Arginine silicate inositol (ASI) is a compound combining L-arginine, silicon, and inositol, and is marketed as a dietary supplement for supporting exercise performance and recovery. The rationale for its use is based on the potential for L-arginine to increase nitric oxide (NO) levels, which may enhance blood flow, oxygen delivery, and nutrient transport to muscles during exercise. Silicon may contribute to connective tissue health. A limited number of small, placebo-controlled studies have examined ASI in the context of exercise. For example, a 2015 pilot study by Kalman et al. (Journal of the International Society of Sports Nutrition) found that 1.5 g/day of ASI for four days improved some measures of muscular strength and blood flow in healthy men. Another study indicated that ASI supplementation might reduce perceived muscle soreness and accelerate post-exercise recovery. However, the body of literature remains sparse, with few independent or long-term trials, and sample sizes are small. The evidence is promising but preliminary, warranting a rating of 2 out of 5. Overall, while initial results suggest potential benefits of ASI for exercise-related outcomes, more robust, large-scale, and long-term studies are needed to confirm efficacy and establish optimal dosing and safety.