What is more powerful than ashwagandha?

Could you elaborate on what substances or herbs might possess a greater potency or effectiveness than ashwagandha, a well-known adaptogen and stress reliever? Are there any natural remedies, supplements, or even pharmaceutical drugs that are considered to be stronger or more impactful in their respective therapeutic areas? Additionally, what factors should be considered when comparing the strengths of different substances, such as their mechanisms of action, potential side effects, and individual variations in response?