Background <p>Muscle-building supplements (MBS) are increasingly used by athletes and young adults to enhance muscle mass, recovery, and performance. However, inappropriate use and misinformation pose significant health risks. Community pharmacists are well-positioned to provide guidance, yet their readiness in this domain remains underexplored in Saudi Arabia.</p> Methods <p>A descriptive, cross-sectional study was conducted among licensed community pharmacists across Saudi Arabia. A structured, self-administered questionnaire assessed knowledge, attitudes, counseling practices, perceived barriers, and training needs related to MBS. Descriptive statistics, linear regression, and ordinal logistic regression were used to analyze factors associated with knowledge, attitudes, and counseling frequency. A p-value &lt; 0.05 was considered statistically significant.</p> Results <p>A total of 708 pharmacists participated. Higher knowledge scores were associated with male gender, age 26–35, over 10 years of experience, formal training, and frequent supplement-related inquiries. Positive attitudes were linked to male gender, mid-level experience, higher knowledge scores, and frequent customer questions, while formal training was paradoxically associated with slightly lower attitude scores. Counseling frequency was predicted by male gender, age 36–45, and frequent inquiries. Over half of participants supported MBS-related training (54.8%), curriculum integration (55.2%), and standardized counseling guidelines (54.4%).</p> Conclusion <p>Community pharmacists in Saudi Arabia demonstrate varied levels of knowledge and counseling behavior regarding MBS, influenced by demographic factors, training, and customer demand. These findings highlight the need for targeted educational initiatives and national guidance to optimize pharmacists’ role in ensuring the safe use of muscle-building supplements.</p>