Background Shilajit is a mineral-rich natural exudate traditionally used as a rejuvenator and performance enhancer. While previous studies have evaluated standardized Shilajit extracts, there is limited clinical evidence on the traditional resin formulation. This study aimed to assess the safety and efficacy profile of Shilajit resin supplementation on physical performance parameters and blood biomarkers in healthy, moderately active adults. Methods This was an open-label, single-arm pilot clinical study conducted over 28 days in 25 healthy male participants aged 21-55 years. Participants received 500 mg/day of TruBlk™ Shilajit Resin (250 mg twice daily). Primary outcomes included changes in muscle strength (one-repetition maximum 1RM leg press), muscle endurance, grip strength, fatigue severity (Fatigue Severity Scale FSS), and rating of perceived exertion (RPE). Secondary outcomes included aerobic capacity (maximal oxygen uptake VO₂ max), body composition parameters, inflammatory markers like C-reactive protein (CRP) levels, muscle damage markers such as creatine kinase (CK) and lactate dehydrogenase (LDH), and hormonal markers (total testosterone). Safety was evaluated through adverse event monitoring and laboratory assessments, including liver and kidney function tests and hematological parameters. Results After 28 days of supplementation, statistically significant and large magnitude within-group improvements were observed in 1RM leg press strength (+12.94%, p < 0.001), muscle endurance (+12.30%, p < 0.001), grip strength of the dominant hand (+5.73%, p = 0.038), and VO₂ max (+1.36%, p < 0.001). FSS scores decreased by 32.40% (p < 0.001), and RPE scores decreased by 23.63% (p < 0.001). CRP levels significantly declined by 25.35% (p = 0.023). Further, CK levels decreased by 41.70% (p = 0.059, a non-significant trend that, considering the high inter-individual variability at baseline, suggests a potential meaningful reduction in exercise-induced muscle damage and improved recovery status. This should be a key focus of future larger-scale studies. Body composition analysis demonstrated a statistically significant increase in lean body mass (+1.5%, p = 0.002) and a reduction in body fat percentage (-2.34%, p = 0.033). No serious adverse events were reported, and all safety laboratory parameters remained within normal limits. Conclusions Shilajit resin supplementation at a dose of 500 mg/day for 28 days was associated with statistically significant improvements in muscle strength, endurance, aerobic capacity, and fatigue parameters, along with favorable changes in inflammatory markers, while demonstrating good safety and tolerability in healthy adult males. These findings support further investigation of Shilajit resin in larger, randomized, placebo-controlled clinical trials.
Yadav et al. (Tue,) studied this question.