A Randomized, Placebo-Controlled, Double-Blind Study of Phyllanthus Amarus in Combination with Whey Protein Isolate on Skeletal Muscle Strength in Active Males

Purpose: Athletes often use dietary supplements to enhance their exercise performance. This study investigated the additive effects of Phyllanthus amarus (EB-PA) and whey protein isolate (WPI), compared to WPI alone or placebo on skeletal muscle strength in active males. Participants and Methods: A total of 121 healthy male participants, aged 20 to 35 years and engaged in moderate physical activity, were randomly assigned to one of three groups: placebo group (Microcrystalline cellulose [MCC] capsule and maltodextrin sachet), WPI group (WPI [40 g] and MCC capsule], or EB-PA + WPI group (WPI [40 g] and EB-PA capsule [500 mg]). All participants completed resistance training twice weekly for 30 days. The primary outcome was muscle strength, assessed by 1-repetition maximum (1-RM) for the upper and lower body. Secondary outcomes included muscle endurance, muscle flexibility, muscle mass, and grip strength. Results: At the end of study, combining the EB-PA with WPI showed significantly improved in both upper (18.02%) and lower body (17.62%) 1-RM strength compared to WPI [upper (9.24%) and lower body (9.02%)] as well as placebo [upper (4.39%) and lower body (3.39%)]. The EB-PA + WPI group achieved a 22.89% significant increase in muscle endurance compared to 11.47% increase in the WPI group. Additionally, statistically significant enhancements were observed in muscle flexibility and grip strength in the EB-PA + WPI group versus the other groups (p< 0.05). Conclusion: Combination of EB-PA and WPI after 30 days significantly enhanced muscle strength, endurance, flexibility, and grip strength in active males. This suggests the EB-PA enhances muscle strengthening effect of protein supplements. EB-PA was safe throughout the study.