₄₂N₄₆O₆₈
Molecular weight4731.42 g/mol
CAS number2381089-83-2
PubChem CID171390338
Purity (HPLC)99.75% — batch certificate of analysis
FormPre-filled research pen
Storage2–8 °C, protected from light
About this compound
Retatrutide
Triple GIP / GLP-1 / glucagon analogue
Half-life
≈ 6 days
First disclosed
2022
Retatrutide (LY3437943) is an investigational tri-agonist peptide activating the GIP, GLP-1 and glucagon receptors. Published data place it among the most potent incretin compounds reported in laboratory metabolic-pathway research.
Balanced triple-receptor agonism is studied in vitro for combined incretin- and glucagon-receptor signalling.
Research areas
Glucagon receptor signallingIncretin-pathway modelsPeptide pharmacology
Research literature
Research notice: supplied strictly as laboratory research material for in-vitro use. Not for human or veterinary use, and not a medicine, food or cosmetic. This page gives identification and quality information only — no usage instructions or medical advice.
Browse this research area
Reta Pen is a pre-filled research auto-injector pen supplied for in vitro laboratory use, supplied by MyPeptides for laboratory research use only.
The Reta Pen holds 40 mg of retatrutide (LY3437943), the investigational tri-agonist peptide that activates the GIP, GLP-1 and glucagon receptors, in a pre-filled, ready-assembled research pen.
Retatrutide is studied in laboratory metabolic-pathway research as one of the most potent incretin compounds reported, and is often compared with the dual agonist tirzepatide and the GLP-1 / glucagon agonist mazdutide. The same compound is also available as 5 mg and 10 mg lyophilised vials.
Dispatched the same working day when ordered before 12:00 UK time, tracked and free over £50. Store refrigerated at 2–8 °C, protected from light. For laboratory research use only.
Reta Pen — frequently asked questions
Straight answers on purity, handling, dispatch and research use.
What is Reta Pen?
Reta Pen is a pre-filled research auto-injector pen supplied for in vitro laboratory use, supplied by MyPeptides as a pre-filled research pen for laboratory research use only.
What is Reta Pen used for in research?
In cited literature, Reta Pen is studied in metabolic and receptor-signalling research programmes. It is not a medicine and is not intended for human or veterinary use.
What purity is MyPeptides Reta Pen?
Every batch is third-party HPLC assayed at ≥99% purity. A signed certificate of analysis is available on request after checkout.
How should Reta Pen be stored?
Store refrigerated at 2–8 °C, protected from light. Do not freeze once assembled. Follow your lab's SOP for handling research auto-injectors.
Do you ship Reta Pen to the UK and EU?
Yes — tracked Royal Mail and DPD dispatch across the UK and EU, with free shipping on orders over £50. Weekday orders placed before 12:00 UK time ship the same day.
Reta Pen reviews
Verified feedback from qualified researchers across the UK & EU.
5.0(6 reviews)
Swipe
Verified
Great documentation
Support answered a batch question within a few hours over email. Rare to get that level of response from a research supplier. Product itself is exactly to spec.
Marcus T.Berlin, DE · 21 Apr 2026
Verified
Trust these guys
Documentation is what sold me. Independent CoA per batch, clean HPLC traces. Reconstitution behaved exactly as expected. Solid supplier for research use.
Amelia S.Edinburgh, UK · 3 May 2026
Verified
Exactly as described
Ordered late Monday, arrived Wednesday morning in the UK. Packaging was cold-protected and every vial sealed correctly. CoA matched the batch number on the label.
Anton V.Vienna, AT · 26 Mar 2026
Verified
Solid product, will reorder
Everything about this feels professional - from the site to the packaging to the paperwork. Purity assay matches what is on the label. Will keep ordering.
Daniel B.Milan, IT · 21 Apr 2026
Verified
Quality packaging, quick dispatch
Ordered a bundle to save on shipping - all vials arrived in one insulated pack, labels identical batch, CoA covers the lot. Great value.
Ethan W.Dublin, IE · 21 Jun 2026
Verified
Fast UK shipping
Clean product, no discoloration, correct fill. Certificate of analysis was in the box AND emailed. Very straightforward experience.
Jonas F.Copenhagen, DK · 17 Jun 2026
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