Investigation of a complex plant extract for mild to moderate erectile dysfunction in a randomized, double‐blind, placebo‐controlled, parallel‐arm study

Abstract

Study Type – Therapy (RCT) Level of Evidence 1b OBJECTIVE To assess the effects of a complex plant extract (Prelox®, a formulation of pine bark extract and l‐arginine aspartate; Horphag Research UK Ltd, London, UK) on erectile dysfunction (ED) in men, as sexual desire typically persists in ageing men, while their erectile and endothelial function gradually declines. PATIENTS AND METHODS In this double‐blind, placebo‐controlled study we assessed the effects of Prelox in 124 patients (aged 30–50 years) with moderate ED over an investigational period of 6 months. The International Index Of Erectile Function (IIEF) was used to quantify changes in sexual function. RESULTS The erectile domain of the IIEF (questions 1–5 plus 15) improved with Prelox from a baseline mean (sd) score of 15.2 (6.6) to 25.2 (2.1) after 3 months and 27.1 (2.1) after 6 months of treatment. In the placebo group there was an increase from a baseline score of 15.1 (7.0) to 19.1 (3.0) and 19.0 (3.1) after 3 and 6 months, respectively. The effects with Prelox were statistically significant compared with placebo (P < 0.05). Mean (sd) total plasma testosterone levels increased significantly from 15.9 (2.3) to 18.9 (2.6) nmol/L (P < 0.05) after 6 months with Prelox, compared to an increase from 16.9 (2.4) to 17.3 (2.3) nmol/L in the placebo group. CONCLUSION This study shows that Prelox is effective for improving erectile function, and that this effect persists on continuous therapy for up to 6 months. Moreover, there is some evidence that erectile function continues to improve the longer the therapy is used.

The Polyphenolic Antioxidant Resveratrol, the Carotinoid Lycopene, and the Proanthocyanidin Pycnogenol

“…Total plasma testosterone levels increased significantly after 6 months of treatment compared to the placebo group. 78 Similar findings were reported in the following sources: Oral administration of L-arginine in combination with Pycnogenol causes a significant improvement in sexual function in men with ED without any side effects. 79 …”

Nutraceuticals for Fertility and Erectile Health: A Brief Overview of What Works and What Is Worthless

“…An impressive amount of clinical data has been garnered for the use of L-arginine aspartate at a lower dosage (2,800-3,000 mg) when used with pycnogenol (80 mg) [140][141][142]. The most commonly tested supplement in this form is Prelox (Horphag Research Ltd, London, UK).…”

“…The clinical trial that has established Prelox as a definite nutraceutical option for men with mild to moderate ED in my opinion and arguably one of the better nutraceutical options for ED was based on a 6-month randomized, double blind trial, placebo-controlled parallel-arm study (n ¼ 124, mean age 44 years) [142]. Men in this trial had IIEF scores at baseline of 11-17, and diabetics and those with severe hypertension were excluded.…”

Late Onset Hypogonadism, Testosterone Replacement Therapy, and Sexual Health in Elderly Men

“…The study did not indicate specific phytotherapeutic agents utilized. In another trial, younger male subjects (age 30-50 years) were given a proprietary product containing pine bark extract and l-arginine aspartate [52]. Subjects receiving active therapy had statistically significant improvements in erectile function and serum testosterone levels compared to controls.…”