A proprietary blend of flower head and bark extracts increases muscle strength and enhances endurance in young male volunteers: a randomized, double-blinded, placebo-controlled trial.

BACKGROUND

The demand for safe and efficacious botanical formulations to increase muscle mass, strength, and stamina is increasing among athletes and the general population. The nutraceutical supplements of medicinal plant origin exert minimal health concern.

OBJECTIVE

This randomized, double-blind, placebo-controlled study was aimed to evaluate the ergogenic potential of a proprietary, standardized formulation (LI12542F6) of flower head and stem bark extracts.

METHODS

Forty male participants 18-40 years of age were assigned to receive either a placebo ( = 20) or 650 mg/day LI12542F6 ( = 20) for 56 days. All participants performed a fixed set of resistance exercises during the intervention. The primary endpoint was the change from baseline muscle strength, assessed by one-repetition maximum (1-RM) bench and leg presses, and handgrip strength. The secondary endpoints included cable pull-down repetitions, time to exhaustion on a treadmill, mid-upper arm circumference (MUAC), body composition using dual-energy x-ray absorptiometry (DEXA), and free testosterone and cortisol levels in serum.

RESULTS

Fifty-six days supplementation of LI12542F6 significantly improved baseline bench press ( < 0.0001), leg press ( < 0.0001), handgrip strength ( < 0.0006), number of repetitions ( < 0.0001), and time to exhaustion ( < 0.0008), compared to placebo. Post-trial, the LI12542F6 group also showed significantly increased MUAC and improved body composition and serum hormone levels. The participants' hematology, clinical chemistry, and vital signs were within the normal range. No adverse events were observed.

CONCLUSION

This study demonstrates that LI12542F6 supplementation significantly increases muscle strength and size and improves endurance in healthy men. Also, LI12542F6 is well-tolerated by the participants.