L-Citrulline

L-citrulline is available in tablet form, in a concentration of 1000 mg. 

The product L-Citrulline Jarrow Formulas, distributed by Secom, contains citrulline in free form, combined with Quatrefolic – (6S)-5-MTHF, the metabolically active form of folate, and gamma-tocopherol, an isomer of vitamin E with antioxidant properties. This combination gives the supplement superior biological value, acting synergistically on cardiovascular, liver, and muscle health.

L citrulline has multiple indications, validated by clinical and practical studies:

• Supporting cardiovascular function – by increasing nitric oxide production, it causes vasodilation and lowers blood pressure.
• Adjuvant in erectile dysfunction – improves penile blood flow and may be a natural alternative to conventional therapies.
• Improving athletic performance – increases oxygenation and the use of branched-chain amino acids (BCAAs) during exercise, contributing to muscle mass growth.
• Liver detoxification – participates in the urea cycle, facilitating the elimination of ammonia and supporting liver function.
• Supports brain health – through the intake of Quatrefolic®, which crosses the blood-brain barrier and supports neural processes.

L citrulline is indicated for adults, 1 tablet of 1000 mg per day, taken with meals or as directed by a specialist.

It is important to follow the dosage in the package insert and consult your doctor if taking other medications at the same time.

L citrulline is contraindicated in the following situations:

• Patients undergoing antihypertensive treatment or taking nitrates, due to the risk of severe hypotension
• People with severe kidney or liver disease, without medical advice
• Known hypersensitivity to any of the excipients or active ingredients

Monitoring vitamin B12 levels is recommended in elderly people, as folic acid can mask pernicious anemia. 

Long-term administration should be correlated with the evaluation of the metabolic profile and blood pressure.

Dietary sources of citrulline (watermelon, pumpkin, nuts) can supplement the intake from supplements.

In general, L-citrulline is well tolerated. However, mild reactions may occur, especially at high doses:

• Gastrointestinal discomfort (nausea, abdominal cramps, diarrhea)
• Mild headache or dizziness related to a drop in blood pressure
• Rarely, allergic skin reactions (rash, itching)

Most reactions are transient and disappear after adjusting the dose.

L-citrulline may interact with certain medications:

• Nitrates (e.g., nitroglycerin) – potentiate the vasodilator effect, increasing the risk of hypotension
• Antihypertensives – combination requires careful medical monitoring
• Medications for erectile dysfunction (e.g., sildenafil) – possible interactions with risk of excessive blood pressure drop

Data on L-citrulline overdose are limited. Administration of very high doses may cause:

• Marked hypotension, accompanied by dizziness or fainting
• Severe digestive disorders
• Electrolyte imbalances 

Treatment is symptomatic and includes hydration and blood pressure monitoring.

L citrulline should be stored in its original packaging at temperatures below 25°C, protected from moisture and direct sunlight. Keep out of the reach and sight of children. Observe the expiry date stated on the packaging.

• WebMD, L-citrulline
• Healthline, L-citrulline
• PubMed, L-citrulline supplementation: impact on cardiometabolic health
• MDPI, L-citrulline: a non-essential amino acid with important roles in human health