Metal Pen: the complete research guide
By the OzPeptides lab team · Updated 28 Sep 2026 · 26 wordsAbout the Metal Pen Purple
Metal Pen Purple is a reusable stainless dial-a-dose pen, $50. It is one of four finishes we stock.
What the pen is and is not
The metal pen is a reusable metal injector pen that takes pre-filled cartridges. It is a device rather than a peptide, which is why it has finishes rather than strengths — there is nothing in it until a cartridge goes in.
It is imported hardware and the one product in this catalogue that is not made in our Australian lab. The peptides that go in the cartridges are made here; the pen itself is not.
What goes in it
Any peptide we stock can be supplied as a pen cartridge at no extra cost (or $5 more per vial while a sale is running). We reconstitute it here, so the cartridge arrives as a solution ready for the pen rather than as a powder that needs mixing first.
That removes the handling step where most errors happen: directing diluent down the side of the vial, swirling rather than shaking, and waiting for the cake to dissolve fully before drawing. A cartridge also needs no bacteriostatic water, which is worth knowing before adding a bottle to the order.
Finishes
The pens come in black, pink, purple and silver, and the finish is the only difference between them — same device, same cartridges, same mechanism. Each finish has its own page because each is its own product code, not because they behave differently.
A pen is a durable item rather than a consumable. It is bought once and reused across cartridges, which is the practical argument for it over a syringe: the same measured mechanism every time, rather than reading a barrel by eye.
Pen or syringe
A syringe is read by eye: the barrel is marked in units, and the accuracy of a draw depends on how carefully the plunger is lined up with a mark. That is fine at larger volumes and progressively worse at small ones, where the error in reading is a large fraction of the number.
A pen dials a measured amount by mechanism rather than by sight, which removes that particular source of error and makes repeat draws consistent with each other. It is also faster, and it holds the cartridge rather than requiring a vial to be entered each time.
What it does not do is change the arithmetic. The amount in a cartridge and the concentration it was mixed at are the same facts they would be in a vial, and the reconstitution calculator applies either way.
Looking after it
The pen is a durable item bought once and reused across cartridges, which is the argument for spending on a metal one rather than treating the injector as a consumable. Keep it clean and dry, store it at room temperature, and use a fresh needle each time.
Cartridges are the consumable part. A cartridge in use belongs in the refrigerator between draws like any reconstituted vial, kept out of light, and the same weeks-rather-than-months window applies to what is inside it.
Wipe the cartridge septum with alcohol before each entry. A pen mechanism protects the measurement, not the sterility.
Ordering a pen with cartridges
The pen and the peptide are separate purchases: $50 for the pen, and the peptide at its vial price: supplying it as a cartridge rather than a plain vial costs nothing extra (or $5 more per vial while a sale is running). Buying the pen alone gives a device with nothing to put in it, which is occasionally what someone wants if they already have cartridges.
Cartridge orders need no bacteriostatic water, since we reconstitute them here. That is the practical difference from a plain-vial order, and it is worth checking before adding a bottle of diluent that will not be used.
Where the pen fits in an order
Every peptide in the catalogue is sold in three formats, and the pen belongs to one of them. A plain lyophilised vial is the cheapest and keeps longest, because a freeze-dried peptide stored cold and dry outlasts the same peptide in solution by a wide margin — it needs bacteriostatic water and a syringe. Mixed in vial arrives reconstituted and is drawn with a syringe. A pen cartridge arrives reconstituted and goes into a device like this one.
That is the whole decision: handle the reconstitution yourself, or have it done here as a cartridge at no extra cost (or $5 more per vial while a sale is running). Neither affects the peptide, which is the same batch tested the same way in all three formats.
Everything we make is synthesised and tested in our own lab in Blacktown, NSW, at ≥99% HPLC purity with 0 ppm heavy metals, and the batch number on each vial resolves to its own certificate. Orders placed before the daily cut-off dispatch the same day from Sydney.
Research use only
Everything on this site, this item included, is supplied for in-vitro and laboratory research only, to buyers aged 18 and over. Nothing in the catalogue is a medicine, and with the few exceptions named in the individual guides — where a registered product of the same molecule exists — nothing here is registered in Australia.
That framing is not a disclaimer bolted on the end. It is the reason this site carries arithmetic, batch certificates and honest evidence summaries rather than dosing protocols and before-and-after photographs, and it shapes what every page on it is allowed to say.
Metal Pen finishes compared
We stock Metal Pen in four finishes: Black at $50, Pink at $50, Purple at $50, Silver at $50.
Each finish has its own page. Same product, different finish.
About the Metal Pen
Metal Pen: a reusable stainless-steel dial-a-dose pen that takes our pen cartridges. It is equipment rather than a peptide — sourced, not made in our lab.