Oral arginine undergoes a “first-pass” liver effect, with the enzyme arginase degrading most of it before it reaches circulation — only 20–30% remains available for NO synthesis. Citrulline bypasses the liver, is absorbed by the intestine, and is converted to arginine in the kidneys, escaping liver breakdown entirely. Result: 3g of citrulline raises plasma arginine as much as 6–9g of oral arginine — 2 to 3 times more effective.

Citrulline is one of the most clinically studied sports supplements. Published results show increased time to exhaustion in high-intensity endurance exercise, significant increases in bench-press reps after citrulline malate supplementation, and reduced post-workout muscle soreness (DOMS) within 24–48 hours. Study dosages range from 3 to 8g/day, taken 20–30 minutes before training.

BioKyowa is Kyowa Hakko Bio’s raw-material brand, a world leader in pharmaceutical amino acids based in Japan. This citrulline is produced by natural fermentation (not chemical synthesis), over 99% pure (HPLC-verified per batch), non-GMO, allergen-free and pharmaceutical grade — the pure L-citrulline base form, not citrulline malate.

For sport: 3–6g in a shaker with water, 20–30 minutes before training. For cardiovascular support: 3g a day in a glass of water with a meal, over a 4–8 week course.

Not recommended for pregnant or breastfeeding women. If on antihypertensive medication, consult a doctor, as citrulline may potentiate the vasodilating effect.

90g or 500g: which format should I choose?

The 90g is a discovery format (2–4 weeks); the 500g is the economical choice for regular athletes (2–4 months). The formula is identical.

Citrulline in the morning or before training?

For sport: 20–30 minutes before training. For cardiovascular support: in the morning with breakfast. Both uses can be combined.

Herba Barona is an independent specialist supplement shop in the heart of Paris — established in 2006. What you order is genuinely on our shelves: we ship from our own stock, with no dropshipping and no long waits.

Visit us at 10 rue Théophile Roussel, Paris 12 — or use Click & Collect and pick up your order in-store. We also deliver across France and Europe. Friendly, expert advice in English from our team.

Where is the shop?

Herba Barona is at 10 rue Théophile Roussel, 75012 Paris — a two-minute walk from Ledru-Rollin (line 8), close to Bastille. Open Tuesday to Saturday, 9:30 am–6:30 pm.

Can I order online or collect in store?

Yes. We ship across France and Europe under the same conditions as our French store, or choose Click & Collect to pick up your order for free at our Paris shop.