As a store that has sold Dr. Pen devices for seven years, the question we get most is not which pen to buy — it is which cartridge. This guide covers the pin counts available (12, 18, 24, 36, 42 and nano), what each one is actually for, and which ones fit your device.
What a cartridge does
Each cartridge holds a set number of fine needles that create controlled micro-channels in the skin. Those channels trigger the healing response that produces collagen and elastin, and they let serums penetrate further than they otherwise would. The cartridge is the part that touches your skin, and it is single use.
Dr. Pen makes cartridges to match a specific handpiece — A20 cartridges for the A20, M8 cartridges for the M8, and so on. The table below shows which pin counts are available for each device. If you are ever unsure which ones fit your pen, send us a photo and we will confirm it for you.
Which cartridge fits your device?
| Your device | Available pin counts |
|---|---|
| A20 | 12 · 14 · 18 · 24 · 36 · 42 · nano |
| M8 | 11 · 16 · 36 · 42 · nano |
| M8S | 12 · 18 · 24 · 36 · 42 · nano |
| A11 | 12 · 18 · 24 · 36 · 42 · nano |
| A6S | 11 · 16 · 36 · nano |
What each pin count is for
The number of pins changes how much skin you cover per pass and how the pressure is distributed. It does not change how deep the needles go — that is the depth setting on the device, and the two are easy to mix up.
Nano
Silicone-tipped cones rather than needles. They separate cells in the outermost layer instead of piercing into the dermis. Lovely for serum absorption, surface texture, pore appearance and maintenance between deeper sessions. Gentle enough for every second day.
11 and 12 pin
The most precise option. Fewer needles means pressure concentrates, which suits targeted work: individual scars, small areas, around the nose and mouth. Also the most popular choice for scalp and hair-loss treatment.
14, 16 and 18 pin
The balanced middle. Enough coverage to work a cheek or forehead without losing precision. If you want one cartridge that handles most things, this is the range to be in.
24 and 36 pin
Wider coverage for larger areas. You cover the same surface in fewer passes, and the pressure spreads across more contact points, which most people find more comfortable.
42 pin
Maximum coverage, gentlest feel. Suits sensitive skin, larger body areas, and anyone new to microneedling who wants to build confidence before going finer.
Is more pins better?
They do different jobs rather than better ones. More pins cover ground faster and feel gentler. Fewer pins concentrate the work where you point them. For a specific scar, a finer pin count will serve you better than a 42-pin cartridge, however comfortable that one feels.
Quick answer
- Targeted work, individual scars, scalp: 11 or 12 pin
- General face treatment: 14, 16 or 18 pin
- Cheeks, forehead, body: 24 or 36 pin
- Sensitive skin, large areas: 42 pin
- Serum absorption, maintenance: nano
Three things worth remembering
One cartridge, one session. They are sterile and single use. Cleaning does not restore them, and blunted needles tear the skin rather than piercing it cleanly.
Check the cartridge matches your pen before ordering. The table above covers every device we stock, and we are happy to confirm it for you.
Depth is set on the device, not chosen by pin count. Our needle depth guide covers which millimetre setting suits which concern.
Choosing between models rather than cartridges? Our model comparison guide covers every device we sell, and Dr. Pen M8 vs M8S looks at the two people ask about most.
Please speak with your doctor before purchasing any Dr. Pen product. This content is not intended to substitute for the advice of a qualified physician, pharmacist or other licensed healthcare professional.
