From the Guidelines
It is strongly advised against taking L-arginine and L-citrulline with Tadalafil (Cialis) due to the potential for additive effects that could lead to excessive blood pressure lowering and increased risk of hypotension, dizziness, fainting, headaches, or priapism. When considering the combination of these substances, it's crucial to understand their mechanisms of action. Tadalafil inhibits PDE5 enzymes, while L-arginine and L-citrulline serve as precursors to nitric oxide production, which relaxes blood vessels and improves blood flow. The interaction between these substances could potentially cause dangerous hypotension, as noted in guidelines that advise against administering nitrates to patients who have received a phosphodiesterase inhibitor for erectile dysfunction within the last 24 hours (48 hours for tadalafil) 1. Key points to consider include:
- The potential for increased nitric oxide production when combining L-arginine and L-citrulline with Tadalafil, which could lead to excessive vasodilation and hypotension.
- The lack of rigorous randomized trials on the long-term effects of oral arginine supplementation, particularly in the context of combining it with phosphodiesterase inhibitors like Tadalafil.
- The importance of consulting with a healthcare provider before combining these substances, as they can provide personalized advice based on specific health conditions, medication regimens, and treatment goals. Given the potential risks and the current state of evidence, the safest approach is to avoid combining L-arginine and L-citrulline with Tadalafil (Cialis) unless under the guidance of a healthcare provider. This precaution is in line with guidelines that prioritize caution when combining substances that can affect blood pressure and vascular health 1.
From the Research
Interactions between L-arginine, L-citrulline, and Tadalafil
- There is evidence to suggest that L-arginine and tadalafil can be used in combination for the treatment of erectile dysfunction, with a study showing that combination therapy was superior to monotherapies 2.
- L-arginine is a precursor to nitric oxide, which can help to relax blood vessels and improve blood flow, while tadalafil is a phosphodiesterase 5 inhibitor that also helps to increase blood flow to the penis.
- L-citrulline, on the other hand, can be converted to L-arginine in the body and may also have a role in increasing nitric oxide production, although its effects on erectile dysfunction are not as well studied as those of L-arginine and tadalafil.
- In terms of interactions, there is no direct evidence to suggest that L-arginine or L-citrulline interact with tadalafil in a way that would be harmful or contraindicated, although patients with certain medical conditions or taking certain medications should consult with their doctor before using these supplements together with tadalafil 3, 2, 4, 5.
Effects on Blood Pressure
- L-arginine and L-citrulline may have a blood pressure-lowering effect, with some studies showing that they can decrease systolic and diastolic blood pressure in patients with hypertension 5, 6.
- Tadalafil, on the other hand, can cause a decrease in blood pressure, particularly when used in combination with other medications that lower blood pressure 3.
- Patients with hypertension or other cardiovascular conditions should be cautious when using L-arginine, L-citrulline, and tadalafil together, as the combined effect on blood pressure is not well understood and may increase the risk of hypotension.
Safety and Efficacy
- The safety and efficacy of using L-arginine, L-citrulline, and tadalafil together have not been extensively studied, and more research is needed to fully understand the potential interactions and effects of this combination 2, 4, 5, 6.
- Patients should consult with their doctor before using these supplements together with tadalafil, particularly if they have any underlying medical conditions or are taking other medications.