Retatrutide 40mg Injection Pen Kit
£220.00
Synedica Retatrutide® Injection Pen Kit is the world’s most advanced weight loss solution. Retatrutide is an advanced medication which suppresses appetite leading to significant weight loss. It does this by mimicking the effects of the GLP-1, GIP and glucagon receptors, which are natural hormones that makes humans feel full from eating much smaller portions of food.
The Synedica Retatrutide® 40mg Injection Pen Kit contains 1 pen, 12 disposable needles and an instruction booklet.
Each pen has 40mg which can be delivered across 4 full doses of 10mg, or in increments of 2.5mg, 5mg, 7.5mg or 10mg.
Recommended dosage is 2.5mg for the first 4 weeks, then 5mg for the next 4 weeks. After 8 weeks the weekly dosage may be increased to 7.5mg or 10mg if necessary.
⚠️ Important Notice
All products are produced exclusively for controlled laboratory research and development applications.
Not for human or animal consumption.
🔬 Suitable R&D Applications
🧪 Stability Testing
Thermal, enzymatic, and oxidative degradation studies
Shelf-life evaluation & formulation robustness
⚗️ Formulation Development
Enhances solubility, bioavailability, and structural integrity
Tailored for injectable, topical, and research-grade use
🧩 Excipient Compatibility Testing
Evaluates interactions between peptides & inactive components
Ensures safety, stability, and performance
🔒 Protease Resistance Evaluation
Assesses susceptibility to enzymatic breakdown
Supports development of more durable peptide products
📦 Encapsulation & Carrier Systems
Liposomes, microspheres, and other delivery vehicles
Protects peptides & enables controlled release
💉 Administration Route Assessment
Optimized for:
Parenteral delivery (injectables)
Dermal absorption (cosmetic/topical)
In vitro research applications
Retatrutide 40mg is the largest format we supply and the best value per milligram in the range. The kit is priced at £220, which works out at £5.50 per milligram against £7.00 for the 20mg pen, and it reduces a multi month supply to a single refrigerated delivery. Supplied for laboratory research use only and not for human or veterinary consumption.
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Table of Contents
Retatrutide 40mg Kit Specification
| Specification | Detail |
|---|---|
| Compound | Retatrutide, also written LY3437943 |
| Total content | 40mg per kit |
| Format | Injection pen kit |
| Price | £220 |
| Cost per mg | £5.50 |
| Purity | Above 98 percent, batch documented |
| Storage | 2 to 8 degrees refrigerated, never frozen |
| Classification | Research use only, not for human consumption |
Why Retatrutide 40mg Is the Best Value Format
Peptide pricing does not scale linearly with content. A large share of the delivered cost sits in the device, the sterile fill, the refrigerated logistics and the packaging rather than in the compound, so those fixed costs spread across more milligrams as the format grows. That is the entire reason retatrutide 40mg lands at £5.50 per milligram while a 10mg pen elsewhere runs £8.00 to £11.00.
Put concretely, buying 40mg as four separate 10mg pens costs roughly £320 to £440 at prevailing UK prices. The same quantity as this kit costs £220. That is £100 to £220 saved on identical material, before counting the shipping and cold chain exposure avoided. Full market figures are in our retatrutide price UK index.
What Is in the Kit
The kit is supplied as a complete unit rather than a bare cartridge, so nothing else needs sourcing separately before work can begin.
- 40mg of retatrutide, batch numbered on the device itself.
- The pen device with its dial dosing mechanism.
- Instructions covering priming and dial operation for that specific device.
- Insulated packaging with a coolant pack for transit.
- Batch documentation referencing the certificate of analysis for that lot.
