Sealeo replaces expanded polystyrene and synthetic gel packs with a compostable, seaweed-based system engineered for pharmaceutical cold chains. Combining a lightweight insulation foam with a high-performance, bio-based coolant, it maintains temperatures 2.5 times longer than standard options and offers a 30% improvement in thermal performance. The system is passive, petroleum-free, and scalable for low-resource settings. Sealeo reduces waste, emissions, and medical spoilage, offering a sustainable logistics solution that supports both environmental goals and public health