Retatrutide Pens — 40mg · 8 Weekly Doses

The clinical-trial format, without the wait list

In the SURMOUNT-5 and TRIUMPH-4 trials, participants received retatrutide from a pre-filled injection pen — turn the dose dial, remove the cap, click, done. It’s the format Eli Lilly designed for real-world use, not laboratory research. Our retatrutide pens use the same mechanical principle: 40 milligrams of peptide in a sealed cartridge, delivering eight precise 5-milligram weekly doses.

If you’ve ever used an EpiPen, a Novolog pen, or a Wegovy pen, you already know how this works. Twist the dial to your dose. Screw on the tiny 32-gauge needle (comes in the box). Pinch a subcutaneous fold on your abdomen or thigh. Press the button. Count to ten. Remove. That’s the whole thing. Under a minute, once a week.

What comes in a pen kit

Every pen order ships with everything you need to run the full 8-week protocol without a single extra purchase from a Canadian pharmacy.

• Retatrutide 40mg pre-filled pen (quantity per your bundle) — each pen delivers eight 5mg doses
• Pen needles — 8 per pen, 32G × 4mm (BD Micro-Fine or equivalent Canadian medical-grade)
• Alcohol prep pads — 2 per anticipated injection (one for the pen tip, one for the injection site)
• Dosing card — printed titration schedule based on the clinical trial ramp-up protocol
• Sharps disposal note — instructions for finding your nearest Canadian sharps drop-off (usually your local pharmacy or health authority)
• Cold-chain packaging — insulated liner + gel ice packs, tested for 72 hours

How the pen mechanism actually works

The retatrutide pen is a mechanical dose-metering syringe. Inside the sealed cartridge is 2 millilitres of retatrutide solution at 20 mg/ml concentration. When you turn the dose dial, you’re advancing a lead screw against the internal plunger. Each click represents a specific volume — for our 40mg pens, one full turn advances the plunger 0.25ml, which delivers exactly 5mg of retatrutide.

The pen has a mechanical dose stop, meaning you cannot accidentally overdose. Once you dial past a click, you can only dial back by a specific mechanism (see the printed dosing card in your kit). The needle is single-use — remove and dispose after every injection.

The eight-week protocol

Most Canadian buyers run the standard SURMOUNT-style titration: 5mg per week for the first four weeks (that’s one full click), then 5mg per week for another four weeks. That’s exactly 8 doses per pen. Some experienced protocol runners titrate up more aggressively to 8-10mg per week — you can do this by dialling multiple clicks in the same injection, or by injecting twice in a session at different sites.

Pens versus vials — the case for pens

We stock and ship both formats because both formats deserve to exist. Vials are cheaper per milligram and more flexible for experimental protocols. Pens win on three specific fronts: simplicity, consistency, and travel.

Simplicity

Zero reconstitution. Zero syringe math. Zero risk of getting the concentration wrong. Turn dial, inject, done. If you’ve ever muttered “5mg divided by 5mg/ml is 1ml which is 100 units on a 100-unit syringe wait no, this is a 30-unit syringe so it’s 30 units…” — that entire calculation goes away with pens.

Consistency

Every dose is mechanically identical to the last one. There’s no human variability. Your Week 3 dose is molecularly the same as your Week 1 dose. For anyone tracking response curves over time, this consistency is scientifically useful.

Travel

You can’t easily travel with vials, syringes, and bacteriostatic water — try explaining that at Toronto Pearson security. A pen looks and behaves like a standard diabetes injection pen. It fits in a small insulated travel case, doesn’t require any special customs declaration when travelling domestically within Canada, and can be kept at room temperature for up to 21 days if you’re on an extended trip.

Storage — what happens after your pen arrives

An unopened pen goes straight into your fridge, ideally on a middle shelf where the temperature is most stable (not the door — the door swings between 4°C and 12°C every time you open it). At refrigerator temperature (2-8°C), our pens are guaranteed potent for 18 months from manufacture date — the exact expiration is printed on each cartridge.

Once you’ve done your first injection, the pen becomes an “in-use” pen. In-use pens can stay at room temperature (up to 30°C) for up to 21 days, or continue to be refrigerated. Do not freeze — freezing damages the peptide structure. If your pen has been frozen accidentally (rare but possible if you left it in the car in a Winnipeg winter), do not use it. Email us for replacement.