
L-Citrulline is a popular amino acid commonly used in sports nutrition, pre-workout formulas, and endurance supplements. If you’re making your own L-Citrulline capsules, choosing the correct capsule size is important because effective servings are often relatively large compared to many other supplements.
What Is L-Citrulline?
L-Citrulline is a naturally occurring amino acid found in foods such as watermelon. It is commonly used in fitness supplements because it helps support nitric oxide production and blood flow. Many people take L-Citrulline before exercise as part of a pre-workout routine.
L-Citrulline is usually available as a fine powder, making it suitable for encapsulation in empty gelatin or vegetarian capsules.
Best Capsule Size for L-Citrulline

Because L-Citrulline doses are typically measured in grams rather than milligrams, larger capsule sizes are usually preferred.
| Capsule Size | Approximate Capacity* | L-Citrulline Per Capsule |
|---|---|---|
| 000 | 1,000β1,400 mg | Best option |
| 00 | 600β950 mg | Good option |
| 0 | 400β700 mg | Acceptable |
| 1 | 300β500 mg | Less practical |
| 2 | 200β400 mg | Not recommended |
*Actual fill weight depends on powder density and filling method.

Recommended Choice
For most users, size 000 capsules are the most practical option because they can hold around 1 gram or more of L-Citrulline powder. This reduces the number of capsules needed per serving.
How Many Capsules Are Needed?

A common serving size is 3β6 grams of L-Citrulline.
3 Gram Serving
| Capsule Size | Capsules Needed |
|---|---|
| 000 | 2β3 capsules |
| 00 | 4β5 capsules |
| 0 | 5β7 capsules |
6 Gram Serving
| Capsule Size | Capsules Needed |
|---|---|
| 000 | 5β6 capsules |
| 00 | 7β10 capsules |
| 0 | 9β15 capsules |
As the table shows, larger capsule sizes significantly reduce the number of capsules required.
L-Citrulline vs L-Citrulline Malate
Many supplement manufacturers use L-Citrulline Malate instead of pure L-Citrulline. Citrulline Malate typically has a slightly different bulk density, so capsule capacities may vary slightly.
In most cases:
- Size 000 remains the preferred choice.
- Size 00 works well for smaller servings.
- Size 0 is suitable when capsule size needs to be reduced for easier swallowing.
Gelatin or Vegetarian Capsules?
Both capsule types work well with L-Citrulline powder.
Gelatin Capsules
Benefits include:
- Easy to fill
- Cost-effective
- Widely available
- Fast dissolution
HPMC Vegetarian Capsules
Benefits include:
- Suitable for vegetarians and vegans
- Plant-based material
- Low moisture content
- Excellent stability
Neither capsule type significantly affects the performance of L-Citrulline.
Tips for Encapsulating L-Citrulline

- Use a fine, dry powder for better filling consistency.
- Store capsules in a cool, dry environment.
- Consider size 000 capsules if taking larger daily doses.
- Use a capsule filling machine for faster production.
- Weigh a sample batch to confirm actual fill weights.


Frequently Asked Questions
Can L-Citrulline fit in a size 00 capsule?
Yes. Most L-Citrulline powders will fit comfortably in size 00 capsules, typically holding between 600 mg and 950 mg depending on density.
What is the best capsule size for L-Citrulline?
Size 000 is generally the best choice because typical servings are relatively large and require fewer capsules.
Is L-Citrulline powder easy to encapsulate?
Yes. L-Citrulline is usually a free-flowing powder that works well in both manual and semi-automatic capsule filling machines.
How many size 000 capsules are needed for 6 grams of L-Citrulline?
Most users will need approximately 5β6 size 000 capsules to achieve a 6 gram serving.

Conclusion
For most DIY supplement makers, size 000 capsules are the best capsule size for L-Citrulline, providing the highest capacity and requiring fewer capsules per serving. Size 00 capsules are a good alternative for those who prefer a slightly smaller capsule, while sizes 0 and smaller become less practical due to the number of capsules required for typical doses.

