Using Gelcaps for Pilling

If you’ve read the tips on pilling cats and you want to learn how to correctly use gelcaps then you’ve come to the right place!

Sizes and Materials

Gelcaps come in different sizes, colors, and are made from different materials.

Gelcaps are sized backwards, so that the lower the number, the bigger the capsule. Size 000 is the largest size manufactured and size 5 is the smallest. This chart gives a general size comparison of the different capsules.

  • Cats generally take sizes 3 through 5
  • If you’re not sure what size your cat can take, start with size 4
    • You can always cut size 4 smaller to match a size 5
    • Size 5 is about 3 times the price per capsule of sizes 3 and 4
    • Size 4 is generally large enough to accommodate all of your pill fragments in a single dose
  • Sizes 3 – 5 are almost never carried in local stores, so you’re pretty much guaranteed to need to buy them online
  • Most capsules are made of gelatin from animal sources, typically beef. If your cat has any allergies to animal proteins you’ll want to look specifically for “vegetarian” capsules
  • Gelcaps often come in a variety of colors as well as clear. The coloring is always food-safe dyes, but avoiding unnecessary dyes is often a good thing to do.

General Tips

  • If you’re in an “emergency” situation and need capsules now, there are a few things you can try
    • Check with your vet to see if they carry cat-friendly sizes of gelcaps
    • Check with a local compounding pharmacy and see if they’ll sell you a few capsules to get started (if they’re very nice they may give them to you for free)
    • Buy a bottle of Vitamin B12 in capsules in the smallest dose you can find (usually 250 mcg or 500 mcg)
      • Open up the gelcaps and remove the B12
      • Refill the capsules with the medicines your kitty needs
        • Anything you empty out of the capsules will leave remnants inside, so you need to be absolutely certain you’re not giving tiny amounts of toxic medicines to your cat

Shrinking Larger Capsules

Here’s one method for cutting larger capsules into a smaller size and filling them. The size gelcaps used in this video are larger than what cats would normally take, but are also readily available at most health food / herb / vitamin stores.

If you’ve purchased cat-sized gelcaps but your cat is having trouble with them you can follow this same method for cutting those capsules into a smaller size.

Filling Capsules

The easiest way to fill capsules is to work with a capsule machine that’s the right size for the capsules you have.

If you are in the USA you MUST be able to get DEA permission to purchase a capsule filling machine from some larger corporations such as Cap-M-Quik and Capsuline. This rule typically applies to machines that make 100 or more capsules at a time, but some sellers apply the rule to all their capsule machines regardless of the batch sizes they produce.

Using a Capsule Machine

This video shows how to use a capsule machine. It’s not explained, but the first pieces that are poured in are the capsule tops, and the second pieces poured in are the capsule bottoms. You can also manually place the capsules in the holes rather than using the shake-method shown.


  • I normally use a smaller scraper than the one in this video
  • My machines also came with tamp tools to use to pack the capsules tighter
  • I often use the machine to hold capsules that I’m not bulk-filling but am just adding single pill fragments to
  • Double-check each capsule at the end to be sure they’re snapped shut correctly
    • Size 5 gelcaps often require a second, manual snap to close them completely and sometimes they’re also misaligned so you have to replace the cap to get them to close correctly

You could also purchase the Torpac ProFill system, which is a base, funnel, and tamp. It looks like this system only does one capsule at a time. I read that it was around $79 (USD) but you have to email the company directly to get a quote. They deliver to the USA and internationally.

With the expansion of home 3D printing there are now a lot of sellers on Etsy or similar sites offering capsule machines. One seller has this machine for sizes 3 or 4 and another seller has this machine, also for sizes 3 and 4.

Capsule Trays

If you’re not ready to purchase a capsule machine you could try capsule holding trays instead. Capsule trays have also become much more widely available due to 3D printing. This tray comes in any size, including size 5! If you happen to own a 3D printer you can get the print instructions for that tray at The tamp tool is a little difficult to print, but the rest of the tray comes out very nicely.

*Capsules size 3 and 4 have nearly identical diameter but different height. If you’re working with both sizes, buy the tray for size 4. It will still hold your size 3 capsules, they’ll just be a little too tall to scrape powders into. If you buy size 3 your size 4 capsule will be too short to use with the tray.

Making a Capsule Machine or Holder

There are some free or cheap ways to make capsule holders at home too.

Cardboard Box Method

  1. Find any small box that is comfortable to work with
  2. Make a table-top style insert (like the one that came with my demo box)
  3. Punch holes in the correct size for your capsules in the top of the insert
  4. Make a solid bottom layer to attach to the insert – it needs a gap to give your pills a place to rest
  5. Attach the top and bottom pieces together (I used tape in this example)
  6. Put the pill holder back in the box base
  7. (Optional) Attach some non-slip material to the bottom of your box
  8. Fill all the capsules!

3D Printer Method

If you (or a friend) have a 3D printer you can also search models for capsule fillers on or any other popular site for sharing 3D printer designs. Capsule filling tools for sizes 3-5 are not widely available in commercial products, but many people have come up with different styles and designs that can be 3D printed.

Some Other Methods

  • Use some tiny funnels made for pilling
    • Or use the tips for pastry/piping bags instead
      • The link is just an example, you should be able to find the tips in any local grocery store or even a dollar/discount store
  • Use a micro scoop to fill small amounts of powders
  • Use a sticky note to make a solid but disposable funnel
    • Use one that’s very sticky so it doesn’t come apart
    • Roll the note so that the sticky edge is on the outside and makes the bottom part of the funnel
    • If you need a larger mouth on the funnel, snip off the tip to open it further
    • Put the bottom of the funnel in your gelcap
    • Drop the powder in
    • Tamp it down with something if you need to pack it tighter.
  • Use some sort of paper creased down the middle to make a sort of slide for the powder
    • Parchment paper
    • Sturdy printing or notebook paper
    • Pre-creased rolling papers for cigarettes
    • Weigh paper for lab scales
  • Convert an empty pill bottle into a capsule filler