What is the difference between a V3 pen and a V5 pen?

The V3 dials 1–60 units per dispense; the V5 dials up to 80 units and adds a retracting needle mechanism that keeps the needle out of sight during use. Both take the same 3ml cartridges and the same pen needles.

V3 Peptide Pens UK — Compared & Explained

Q: Is a V3 pen reusable?

Yes. A V3 pen is a reusable injector pen: the 3ml glass cartridge inside it is replaced when empty, and the pen body is used again. This is the main difference from disposable pens, which are used once and replaced entirely.

Q: What cartridge does a V3 pen take?

The standard 3ml glass pen cartridge with a rubber stopper and crimped cap. It is the same cartridge format used across V1, V2, V3 and V5 pens, so cartridges are interchangeable between versions.

Q: What needles fit a V3 pen?

Standard screw-thread pen needles. The thread is universal across pen versions, so the same pen needles fit V1 through V5 pens — common research choices are 31G and 32G in 4–6mm lengths.

Q: Are all V3 pens the same?

Mostly, but not always. 'V3' is a generation name used by several manufacturers rather than a single regulated standard, so check the spec before buying: a 1–60 unit dial in 1-unit clicks, an aluminium body, the 3ml cartridge format and a standard needle thread are what the name should mean.

What a V3 Pen Is

A V3 peptide pen is a reusable, cartridge-fed injector pen: a metal-bodied device that holds a standard 3ml glass cartridge, dials a chosen volume in precise 1-unit clicks (1 unit = 0.01ml), and dispenses it through a screw-on pen needle. When the cartridge is empty you fit a fresh one — the pen itself is used for years.

Dial range: 1–60 units, 1-unit clicks
Unit volume: 1 unit = 0.01ml
Cartridge: 3ml glass, replaceable
Needle fitting: Standard pen-needle thread (31G/32G common)
Body: Aluminium, snap-on cap
Format: Reusable — replace cartridge, keep pen

The V3 became the default because it fixed the loose tolerances of earlier generations while staying simple: no electronics, no proprietary consumables, and every part of the consumable chain — cartridges and needles — is a standard format you can buy anywhere.

V3 vs the Other Versions

Version	Dial	Body	Worth knowing
V1 / V2	1–60 units	Metal or plastic	Still sold at lower prices. Same cartridge principle, but they predate the V3's refinements and exact spec varies by manufacturer batch — confirm cartridge format and needle thread before ordering.
V3	1–60 units	Aluminium	The current UK standard. Consistent spec, widest colour availability, easiest to source cartridges and spares for.
V4	1–60 units	Metal	Never established itself in UK retail stock — most ranges step straight from V3 to V5.
V5	1–80 units	Aluminium	The newest generation: a wider 80-unit dial and a retracting needle mechanism. Same 3ml cartridges and needles as the V3.

Fuller version-by-version detail, including photographs of each generation, is in the peptide pen versions guide.

The Pre-Purchase Checklist

Because "V3" is a generation name rather than a regulated standard, a listing carrying the name is not a guarantee of the spec. Five things to confirm before buying any V3 peptide pen in the UK:

Dial spec: 1–60 units in 1-unit clicks, with a clear window. If a listing doesn't state the dial range, ask.
Cartridge format: standard 3ml glass cartridge. Proprietary or unstated cartridge formats leave you stranded on refills.
Needle thread: standard pen-needle fitting, so 31G/32G needles from any supplier fit.
UK stock, not import: UK-held stock arrives in days and returns are workable; drop-shipped imports can take weeks and warranty claims rarely survive the distance.
Consumables from the same shelf: a supplier who also stocks cartridges, needles and cases can keep you running; a pen-only seller can't.

Compatibility

The quiet strength of the V3 format is that nothing about it is proprietary. The 3ml cartridge is the same across V1–V5 pens, the needle thread is universal, and cases sized for pen hardware fit every generation. If you move to a V5 later, every cartridge and needle you own carries over.

Buying a V3 Pen in the UK

We stock the V3 as our standard reusable pen — UK-held stock, same-working-day Royal Mail dispatch, cartridges, needles and cases on the same shelf, and multi-buy discounts applied automatically on quantity orders.

V3 Pen — current price & colours Complete V3 Kit

All hardware is supplied for laboratory and research use. Nothing on this page is medical advice, and no product here is a medicine or sold for administration to people.

Frequently Asked Questions

Is a V3 pen reusable?

Yes — the 3ml cartridge is replaced when empty and the pen body is used again. That is the difference from disposable pens, which are used once and replaced entirely.

What cartridge does a V3 pen take?

The standard 3ml glass pen cartridge with rubber stopper and crimped cap — the same format used across V1, V2, V3 and V5 pens, so cartridges are interchangeable between versions.

What needles fit a V3 pen?

Standard screw-thread pen needles; the thread is universal across versions. 31G and 32G in 4–6mm lengths are the common research choices.

What is the difference between a V3 and a V5 pen?

The V3 dials 1–60 units; the V5 dials up to 80 and adds a retracting needle mechanism. Both use the same cartridges and needles.

Are all V3 pens the same?

Mostly — but "V3" is a generation name used by several manufacturers, not a regulated standard. Run the checklist above on any listing before you buy.

V3.
Pens.

One pen, seven finishes