Extra Strength TYLENOL® Back Pain Caplets have a muscle relaxant to release seized back muscles plus the trusted pain relief of TYLENOL®. Product information is provided by the product vendor. This content is a summary for informational purposes only and does not have all possible information about this product. It should not be used as a substitute for advice from health care professionals, as this information alone does not assure that this product is safe, effective, or appropriate for you. For more detailed information on this product, including reported and possible side effects and contraindications, refer to the manufacturer's monograph, or speak with a health care provider.