Pens
V3 Peptide Pen (Closed Cap)
5.0· 9 verified reviews- Metal body
- Closed cap — needle visible
- Simple to load and dial
- Most orders ship same day
- Free shipping over $59
- Ready to use on arrival
- 7-day guarantee
Every pen comes with a 3 mL cartridge. Starter tools are included once per order.
The V3 is a metal, closed-cap reusable peptide pen that's simple to use, load, and dial accurately — you'll see the needle as you inject. It uses the same standard 3 mL cartridge and universal pen needles as the rest of the line.
Simple, solid, metal
The V3 is a user-friendly metal pen with a closed-cap design — straightforward to load and dial, with the needle visible as you inject. RefillPen is reusable hardware built to be used again and again. When a cartridge runs out you swap the inexpensive 3 mL cartridge, not the pen — that's the whole idea behind a refillable peptide pen.
Accuracy you can trust
Accuracy is what the peptide community asks about most, and it's what our reviews single out. The dial advances one click at a time, and on the pen's 100-unit scale one click equals one unit (0.01 mL) — so the number you set is the number you draw.
Everything you need to start
Every RefillPen comes with one 3 mL cartridge, and every order includes a set of starter tools, so you can get started the day it arrives. Ordering several pens, for yourself or someone else? Each pen still gets its own cartridge, and you can add an extra starter tools set for $2 in your cart.
Common questions
How does a peptide pen work?
You load a standard 3 mL glass cartridge into the pen, attach a universal pen needle, and turn the dial to set your amount in units. On the 100-unit scale one click equals one unit (0.01 mL), so what you dial is what you draw. When the cartridge is empty you replace the cartridge, not the pen.
How long does a peptide pen last?
The pen is reusable hardware you keep and refill — you replace the low-cost 3 mL cartridge rather than the pen itself, so one pen stays in service across many cartridges.
What cartridges and needles fit?
Every RefillPen model uses the same consumables: standard 3 mL glass cartridges and universal pen needles. Individually sterilized 3 mL cartridges are about $1 each.
Is the needle visible when I inject?
The V3 is a closed-cap pen, so the needle is visible as you inject.
Not sure how many units to dial?
Use the free peptide dosing calculator on this site to find your exact units — enter your numbers and it returns the units (clicks) to set on the pen.
What's the difference between the V1, V2, V2.5, and V3?
All four are reusable peptide pens that share the same 3 mL cartridges and universal needles; they differ in cap style (open cap hides the needle, closed cap shows it), body and dial feel, and dose range. See the 'Best Reusable Peptide Pen' guide to compare them side by side.
Reviews
This pen is awesome. I am new to pens and had a v2. It was ok but felt clunky. This one is so much smoother. Use this with GHK-cu. No burning. No pain. I would suggest every one get this pen.
Great quality, responsive and fast shipping. The cost is exceptional for what you get. Great quality good customer support.
Pens are of very high quality! Customer service is however a whole other level! Extremely satisfied!
Great product and quality. Very happy with my purchase it can sooner then expected!!!!
Works great and smoother than the other one I purchased on Amazon!
Easy smooth push for comfortable injection. Very good quality!
Great pens. Smooth injection travel and easy to use.
Great products!superfast delivery!super happy
Loved it! You can heard click by click.
Complete your setup
Want the whole setup? Build a Starter Kit →
3ml Individually Packed Glass Cartridge For Pen
The $1 sterilized 3 mL glass refill that fits every RefillPen.
Halo Cartridge Holder
A filling block that holds your cartridge steady for a clean, bubble-free fill.
Color: Black
Spacers for Cartridges - 5 Count
Drop-in spacers that clear the dead space so you draw every last drop.
Spacer Color: Red
Number Labels
Slide-on numbers so every pen shows your units at a glance.
Color: Pink
RefillPen Labels
Slide-on labels so you can tell at a glance what's loaded in each pen.