L-arginine is not currently recommended by UK clinical guidelines for the management of erectile dysfunction (ED) due to a lack of robust evidence on its efficacy and safety. The standard first-line pharmacological treatments endorsed by UK guidelines are phosphodiesterase type-5 (PDE-5) inhibitors such as sildenafil, tadalafil, vardenafil, and avanafil, which have well-documented efficacy in improving erectile function by enhancing nitric oxide-mediated vasodilation NICE CKS. These guidelines explicitly note the absence of good-quality evidence supporting herbal or complementary medicines, which would include L-arginine supplements, and do not recommend their use NICE CKS.
From a mechanistic standpoint, L-arginine is a precursor of nitric oxide, a key mediator involved in penile erection through vascular smooth muscle relaxation. Some recent research publications outside the UK guideline context have explored novel or adjunctive therapies for ED, such as exosome therapy and complex management strategies, especially in diabetic erectile dysfunction, but these do not provide conclusive clinical evidence supporting L-arginine supplementation specifically Feng et al. 2023Ma et al. 2024. Consequently, while L-arginine’s role as a nitric oxide donor is theoretically plausible, current clinical guidance prioritises PDE-5 inhibitors and lifestyle modification, with no formal endorsement for L-arginine.
In clinical practice, it is advisable to focus on evidence-based treatments and to counsel patients about the limited and inconclusive data on L-arginine supplements, ensuring management aligns with established NICE-endorsed guidelines and expert opinions NICE CKS.
Key References
- Alprostadil SmPC
- Avanafil SmPC
- Vardenafil SmPC
- Aviptadil with phentolamine mesilate SmPC
- CKS - Erectile dysfunction
- (Feng et al., 2023): Erectile dysfunction and exosome therapy.
- (Ma et al., 2024): The multifaceted nature of diabetic erectile dysfunction: uncovering the intricate mechanisms and treatment strategies.