How Far 40mg Goes
Mapped against the amounts actually used in the published trials, retatrutide 40mg spans a substantial period, which is what makes it suitable for extended protocols rather than short pilots.
| Weekly amount from the trials | Weeks covered by 40mg |
|---|---|
| 1mg | 40 |
| 2mg | 20 |
| 4mg | 10 |
| 8mg | 5 |
| 12mg | 3.3 |
The Phase 2 obesity study published in the New England Journal of Medicine used target amounts of 1mg, 4mg, 8mg and 12mg weekly, all reached by stepped escalation. Ongoing Phase 3 work is registered on ClinicalTrials.gov. Complete schedules are in our dosage chart guide.
Preparation and First Use
Prime the device exactly as its own instructions specify before the first delivery. An unprimed pen delivers less than the dial indicates, and on a 40mg kit that error propagates across every subsequent measurement rather than being confined to one pen. Confirm the dial increment matches the amounts your protocol requires, because a coarse device cannot be made fine after purchase.
Use a fresh needle for each draw. Reusing needles risks contaminating a cartridge that is intended to last months, which is a materially larger loss than spoiling a small pen. Device mechanics across formats are compared in our retatrutide pen guide.
Long Term Storage Across a Larger Quantity
A larger quantity means a longer exposure window, so storage discipline matters more here than on any smaller format. The compound is in solution throughout, and time at temperature accumulates.
- Refrigerate between 2 and 8 degrees continuously and never freeze, since freezing denatures the peptide as reliably as heat.
- Keep the kit in its original carton, away from direct light.
- Choose a stable position in the refrigerator, away from the door where cycling is worst.
- Avoid repeated temperature excursions. Across a multi month kit these accumulate in a way they do not on a pen used up in a fortnight.
- Record the storage location and any deviation in your log on the day it happens.
Batch Documentation and the Purity Question
Every retatrutide 40mg kit carries a printed batch number on the device, cross referenced to a certificate of analysis that names the issuing laboratory and the test date rather than reproducing a generic template.
Purity above 98 percent is claimed across this whole market and it is worth understanding what that figure does not cover. Purity describes what proportion of the material present is the intended compound. It says nothing about how much material is present, which is the variable that determines whether a kit actually holds 40mg. That is why fill volume and concentration are both stated, so the total can be confirmed by arithmetic rather than taken on trust.
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Fewer Deliveries Means Less Cold Chain Risk
The value argument for retatrutide 40mg is not only about price per milligram. Every separate delivery is a separate transit event, and transit is where cold chain failures happen. Four deliveries of 10mg means four chances for a parcel to sit in a warm depot over a weekend. One delivery of 40mg means one.
That risk is not hypothetical. Cumulative time at temperature is the variable that most reliably decides whether a peptide still matches its label at the point of use, and it is invisible to inspection. A pen that spent three days warm looks identical to one that did not. Consolidating into fewer deliveries is the cheapest available reduction in that risk.
Retatrutide 40mg Against the Smaller Formats
| Format | Price | Cost per mg | Deliveries per 40mg | Verdict |
|---|---|---|---|---|
| 10mg pen | £80 to £110 elsewhere | £8.00 to £11.00 | 4 | Poor value, we do not stock it |
| 20mg pen | £139.99 | £7.00 | 2 | Good first order |
| Retatrutide 40mg kit | £220 | £5.50 | 1 | Best value overall |
The case against the smallest format is set out in our retatrutide 10mg guide. If you are weighing labels rather than sizes, the VLS guide and Viogen guide explain what brand names prove. Background on the compound itself is in the reta peptide guide, and the reported safety data with its limits is in the side effects guide.
Ordering and Arrival Checks
Kits ship from the United Kingdom in insulated packaging with a coolant pack. On arrival, refrigerate immediately, check the batch number on the device against the paperwork, and record the packaging condition including whether the coolant was still cold. Contact us before opening the device if anything looks wrong.
Supplier checks worth running before any peptide order are in our buy retatrutide UK guide. The full catalogue is on the shop page. Peer reviewed background on this compound class is indexed on PubMed.
