Oral Supplementation of Dragon Power® Polygonatum had Beneficial Effects on Testosterone's Relationship with Cardiorespiratory Fitness and Erection: a Double-Blind, Placebo-Controlled Study

As age increases, the concentration of testosterone (male hormone) in the body gradually decreases, causing various aging conditions, such as physical strength. Among them, the Chinese herbal medicine Polygonatum kingianum (PK) can very well improve physical strength and resist fatigue. The purpose of this study is to explore whether PK can increase testosterone's relationship with cardiorespiratory fitness and erection. Subjects were randomly assigned to either the placebo group (n=25) or the PK group (n=25). Subjects were required to ingest 50 mL of the test product daily for a duration of 4 weeks. Cardiorespiratory endurance and blood biochemical values were analyzed at week 0, week 2, and week 4. After the subjects took it for 4 weeks, the results showed that PK extract drink increased testosterone 14% compared to the placebo group, and without any side effects on liver and kidney function. After taking PK extract drink for 2 and 4 weeks, the cardiorespiratory endurance index was significantly improved by 3.7% and 6.2%, and phosphodiesterase 5 (PDE5) expression was significantly decreased by 23.3% and 28.9% compared to placebo group. PK extract drink increased testosterone and was harmless to humans, and improved physical strength, erectile function.