FAQ

Visit refillpen.com/help for all of our help videos.

1. Remove the pen cap, by pulling the cap off.
2. Unscrew the cartridge holder (the body of the pen) from the main pen body.
3. Ensure the piston rod is fully pushed in.
4. Insert the new cartridge into the holder, often with the metal-capped (threaded) end first.
5. Screw the cartridge holder back onto the main pen body until it is secure.

Here is a video on how to insert a new cartridge:

This video shows once your cartridge is loaded in how to prime it.

Once it is primed properly, if you do not remove the cartridge from the pen, it will be ready to use again without needing to be primed. If you are switching out cartridges in one pen, this will need to be done before each use.

Use the dose selector dial on the pen to select your desired dose. You can simply turn the dial backwards (counter-clockwise) to reduce the dose if you accidentally dial too high. You cannot, however, turn the dial back once the dose has been fully injected.

Try our peptide dosing calculator.

After pushing the injection button all the way in until the dose counter shows '0', you must keep the needle in your skin and hold the button down for a slow count of 6 to 10 seconds (10 seconds is a common recommendation). This ensures the medication is fully delivered and prevents it from leaking out of the injection site when you withdraw the needle.

If no drop appears after 2-3 attempts, the needle may be clogged or bent. Attach a brand new needle and repeat the priming steps.

If a drop still doesn't appear, the cartridge may not be properly prepped. You may need to use the RefillPen button like shown in the video below.

A hard-to-push button usually indicates a clogged or bent needle. Do not force it. Remove the needle, attach a new one, prime the pen, and try the injection again. Forcing the pen can damage the internal mechanism.

No, you must remove the needle after every injection. Leaving the needle attached can lead to air or contaminants entering the cartridge, medication leaking out, and the delicate pen mechanism failing.

When flying, always keep your pen and supplies in your carry-on luggage. Checked luggage can be exposed to freezing temperatures in the cargo hold, which will ruin the medication.

No. Even if covered, the temperature inside a car can quickly exceed the safe 86 Degree F limit, potentially within minutes. Never store the pen or cartridges in a car.

A reusable (or durable) injection pen is a device designed for multiple uses. It holds replaceable cartridges containing the medication (e.g., insulin, GLP-1s) and uses disposable pen needles. The pen features a dialing mechanism to accurately set and deliver the required dose.

While the initial purchase of a reusable pen is higher, replacement cartridges are often more cost-effective per unit of medication than buying an entirely new disposable pen, leading to long-term savings.

No, RefillPens do not use batteries, it is strictly a mechanical device.

Pen needles are strictly for single use. Reusing a needle dulls the tip, increases pain, and can lead to a blocked needle, infection, or damage the pen's internal mechanism.

This is usually caused by removing the pen too quickly. After pressing the injection button, hold the needle in the skin for a full 6-10 seconds to ensure the entire dose is absorbed and to stabilize the pressure.

The cost of a replacement cartridge is $1 per cartridge, and free shipping on orders over $59.

Reusable injection pens are often considered less painful than traditional syringes primarily because they use finer, shorter needles designed to minimize pain, deliver medication in a controlled and consistent manner, and are easier to handle, which helps reduce discomfort during injection. Additionally, many users experience less anxiety with pens, which can psychologically reduce the perception of pain.

Yes, RefillPen is your best option to purchase easy to use injectable pens. With various colors and types, as well as accessories and great support.

RefillPen.com is the best place to purchase colorful refillable pens online. And we continue to get new colors and offerings so keep checking to see if a new color is available!

RefillPen.com offers a wide variety of storage boxes. Ranging from holding 6, 15, and even 30, for all of your vial storage needs.

• V1 pens (slim body) - made from metal - go up to 80 units - closed cap injection which means you will see and feel the injection (you remove the cap to poke)
• V2 pens - made from metal - go up to 60 units - open cap injection which means you can do the injection with the cap on or off when you use it with the cap on with a 4,5 or 6mm needle tip the cap distracts the nerve endings in your skin so not only will you not see the needle but will feel it much less.
• V2.5 pens (longer and slimmer than the V2) - made from metal - go up to 60 units - open cap injection which means with a 4, 5 or 6 mm tip you won't see the tip, and the cap helps scramble the nerve signals so you feel less
• V3 pens (slim body) - made from metal - go up to 60 units - closed cap injection which means you will see and feel the injection (you remove the cap to poke)

Yes — peptide injection pens are designed to be beginner-friendly and are significantly easier to use than traditional vial-and-syringe methods. Most first-time users can administer a dose comfortably after one short walkthrough, either from their provider or the pen's instructions.

What makes them simple:

• You dial the prescribed dose on a numbered window — no drawing from a vial
• Most people describe the injection as a brief pinch or feel nothing at all.
• Subcutaneous sites only. Peptide pens inject under the skin — usually the abdomen, outer thigh, or back of the upper arm. No need to find a muscle or vein.
• Audible feedback. Most pens click as you dial the dose and click for each unit as it is being administered.

A peptide pen is a reusable injection pen you refill from a standard 3 mL glass cartridge, instead of a single-use disposable you replace after one vial. You dial your amount in units on a numbered window — one click equals one unit — and the same pen keeps going as you swap in fresh cartridges. RefillPen makes them in models V1, V2, V2.5, and V3, in 50 color combinations.

In short: load a filled standard 3 mL cartridge into the pen, screw on a universal pen needle, prime until a drop appears, dial your amount in units (one click = one unit), and inject at a subcutaneous site. The step-by-step assembly, priming, and dialing instructions are above, and refillpen.com/help has short walkthrough videos.

The pen takes a standard 3 mL glass cartridge: remove the cap, unscrew the cartridge holder, make sure the piston rod is fully pushed in, drop the cartridge in (metal-capped threaded end first), and screw the holder back on until secure. For filling the cartridge itself, see our 3 mL cartridge filling guide and the videos on the Help page.

A peptide pen is reusable hardware for drawing and injecting precise, small-volume subcutaneous doses from a refillable 3 mL cartridge — the reusable alternative to a single-use disposable pen. The peptide community chooses it for dosing accuracy and low per-dose cost, since sterilized 3 mL cartridges are about $1 each.

The pen is reusable hardware meant to be used again and again — you replace the low-cost 3 mL cartridge, not the pen. With basic care, one RefillPen stays in service across many cartridges.

It depends on what you want: the V1 for the widest range (up to 80 units), the V3 for a solid metal closed-cap pen, or the V2.5 Slim Hybrid for a lighter body that keeps the needle hidden. Our Best Reusable Peptide Pen guide compares the V1, V2, V2.5, and V3 side by side.

Each click advances the dose by one unit, and the number shown in the dose window is the units you have dialed. On the pen's 100-unit scale, one unit equals one click equals 0.01 mL drawn.

RefillPen accepts universal pen needles — the standard screw-on pen needle used across injection pens — so a wide range of pen-needle lengths and gauges fit. Needle size is a personal choice; follow your own provider's guidance.

Directly from RefillPen at refillpen.com — the V1, V2, V2.5, and V3 pens, $1 sterilized 3 mL cartridges, Halo holders, travel cases, and the rest of the system. Most orders ship the same day, with free shipping over $59.

On a RefillPen, one click equals one unit. The exact number of clicks for your dose depends on your concentration — the free peptide dosing calculator works it out from your peptide amount, water volume, and target dose.