The Economics of Buying Retatrutide 40mg at Once
Committing to a larger quantity is a real decision, not just a discount, and it is worth setting out the trade honestly. The saving is genuine and so is the exposure: a single kit concentrates the whole outlay into one delivery and one storage location, so a cold chain failure costs more when it happens.
| Buying pattern | Total outlay | Cost per mg | Deliveries | Risk profile |
|---|---|---|---|---|
| 4 x 10mg elsewhere | £320 to £440 | £8.00 to £11.00 | 4 | Loss spread thin, cost highest |
| 2 x 20mg pens | £279.98 | £7.00 | 2 | Balanced |
| 1 x 40mg kit | £220 | £5.50 | 1 | Cheapest, loss concentrated |
For most laboratory work the concentration of risk is the lesser problem, because it is manageable with a refrigerator that holds temperature and a log that records deviations. The cost difference is not manageable, it is simply paid or not paid. That is why retatrutide 40mg is the default recommendation for anything beyond a short pilot.
When the 40mg Kit Is the Wrong Choice
There are cases where the larger kit is not the right purchase, and it is more useful to name them than to pretend the best value option suits everyone.
- A first order from any new supplier, where the sensible move is to verify batch documentation and cold chain on a smaller quantity before committing.
- Work with a defined short duration, where the remainder would sit in storage degrading rather than being used.
- No reliable refrigeration, in which case a large quantity simply gives more material to spoil.
- A protocol still being designed, where the required amounts and therefore the required dial increment are not yet settled.
In any of those cases the 20mg pen at £139.99 is the better starting point, and the kit becomes the sensible reorder once the supply route has proved itself.
Recording a 40mg Kit Across Its Working Life
A kit that lasts months needs a record that lasts months. The single most common gap we see is a log started enthusiastically and abandoned by week three, at which point the batch has no usable history and any anomaly later becomes impossible to attribute.
- Batch number as printed on the device, cross checked against the certificate of analysis on the day of arrival.
- Arrival date, packaging condition, and whether the coolant pack was still cold when the parcel was opened.
- Storage position, and the measured temperature range rather than the assumed one.
- Priming performed on first use and the volume discarded to prime.
- Each amount delivered with its date, recorded as delivered rather than as dialled.
- Every deviation, including brief refrigeration gaps, power interruptions and transport between sites.
Cumulative time at temperature is the variable that decides potency, and it can only be reconstructed from a contemporaneous record. Peer reviewed stability literature for this compound class is indexed on PubMed if you are building handling standards from published work rather than supplier claims.
Legal Position and Research Use Only
Retatrutide holds no marketing authorisation from the MHRA. It is not a licensed medicine in the United Kingdom, cannot lawfully be supplied for human use, and cannot be advertised with therapeutic claims under Advertising Standards Authority rules. This retatrutide 40mg kit is supplied for laboratory research use only and is not for human or veterinary consumption.
Published trial evidence comes from pharmaceutical grade material administered under supervision to a screened population, and does not transfer to research material used outside that setting. Anyone seeking treatment should speak to a registered UK prescriber about licensed options. Nothing on this page is medical advice.
Retatrutide 40mg FAQ
How much does retatrutide 40mg cost?
£220 for the kit, which is £5.50 per milligram and the best value format we supply.
Is retatrutide 40mg better value than the 20mg pen?
Yes. £5.50 per milligram against £7.00, and one delivery instead of two, which also halves the cold chain exposure.
How long does a 40mg kit last?
Against published trial schedules it covers 40 weeks at 1mg weekly, 20 weeks at 2mg, 10 weeks at 4mg and 5 weeks at the 8mg amount studied.
What is in the kit?
40mg of batch numbered retatrutide, the pen device, its priming and dial instructions, insulated packaging with a coolant pack, and batch documentation.
What purity is it?
Above 98 percent, documented per batch with the issuing laboratory and test date named.
How should a 40mg kit be stored?
Refrigerated continuously between 2 and 8 degrees, never frozen, in the original carton away from light and away from the refrigerator door.
Is retatrutide legal in the UK?
It may be supplied for laboratory research use only. It holds no MHRA authorisation and cannot lawfully be sold or supplied for human use.
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