The Commission of Small Island States on Climate Change and International Law in December 2022 requested for an advisory opinion to the International Tribunal for the Law of the Sea (ITLOS) for holding States responsible for failure to protect the marine environment caused by climate change and greenhouse gas emissions. This article first examines the dilemma climate regime is facing. Then the article explores why the advisory opinion can serve as “medicine” by examining the potential positive and negative spillover effects of the advisory opinion from the perspective of both jurisdiction and merits. Just like all medicines have side-effects, the climate advisory opinion brings both challenges or opportunities to current climate negotiations, which the article calls for stakeholders to utilize and proceed carefully and cautiously.